By Perry Holman, Executive Director, Vitamin D Society

Key Points:

• No supplement will replace all the benefits of sunlight when considering the full spectrum of light
• UVB exposure on your skin from sunlight makes Vitamin D naturally without ever going to toxic levels
• Most people know about the benefits of vitamin D for bone health. Vitamin D also has benefits for the immune system, cardiovascular health, autoimmune diseases such as diabetes, and multiple sclerosis, skin, and has been linked to lower incidence of many forms of cancer
• UVA exposure releases nitric oxide stores in your skin, helping reduce your blood pressure and improving cardiovascular health
• Visible light is beneficial for skin, sleep, happiness and relaxation
• Infrared light is a powerful antioxidant beneficial for intercellular melatonin used by the mitochondria to repair cell damage
• When sunlight is unavailable or not strong enough, turn to surrogates such as sunbeds, phototherapy units or light boxes
• Overexposure to sunlight has risks too. The key is to know your skin and take care not to burn. Moderation!

We all know how important sunlight exposure is for vitamin D but do you know that sunlight also provides you with many more additional health benefits? As part of our UV->D NOW program we want to show everyone the full benefits of sunlight.

Many people think that taking a vitamin D supplement provides them with all the benefits of sunlight. This is not correct. Sunlight is made up of many different types of rays divided by bandwidths and each has certain unique health benefits not found in a supplement.

To help you understand the different light components found in sunlight check out the chart below:

Ultraviolet rays such as UVA, UVB and UVC cannot be seen by the human eye. UVC rays do not reach earth as they are filtered out and blocked by the ozone layer and atmosphere.

Solar radiation reaching earth is composed of 7% Ultraviolet (UV), 39% visible light, and 54% infrared (Barolet 2015). Of the 7% UV, approximately 95% of that is comprised of UVA and 5% is UVB in summer at midday.

UVB rays reach earth in a limited capacity as most are blocked by the ozone layer and atmosphere. The UVB rays that do get through do so when the sun is high in the sky or directly overhead. This happens mainly in the summer months between 10am and 2pm when the UV index is above 3. In winter depending on your latitude (where you live), the sun may be on an angle so the UVB rays are absorbed by the atmosphere and do not reach the earth.

UVB exposure on your skin is the natural way your body has been designed to produce its vitamin D. Having optimal vitamin D levels of between 100-150 nmol/L is so important for your health. Thousands of studies have been completed which show that vitamin D strengthens your bones and immune system and reduces your risk of cardiovascular disease, autoimmune diseases such as diabetes and multiple sclerosis, and has been linked to lower incidence of many forms of cancer. (Garland 2006)

Sunlight exposure has also been found to promote longevity and reduce your chance of dying. Results from a 20-year follow-up of 29,518 Swedish women, aged 25-64 years, found that those women who avoided sunlight had a two-fold greater chance of dying when compared to those with the highest sun exposure (Lindqvist 2014). This highlights the overall health benefit of sun exposure from its total spectrum, UV, Visible and Infrared.

UVA rays make up the great majority of the UV rays reaching earth. In early morning or late afternoon/early evening, sunlight is almost entirely made up of UVA. Its that small percent of UVB, 5% or less, of exposure around midday that makes the vitamin D in humans.

Visible light are colours you can see in sunlight. That’s why they are called visible. They consist of the colours purple, blue, green, yellow, orange and red.  You can see the wide range of visible light colours in a rainbow made from sunlight outside after a rain. You can also shine white light on a triangular prism to separate the light into colours.

Infrared rays in sunlight cannot be seen but you can feel them as heat on your skin.

We have created a short video for you to watch called “Supplements do not replace sunlight” which can be viewed on our YouTube channel.

Sunlight Benefits not related to UVB and vitamin D and not found in a supplement:

Research has found that blood pressure is consistently lower in summer than winter (Brennan 1982). Blood pressure also rises the further you are from the equator (Rostand 1997). Research studies have shown that whole body UVA irradiation of healthy human skin initiates a pronounced decrease in blood pressure. This decrease is found in both systolic and diastolic blood pressure and occurred immediately after UVA exposure and lasted up to 60 minutes. This reduction was due to the release of nitric oxide stores in the skin caused by UVA exposure. (Oplander 2009)

Small changes in population blood pressure can produce significant reductions in cardiovascular disease and death. Even minor reductions in blood pressure due to enhanced exposure to sunlight could translate into longer life and billions of dollars saved in healthcare every year (Feelisch 2010). A reduction in blood pressure from sun exposure could have profound positive population health implications but will require public health to update their sunlight exposure recommendations.

