{"id":27609,"date":"2026-02-27T11:02:05","date_gmt":"2026-02-27T16:02:05","guid":{"rendered":"https:\/\/news.smarttan.com\/?p=27609"},"modified":"2026-02-27T11:02:05","modified_gmt":"2026-02-27T16:02:05","slug":"the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low","status":"publish","type":"post","link":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/","title":{"rendered":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low"},"content":{"rendered":"<p>Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient.<\/p>\n<p>In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade.<\/p>\n<p>For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0<i>is<\/i>\u00a0new is that this issue is finally receiving broader public and professional attention.<\/p>\n<h4>WATCH DR. CAMPBELL\u2019S VIDEO<\/h4>\n<div class=\"epyt-video-wrapper fluid-width-video-wrapper\"><iframe id=\"_ytid_42813\" class=\"__youtube_prefs__ no-lazyload\" title=\"Vitamin D mistake\" src=\"https:\/\/www.youtube.com\/embed\/AtoxkK7MeKc?enablejsapi=1&amp;autoplay=0&amp;cc_load_policy=0&amp;cc_lang_pref=&amp;iv_load_policy=1&amp;loop=0&amp;rel=1&amp;fs=1&amp;playsinline=0&amp;autohide=2&amp;theme=dark&amp;color=red&amp;controls=1&amp;\" allowfullscreen=\"allowfullscreen\" data-origwidth=\"860\" data-origheight=\"484\" data-no-lazy=\"1\" data-skipgform_ajax_framebjll=\"\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<hr \/>\n<h3>The Heart of the Error: \u201cAverage vs. Individual\u201d<\/h3>\n<p>When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a0<b>97.5% of the population<\/b>\u00a0would reach a serum 25(OH)D level of at least\u00a0<b>20 ng\/ml (50 nmol\/L)<\/b>.<\/p>\n<p>The problem lies in\u00a0<i>how<\/i>\u00a0that calculation was made.<\/p>\n<p>Instead of analyzing\u00a0<b>individual participant data<\/b>\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy.<\/p>\n<p>Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered.<\/p>\n<p>GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0<a href=\"https:\/\/www.grassrootshealth.net\/blog\/iom-miscalculated-rda-vitamin-d\/\">\u201cIOM Miscalculated the RDA for Vitamin D\u201d<\/a>, which clearly explains how this statistical oversight led to an RDA that fails most individuals.<\/p>\n<h3>How Big Is the Mistake?<\/h3>\n<p>When the same data are analyzed correctly at the individual level, the results are startling:<\/p>\n<ul>\n<li aria-level=\"1\"><b>600 IU\/day<\/b>\u00a0raises serum vitamin D to only\u00a0<b>10.7 ng\/mL (26.8 nmol\/L)<\/b>\u00a0for 97.5% of people well below sufficiency.<\/li>\n<li aria-level=\"1\">To ensure nearly everyone reaches\u00a0<b>20 ng\/ml<\/b>, intake may need to be as high as\u00a0<b>8,895 IU\/day<\/b>.<\/li>\n<\/ul>\n<p>That means:<\/p>\n<ul>\n<li aria-level=\"1\">The U.S. RDA may be nearly\u00a0<b>15 times too low<\/b><\/li>\n<li aria-level=\"1\">The UK RDA may be more than\u00a0<b>22 times too low<\/b><\/li>\n<\/ul>\n<p>GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations.<\/p>\n<h3>Not New Science, Just Long Ignored<\/h3>\n<p>This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0<em>Practical Uses of Vitamin D for Disease Prevention<\/em>, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved.<\/p>\n<h4>WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR<\/h4>\n<div class=\"epyt-video-wrapper fluid-width-video-wrapper\"><iframe id=\"_ytid_41179\" class=\"__youtube_prefs__ no-lazyload\" title=\"Practical Uses of Vitamin D for Disease Prevention | Dr. Michael Holick\" src=\"https:\/\/www.youtube.com\/embed\/JIxCvr0uu-c?enablejsapi=1&amp;autoplay=0&amp;cc_load_policy=0&amp;cc_lang_pref=&amp;iv_load_policy=1&amp;loop=0&amp;rel=1&amp;fs=1&amp;playsinline=0&amp;autohide=2&amp;theme=dark&amp;color=red&amp;controls=1&amp;\" allowfullscreen=\"allowfullscreen\" data-origwidth=\"860\" data-origheight=\"484\" data-no-lazy=\"1\" data-skipgform_ajax_framebjll=\"\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy:<\/p>\n<ul>\n<li aria-level=\"1\"><a href=\"https:\/\/www.grassrootshealth.net\/blog\/current-recommendations-low\/\">\u201cCurrent Recommendations Are Too Low\u201d<\/a>\u00a0highlights how existing guidelines fail to prevent deficiency.<\/li>\n<li aria-level=\"1\"><a href=\"https:\/\/www.grassrootshealth.net\/blog\/grassrootshealth-data-supports-much-higher-intake-of-vitamin-d-than-the-current-rda\/\">\u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d<\/a>\u00a0presents real-world evidence from thousands of participants.<\/li>\n<li aria-level=\"1\"><a href=\"https:\/\/www.grassrootshealth.net\/blog\/big-mistake-iom\/\">\u201cBig Mistake by the IOM\u201d<\/a>\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms.<\/li>\n<\/ul>\n<p>For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked.<\/p>\n<h3>Why This Matters for Public Health<\/h3>\n<p><strong>Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with:<\/strong><\/p>\n<ul>\n<li aria-level=\"1\">Increased fracture risk and bone disease<\/li>\n<li aria-level=\"1\">Higher incidence of certain cancers, including colorectal and prostate cancer<\/li>\n<li aria-level=\"1\">Elevated risk of type 1 and type 2 diabetes<\/li>\n<li aria-level=\"1\">Impaired immune function<\/li>\n<li aria-level=\"1\">Greater risk of cognitive decline and dementia<\/li>\n<li aria-level=\"1\">Much more\u2026<\/li>\n<\/ul>\n<p>In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health.