Dr. Weller, a British dermatologist and researcher into UVA/nitric oxide has said “We suspect the benefits to heart health of sun will outweigh the risk of skin cancer. The work we have done provides a mechanism that may account for this, and also explains why dietary vitamin D supplements alone will not be able to compensate for lack of sun.” (Sorenson & Grant 2018)

Sun exposure can also assist in making sure you’re sleeping properly. Daylight and darkness help control your 24-hour sleep and awake cycle. This is called circadian rhythm. Natural light early in the morning with strong blue light imprints a schedule in your body for sleep later that night. This ensures that you are bright, happy and alert in the daytime and get a good night’s sleep later in the day.  Research has found that blue light is more effective than white light therapy for resetting circadian rhythms, suppressing nighttime melatonin, and enhancing performance (Gooley 2008)

Scientists have recently discovered that there are actually two forms of melatonin produced in your body. The first form called circulatory melatonin, is produced by the pineal gland in your brain and its main function is to help you sleep. The second form called subcellular melatonin, is produced in your skin mainly through the infrared rays found in sun exposure. Subcellular melatonin produced by infrared exposure is a powerful antioxidant used by the mitochondria in our cells to help reduce the damage received from free radicals and oxidative stress.  The amazing thing is that this subcellular melatonin also helps protect you from UV damage in the cells. (Zimmerman 2019)

You can learn more about the power of infrared sunlight and how if produces intercellular melatonin in this video by Dr. Eric Berg. The video was featured in an article by GrassrootsHealth highlighting this new ground breaking research and supporting the recommendation that supplements do not provide everything that the sun does for our health.

Red light treatments have become very popular and have been called the fountain of youth for their ability to promote wound healing, tissue repair, and the capacity to build collagen to help reduce wrinkles. (Wunsch 2014) Red light therapy is atraumatic, meaning that it does not damage your skin because it stimulates the regenerative processes. Researchers have found a new medical use for red light therapy. They found that red light therapy can help improve the healing time of skin damage received during aggressive cancer radiation treatments by 50%. (Mosca 2021)

Do you crave lying out in the warm sunlight? Most people do. Sunlight exposure makes you feel happy and relaxed. There’s a good biological reason for this. Exposure to the UV rays produces beta-endorphins in your skin. These then travel to your brain and make you feel happy. Scientists think this may be an evolutionary adaption to reward you for spending time in the sun to avoid vitamin D deficiency (Nguyen 2019). According to Dr. Michael Holick, “Beta-endorphin, an endogenous opioid peptide, has been demonstrated to improve not only feeling of wellbeing i.e. runners high, but also can cause pain relief and relaxation.” (Holick 2016)

So, what should you do? Sunlight has many health benefits as we reviewed. However, overexposure to sunlight has risks too. The key is to know your skin and take care not to burn. Enjoy sunlight in moderation!

Official recommendations from health authorities are slowly starting to change to accept that sun exposure has many benefits for people’s health. At a recent webinar put on Feb. 17, 2022 by the World Health Organization (WHO) on Striking a balance: harms and benefits of sun exposure, speaker Dr. Rachel Neale recommended “that small regular doses of sun exposure, with sufficient time between them to allow repair of damage, is the preferred method of maintaining vitamin D.”

So, get out in the sunlight when you can. Remember that in the winter if you can’t get outside in the sunlight, there are products available for indoor use such as phototherapy units, sunbeds and light boxes.

Bottom line – No supplements have all the benefits for all the different rays found in sunlight.