<\/p>\n<h3>Growing Attention<\/h3>\n<p>In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0<a href=\"https:\/\/substack.com\/@popularrationalism\/p-181070305\" target=\"_blank\" rel=\"noopener\"><i>Popular Rationalism<\/i><\/a>. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction.<\/p>\n<p>This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0<b>the science has been clear yet policy remains in the Dark Ages<\/b>.<\/p>\n<h3>What Should Be Done Now?<\/h3>\n<p>Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for:<\/p>\n<ul>\n<li aria-level=\"1\">Evidence-based vitamin D intake recommendations<\/li>\n<li aria-level=\"1\">Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation<\/li>\n<li aria-level=\"1\">Public health policies that reflect biological variability and current evidence<\/li>\n<\/ul>\n<p>Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake.<\/p>\n<h3>Conclusion<\/h3>\n<p>A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue.<\/p>\n<p>GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW.<\/p>\n<p><a href=\"https:\/\/www.grassrootshealth.net\/blog\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\" target=\"_blank\" rel=\"noopener\">Click here to read more from GrassrootsHealth.<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p><i>SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business.<\/i><\/p>\n<p><i>\u00a9 2026 International Smart Tan Network. All rights reserved.<\/i><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient. In a December 7, 2025 video, Dr. John [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":27611,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-27609","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.2 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News<\/title>\n<meta name=\"description\" content=\"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient.  In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade.  For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO     The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L).  The problem lies in\u00a0how\u00a0that calculation was made.  Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy.  Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered.  GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling:   600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency.  To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day.  That means:   The U.S. RDA may be nearly\u00a015 times too low  The UK RDA may be more than\u00a022 times too low  GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR  GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy:   \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency.  \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants.  \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms.  For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with:   Increased fracture risk and bone disease  Higher incidence of certain cancers, including colorectal and prostate cancer  Elevated risk of type 1 and type 2 diabetes  Impaired immune function  Greater risk of cognitive decline and dementia  Much more\u2026  In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction.  This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for:   Evidence-based vitamin D intake recommendations  Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation  Public health policies that reflect biological variability and current evidence  Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue.  GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW.  Click here to read more from GrassrootsHealth.  &nbsp;  &nbsp;  &nbsp;  SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business.  \u00a9 2026 International Smart Tan Network. All rights reserved.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News\" \/>\n<meta property=\"og:description\" content=\"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient.  In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade.  For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO     The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L).  The problem lies in\u00a0how\u00a0that calculation was made.  Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy.  Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered.  GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling:   600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency.  To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day.  That means:   The U.S. RDA may be nearly\u00a015 times too low  The UK RDA may be more than\u00a022 times too low  GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR  GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy:   \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency.  \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants.  \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms.  For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with:   Increased fracture risk and bone disease  Higher incidence of certain cancers, including colorectal and prostate cancer  Elevated risk of type 1 and type 2 diabetes  Impaired immune function  Greater risk of cognitive decline and dementia  Much more\u2026  In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction.  This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for:   Evidence-based vitamin D intake recommendations  Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation  Public health policies that reflect biological variability and current evidence  Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue.  GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW.  Click here to read more from GrassrootsHealth.  &nbsp;  &nbsp;  &nbsp;  SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business.  \u00a9 2026 International Smart Tan Network. All rights reserved.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\" \/>\n<meta property=\"og:site_name\" content=\"Smart Tan News\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/SmartTan\" \/>\n<meta property=\"article:published_time\" content=\"2026-02-27T16:02:05+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1194\" \/>\n\t<meta property=\"og:image:height\" content=\"640\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"smarttannews\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@SmartTan\" \/>\n<meta name=\"twitter:site\" content=\"@SmartTan\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"smarttannews\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"5 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#article\",\"isPartOf\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\"},\"author\":{\"name\":\"smarttannews\",\"@id\":\"https:\/\/news.smarttan.com\/#\/schema\/person\/722dc7049af55e0ed743d67ce9ed4819\"},\"headline\":\"The Big Vitamin D Mistake: Why the RDA is Dangerously Low\",\"datePublished\":\"2026-02-27T16:02:05+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\"},\"wordCount\":1116,\"publisher\":{\"@id\":\"https:\/\/news.smarttan.com\/#organization\"},\"image\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg\",\"articleSection\":[\"News\"],\"inLanguage\":\"en-US\"},{\"@type\":\"WebPage\",\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\",\"url\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\",\"name\":\"The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News\",\"isPartOf\":{\"@id\":\"https:\/\/news.smarttan.com\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage\"},\"image\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage\"},\"thumbnailUrl\":\"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg\",\"datePublished\":\"2026-02-27T16:02:05+00:00\",\"description\":\"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient. In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade. For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L). The problem lies in\u00a0how\u00a0that calculation was made. Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy. Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered. GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling: 600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency. To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day. That means: The U.S. RDA may be nearly\u00a015 times too low The UK RDA may be more than\u00a022 times too low GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy: \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency. \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants. \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms. For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with: Increased fracture risk and bone disease Higher incidence of certain cancers, including colorectal and prostate cancer Elevated risk of type 1 and type 2 diabetes Impaired immune function Greater risk of cognitive decline and dementia Much more\u2026 In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction. This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for: Evidence-based vitamin D intake recommendations Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation Public health policies that reflect biological variability and current evidence Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue. GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW. Click here to read more from GrassrootsHealth. &nbsp; &nbsp; &nbsp; SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business. \u00a9 2026 International Smart Tan Network. All rights reserved.\",\"breadcrumb\":{\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage\",\"url\":\"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg\",\"contentUrl\":\"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg\",\"width\":1194,\"height\":640,\"caption\":\"Woman wearing yellow shirt and holding of vitamin D capsules,glass of water.Health care concept\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\/\/news.smarttan.com\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"The Big Vitamin D Mistake: Why the RDA is Dangerously Low\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/news.smarttan.com\/#website\",\"url\":\"https:\/\/news.smarttan.com\/\",\"name\":\"Smart Tan News\",\"description\":\"\",\"publisher\":{\"@id\":\"https:\/\/news.smarttan.com\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\/\/news.smarttan.com\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\/\/news.smarttan.com\/#organization\",\"name\":\"Smart Tan\",\"url\":\"https:\/\/news.smarttan.com\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/news.smarttan.com\/#\/schema\/logo\/image\/\",\"url\":\"https:\/\/smarttan.com\/news\/wp-content\/uploads\/2022\/08\/Smart-Tan.png\",\"contentUrl\":\"https:\/\/smarttan.com\/news\/wp-content\/uploads\/2022\/08\/Smart-Tan.png\",\"width\":500,\"height\":164,\"caption\":\"Smart Tan\"},\"image\":{\"@id\":\"https:\/\/news.smarttan.com\/#\/schema\/logo\/image\/\"},\"sameAs\":[\"https:\/\/www.facebook.com\/SmartTan\",\"https:\/\/x.com\/SmartTan\"]},{\"@type\":\"Person\",\"@id\":\"https:\/\/news.smarttan.com\/#\/schema\/person\/722dc7049af55e0ed743d67ce9ed4819\",\"name\":\"smarttannews\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g\",\"caption\":\"smarttannews\"},\"url\":\"https:\/\/news.smarttan.com\/index.php\/author\/smarttannews\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News","description":"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient.  