References:

1. Barolet D, Christiaens F, Hamblin MR. Infrared and Skin: Friend or Foe.
   J Photochem Photobiol B. 2016 Feb;155:78-85. doi: 10.1016/j.jphotobiol.2015.12.014. https://pubmed.ncbi.nlm.nih.gov/26745730/

2. Garland CF, Garland FC, Gorham ED, Lipkin M, Newmark H, Mohr SB, Holick MF. The role of vitamin D in cancer prevention. Am J Public Health. 2006 Feb;96(2):252-61. doi: 10.2105/AJPH.2004.045260. Epub 2005 Dec 27. PMID: 16380576; PMCID: PMC1470481. https://pubmed.ncbi.nlm.nih.gov/16380576/

3. Linqvist PG, Epstein E, Landin-Olsson M, Ingvar C, Nielsen K, Stenbeck M, Olsson H. Avoidance of sun exposure is a risk factor for all-cause mortality: results from the Melanoma in Southern Sweden cohort. J Intern Med. 2014 Jul;276(1):77-86. doi: 10.1111/joim.12251 https://pubmed.ncbi.nlm.nih.gov/24697969/

4. Brennan PJ, Greenberg G, Miall WE, Thompson SG. Seasonal variation in arterial blood pressure. Br Med J (Clin Res Ed). 1982 Oct 2;285(6346):919-23. https://pubmed.ncbi.nlm.nih.gov/6811068/

5. Rostand SG. Ultraviolet light may contribute to geographic and racial blood pressure differences. Hypertension. 1997 Aug;30(2 Pt 1):150-6. doi: 10.1161/01.hyp.30.2.150. https://pubmed.ncbi.nlm.nih.gov/9260973/

6. Oplander C, Volkmar CM, Paunel-Gorgulu A, van Faassen EE, Heiss C, Kelm M, Halmer D, Murtz M, Pallua N, Suschek CV. Whole body UVA irradiation lowers systemic blood pressure by release of nitric oxide from intracutaneous photolabile nitric oxide derivates. Circ Res. 2009 Nov 6;105(10):1031-40. doi: 10.1161/CIRCRESAHA.109.207019 https://pubmed.ncbi.nlm.nih.gov/19797169/

7. Feelisch M, Kolb-Bachofen V, Liu D, Lundberg JO, Revelo LP, Suschek CV, Weller RB. Is sunlight good for our heart? Eur Heart J. 2010 May;31(9):1041-5. doi: 10.1093/eurheartj/ehq069 https://pubmed.ncbi.nlm.nih.gov/20215123/

8. Sorenson, M.B., & Grant, W.B., (2018) Embrace the Sun (pp93) ISBN: 978-0-692-07600-2

9. Gooley JJ. Treatment of circadian rhythm sleep disorders with light. Ann Acad Med Singap. 2008 Aug;37(8):669-76. https://pubmed.ncbi.nlm.nih.gov/18797560/

10. Zimmerman S, Reiter RJ. Melatonin and the Optics of the Human Body. Melatonin Res. 2019, Vol 2 (1) 138-160; doi: 10.32794/mr11250016  https://www.melatonin-research.net/index.php/MR/article/view/19

11. Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomed Laser Surg. 2014 Feb;32(2):93-100. doi: 10.1089/pho.2013.3616. Epub 2013 Nov 28. PMID: 24286286; PMCID: PMC3926176. https://pubmed.ncbi.nlm.nih.gov/24286286/

12. Mosca RC, Santos SN, Nogueira GEC, Pereira DL, Costa FC, Pereira JX, Zeituni CA, Arany PR. The Efficacy of Photobiomodulation Therapy in Improving Tissue Resilience and Healing of Radiation Skin Damage. Photonics. 2022; 9(1):10. https://doi.org/10.3390/photonics9010010

13. Nguyen NT, Fisher DE. MITF and UV responses in skin: From pigmentation to addiction. Pigment Cell Melanoma Res. 2019 Mar;32(2):224-236. doi: 10.1111/pcmr.12726. Epub 2018 Aug 3. Erratum in: Pigment Cell Melanoma Res. 2020 Mar;33(2):383. PMID: 30019545; PMCID: PMC6336527. https://pubmed.ncbi.nlm.nih.gov/30019545/

14. Holick MF. Biological Effects of Sunlight, Ultraviolet Radiation, Visible Light, Infrared Radiation and Vitamin D for Health. Anticancer Res. 2016 Mar;36(3):1345-56. PMID: 26977036. https://pubmed.ncbi.nlm.nih.gov/26977036/

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