In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade.  For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO     The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L).  The problem lies in\u00a0how\u00a0that calculation was made.  Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy.  Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered.  GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling:   600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency.  To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day.  That means:   The U.S. RDA may be nearly\u00a015 times too low  The UK RDA may be more than\u00a022 times too low  GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR  GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy:   \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency.  \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants.  \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms.  For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with:   Increased fracture risk and bone disease  Higher incidence of certain cancers, including colorectal and prostate cancer  Elevated risk of type 1 and type 2 diabetes  Impaired immune function  Greater risk of cognitive decline and dementia  Much more\u2026  In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction.  This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for:   Evidence-based vitamin D intake recommendations  Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation  Public health policies that reflect biological variability and current evidence  Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue.  GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW.  Click here to read more from GrassrootsHealth.  &nbsp;  &nbsp;  &nbsp;  SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business.  \u00a9 2026 International Smart Tan Network. All rights reserved.","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/","og_locale":"en_US","og_type":"article","og_title":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News","og_description":"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient.  In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade.  For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO     The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L).  The problem lies in\u00a0how\u00a0that calculation was made.  Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy.  Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered.  GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling:   600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency.  To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day.  That means:   The U.S. RDA may be nearly\u00a015 times too low  The UK RDA may be more than\u00a022 times too low  GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR  GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy:   \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency.  \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants.  \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms.  For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with:   Increased fracture risk and bone disease  Higher incidence of certain cancers, including colorectal and prostate cancer  Elevated risk of type 1 and type 2 diabetes  Impaired immune function  Greater risk of cognitive decline and dementia  Much more\u2026  In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction.  This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for:   Evidence-based vitamin D intake recommendations  Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation  Public health policies that reflect biological variability and current evidence  Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue.  GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW.  Click here to read more from GrassrootsHealth.  &nbsp;  &nbsp;  &nbsp;  SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business.  \u00a9 2026 International Smart Tan Network. All rights reserved.","og_url":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/","og_site_name":"Smart Tan News","article_publisher":"https:\/\/www.facebook.com\/SmartTan","article_published_time":"2026-02-27T16:02:05+00:00","og_image":[{"width":1194,"height":640,"url":"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg","type":"image\/jpeg"}],"author":"smarttannews","twitter_card":"summary_large_image","twitter_creator":"@SmartTan","twitter_site":"@SmartTan","twitter_misc":{"Written by":"smarttannews","Est. reading time":"5 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#article","isPartOf":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/"},"author":{"name":"smarttannews","@id":"https:\/\/news.smarttan.com\/#\/schema\/person\/722dc7049af55e0ed743d67ce9ed4819"},"headline":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low","datePublished":"2026-02-27T16:02:05+00:00","mainEntityOfPage":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/"},"wordCount":1116,"publisher":{"@id":"https:\/\/news.smarttan.com\/#organization"},"image":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage"},"thumbnailUrl":"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg","articleSection":["News"],"inLanguage":"en-US"},{"@type":"WebPage","@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/","url":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/","name":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low - Smart Tan News","isPartOf":{"@id":"https:\/\/news.smarttan.com\/#website"},"primaryImageOfPage":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage"},"image":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage"},"thumbnailUrl":"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg","datePublished":"2026-02-27T16:02:05+00:00","description":"Vitamin D has long been recognized as essential for bone health, immune function, and chronic disease prevention. Yet despite decades of research, official recommendations for daily vitamin D intake remain way too low\u2026 so low, in fact, that they leave a large portion of the population deficient. In a December 7, 2025 video, Dr. John Campbell brought renewed attention to what he describes as a \u201cschoolboy error\u201d in the calculation of the Recommended Dietary Allowance (RDA) for vitamin D, an error that has gone uncorrected for more than a decade. For the GrassrootsHealth community, however, this is not breaking news. This statistical mistake and its serious public health implications, has been documented, analyzed, and communicated by GrassrootsHealth scientists (such as Dr. Michael Holick, featured in the following video) for years. What\u00a0is\u00a0new is that this issue is finally receiving broader public and professional attention. WATCH DR. CAMPBELL\u2019S VIDEO The Heart of the Error: \u201cAverage vs. Individual\u201d When the U.S. Institute of Medicine (IOM), now the National Academy of Medicine, established the vitamin D RDA, the goal was to ensure that\u00a097.5% of the population\u00a0would reach a serum 25(OH)D level of at least\u00a020 ng\/ml (50 nmol\/L). The problem lies in\u00a0how\u00a0that calculation was made. Instead of analyzing\u00a0individual participant data\u00a0from vitamin D supplementation studies, the IOM averaged results at the study level. This \u201caverage of averages\u201d approach smoothed out natural biological variation and led to a false sense of adequacy. Dr. Campbell explains this with a simple analogy: if the average score in a classroom is a passing grade, that does not mean every student passed. To ensure nearly everyone succeeds, individual performance not averages must be considered. GrassrootsHealth scientists identified and documented this exact issue years ago, including in the blog written by Dr. Robert Heaney,\u00a0\u201cIOM Miscalculated the RDA for Vitamin D\u201d, which clearly explains how this statistical oversight led to an RDA that fails most individuals. How Big Is the Mistake? When the same data are analyzed correctly at the individual level, the results are startling: 600 IU\/day\u00a0raises serum vitamin D to only\u00a010.7 ng\/mL (26.8 nmol\/L)\u00a0for 97.5% of people well below sufficiency. To ensure nearly everyone reaches\u00a020 ng\/ml, intake may need to be as high as\u00a08,895 IU\/day. That means: The U.S. RDA may be nearly\u00a015 times too low The UK RDA may be more than\u00a022 times too low GrassrootsHealth data have long supported this conclusion, showing that\u00a0much higher intakes are required\u00a0to reliably achieve and maintain healthy vitamin D levels across diverse populations. Not New Science, Just Long Ignored This next video, a recording of our Vitamin D Study Hour with Dr. Michael Holick titled\u00a0Practical Uses of Vitamin D for Disease Prevention, reviews decades of vitamin D research as well as the history and shortcomings of the RDA and Endocrine Society\u2019s guidelines for vitamin D. Dr. Holick clearly outlines the evidence showing\u00a0the strong link between vitamin D levels and reduced risk of many chronic diseases, including diabetes, infectious diseases, autoimmune conditions, and cancer. Yet, even with significant decreases in disease risk, these outcomes are not reflected in many current public health guidelines.\u00a0 Dr. Holick explains how this all evolved. WATCH DR. HOLICK\u2019S VITAMIN D STUDY HOUR GrassrootsHealth and our panel of scientists have consistently challenged low official recommendations, publishing analyses and population data that demonstrate their inadequacy: \u201cCurrent Recommendations Are Too Low\u201d\u00a0highlights how existing guidelines fail to prevent deficiency. \u201cGrassrootsHealth Data Supports Much Higher Intake of Vitamin D Than the Current RDA\u201d\u00a0presents real-world evidence from thousands of participants. \u201cBig Mistake by the IOM\u201d\u00a0explains the origin and consequences of the RDA miscalculation in accessible terms. For over a decade, these findings have been available to policymakers, clinicians, and researchers. Unfortunately, they have been largely overlooked. Why This Matters for Public Health Vitamin D deficiency is not limited to bone health concerns. Low vitamin D status has been associated with: Increased fracture risk and bone disease Higher incidence of certain cancers, including colorectal and prostate cancer Elevated risk of type 1 and type 2 diabetes Impaired immune function Greater risk of cognitive decline and dementia Much more\u2026 In countries like Canada, where average dietary intake is only\u00a0232 IU\/day, and in northern regions where winter sun exposure is minimal, deficiency is widespread. Similar challenges exist across the UK and much of Europe.\u00a0\u00a0These realities underscore why relying on outdated RDAs has real consequences for population health. Growing Attention In addition to Dr. Campbell\u2019s widely viewed video, this issue has recently gained further attention, including in a detailed Substack article published by\u00a0Popular Rationalism. Together, these voices reflect a growing recognition that vitamin D guidelines are overdue for correction. This renewed attention validates what GrassrootsHealth researchers and participants have known for years:\u00a0the science has been clear yet policy remains in the Dark Ages. What Should Be Done Now? Correcting the vitamin D RDA is not merely an academic exercise. It is a public health necessity.\u00a0\u00a0GrassrootsHealth continues to advocate for: Evidence-based vitamin D intake recommendations Testing serum 25(OH)D levels with a target level of 40-60 ng\/ml (100-150 nmol\/L) to guide individualized supplementation Public health policies that reflect biological variability and current evidence Until official guidelines are updated, individuals, especially those with limited sun exposure, may benefit from testing their vitamin D levels and working with GrassrootsHealth and others in the vitamin D community to determine appropriate intake. Conclusion A simple statistical error has contributed to decades of inadequate guidance, leaving millions unknowingly deficient.\u00a0 The time to fix the problem and its resulting health consequences is well overdue. GrassrootsHealth has been sounding this alarm for over ten years. With growing public and professional awareness, there is renewed hope that health authorities will finally act.\u00a0\u00a0Correcting this mistake could improve immune health, reduce chronic disease risk, and enhance quality of life worldwide. The science is clear. The data are strong. The time to update vitamin D recommendations is NOW. Click here to read more from GrassrootsHealth. &nbsp; &nbsp; &nbsp; SmartTan.com news articles regularly report medical and scientific information to keep you abreast of current events related to UV light. This information is not intended to be used by any party to make unwarranted health claims to promote sunbed usage. Indoor tanning businesses are obligated to communicate a fair and balanced message to all clients about your products and services including the potential risks associated with indoor tanning. Contact your Smart Tan representative to find out more about what you can and can\u2019t say in your tanning salon business. \u00a9 2026 International Smart Tan Network. All rights reserved.","breadcrumb":{"@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#primaryimage","url":"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg","contentUrl":"https:\/\/news.smarttan.com\/wp-content\/uploads\/2026\/02\/Vitamin-D-2-27-26.jpg","width":1194,"height":640,"caption":"Woman wearing yellow shirt and holding of vitamin D capsules,glass of water.Health care concept"},{"@type":"BreadcrumbList","@id":"https:\/\/news.smarttan.com\/index.php\/the-big-vitamin-d-mistake-why-the-rda-is-dangerously-low\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/news.smarttan.com\/"},{"@type":"ListItem","position":2,"name":"The Big Vitamin D Mistake: Why the RDA is Dangerously Low"}]},{"@type":"WebSite","@id":"https:\/\/news.smarttan.com\/#website","url":"https:\/\/news.smarttan.com\/","name":"Smart Tan News","description":"","publisher":{"@id":"https:\/\/news.smarttan.com\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/news.smarttan.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/news.smarttan.com\/#organization","name":"Smart Tan","url":"https:\/\/news.smarttan.com\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/news.smarttan.com\/#\/schema\/logo\/image\/","url":"https:\/\/smarttan.com\/news\/wp-content\/uploads\/2022\/08\/Smart-Tan.png","contentUrl":"https:\/\/smarttan.com\/news\/wp-content\/uploads\/2022\/08\/Smart-Tan.png","width":500,"height":164,"caption":"Smart Tan"},"image":{"@id":"https:\/\/news.smarttan.com\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/SmartTan","https:\/\/x.com\/SmartTan"]},{"@type":"Person","@id":"https:\/\/news.smarttan.com\/#\/schema\/person\/722dc7049af55e0ed743d67ce9ed4819","name":"smarttannews","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/c0189f76465f47ce293287354f8076bfdb83130e65538eb34fcd2cd44e9f0e53?s=96&d=mm&r=g","caption":"smarttannews"},"url":"https:\/\/news.smarttan.com\/index.php\/author\/smarttannews\/"}]}},"_links":{"self":[{"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/posts\/27609","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/comments?post=27609"}],"version-history":[{"count":1,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/posts\/27609\/revisions"}],"predecessor-version":[{"id":27610,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/posts\/27609\/revisions\/27610"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/media\/27611"}],"wp:attachment":[{"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/media?parent=27609"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/categories?post=27609"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/news.smarttan.com\/index.php\/wp-json\/wp\/v2\/tags?post=27609"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}