We Are Sunshine

UV→D NOW – Understanding the importance of sun exposure for health

Friday, November 13th, 2020

By Perry Holman, Executive Director, Vitamin D Society

COVID-19 has spawned an entirely new angle of ultraviolet and vitamin D research in 2020 – bringing the role of UV and vitamin D into the health of your immune system into the forefront once again.

Research studies over the past 6 months have been consistent: People with higher vitamin D levels, naturally produced when your skin is exposed to UVB light from the sun, have a reduced risk of catching COVID-19 and a less severe outcome if they do contract the virus 1, 2, 3, 4, 5.

COVID-19 cases dropped substantially during our Canadian summer when people were out in the sunlight making vitamin D in their skin.

This is why we are focusing Vitamin D Awareness Month in 2020 on the main source of vitamin D: sunshine.

Vitamin D awareness has increased in Canada in the past decade, but vitamin D deficiency and insufficiency still remains an issue for most Canadians. We think the reason is because most Canadians are unsure about getting vitamin D from sun exposure – the way our bodies were designed to make it.

So, this year we wanted to build upon this vitamin D knowledge base and extend it to address the importance of sunlight and the benefits of moderate UV exposure and encourage people to take action due to the low levels we see in Canada from October to May.

The Vitamin D Society has created a new program called “UVD NOW!” The reason: COVID-19 has taught us once again that the potential benefits of vitamin D lie in levels you only get naturally if you get regular non-burning sun exposure. And the evidence that the benefits of non-burning sun exposure go beyond simple vitamin D production is stronger than ever.

Dr. Michael F Holick, a world-renowned vitamin D researcher and author said: “If the body could say which method it prefers to get its daily dose of vitamin D, it would hands down give a standing ovation to sunlight sources of vitamin D rather than a bottle. After all, why else would it spend so many millions of years perfecting this clever self-regulating process?”

It’s true. While supplements are a good secondary method of vitamin D intake, dietary and supplementary vitamin D does not self-regulate this way.

Your body was designed to make vitamin D – not to take it.

The science brought forward as a result of and during the COVID-19 pandemic in 2020 has made it clear that regular, non-burning UV exposure is essential for Canadians for a number of reasons:

  • Natural vitamin D levels – those that can be achieved by regular UV exposure – are strongly associated with both reduced risk of COVID-19 and reduced severity of symptoms in those who contract it.
  • There are many other non-Vitamin D related health benefits that now appear to be tied to regular UV exposure – not just to vitamin D produced from UV. For example:
    • Nitric Oxide (NO) through vasodilatation and lowering of blood pressure reduces CVD
    • Serotonin is a neurotransmitter involved not only in mood, but also in cognition, regulation of feeding behavior, anxiety, aggression, pain, sexual activity, and sleep
    • Endorphins released into the blood during UV exposure, may reach the brain in sufficient concentrations to induce mood enhancement and relaxation, reduce depression and provide pain relief
    • Melatonin has a potent anti-oxidant effect
    • UV light treats the symptoms of and may help prevent skin diseases such as psoriasis, eczema, vitiligo, acne
    • UV light regulates circadian rhythm – circadian clock, which effects mood, sleep, and cognition

Vitamin D levels drop naturally during the winter because of the angle of the sun, clothing we wear and more time is spent indoors, which may make you more vulnerable to viruses and infections such as COVID-19, flu and colds.

Adults will need a vitamin D intake of 4,000 IU/day (100 mcg) from all sources; sun, artificial UVB, food and possibly supplements. A group of 48 vitamin D expert scientists have recommended that everyone, all ages, achieve a vitamin D blood level of 25(OH)D level of between 100-150 nmol/L or 40-60 ng/ml (USA). Currently 93% of Canadians do not meet this level at any time of the year.

The only way you will know if you have enough vitamin D is to have a 25(OH)D test. This can be done at your doctor’s office, or you can get a home test at

Your body is its own vitamin D factory. All it needs is UVB exposure on your skin to do the job. To make vitamin D in your skin naturally from sunlight the UV Index needs to be above 3 and your shadow shorter than you. In the winter when the UVB in sunlight is to weak to reach earth you can consider the use of artificial UVB devices such as sunbeds which stimulate your body’s natural production of vitamin D.

Canadian researcher Dr. Samantha Kimball has published research showing that a typical sunbed emitting UVB and UVA light in Canada can get you to optimum vitamin D blood levels6. “People who use tanning salons, specifically sunbeds that have UVB during the winter reach physiological blood levels (>100 nmol/L) of vitamin D” said Kimball.

The significant risks of overexposure to UV are tied to intermittent sunburn – and we know that 33% of Canadians sunburn every year. Because a large portion of Canadians report sunburns every year, we need a better conversation on how to harness the potential benefits of regular non-burning UV exposure. The Vitamin D Society joins with others who have called for a better national conversation on the need for regular, non-burning UV exposure as the best source of vitamin D and other photo-related benefits.

To help reduce your risk of burning from sun exposure make sure you know your skin and skin type. When outdoors assess the strength of sun exposure. Make sure you do not burn. Start off slowly and gradually increase your sun exposure time until your skin has fully acclimatized to it.


  1. Kaufman HW, Niles JK, Kroll MH, Bi C, Holick MF. SARS-CoV-2 positivity rates associated with circulating 25-hydroxyvitamin D levels PLoS One. 2020 Sep 17;15(9):e0239252. doi: 10.1371/journal.pone.0239252. PMID: 32941512; PMCID: PMC7498100.
  1. Maghbooli, Z., Sahraian, M. A., Ebrahimi, M., Pazoki, M., Kafan, S., Tabriz, H. M., Hadadi, A., Montazeri, M., Nasiri, M., Shirvani, A., & Holick, M. F. (2020). Vitamin D sufficiency, a serum 25-hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection. PloS one15(9), e0239799.
  1. Meltzer DO, Best TJ, Zhang H, Vokes T, Arora V, Solway J. Association of Vitamin D Status and Other Clinical Characteristics With COVID-19 Test Results. JAMA Netw Open. 2020 Sep 1;3(9):e2019722. doi: 10.1001/jamanetworkopen.2020.19722. PMID: 32880651; PMCID: PMC7489852.
  1. Castillo E, Costa LME, Barrios JMV, Díaz JFA, Miranda JL, Bouillon R, Gomez JMQ (2020). “Effect of calcifediol treatment and best available therapy versus best available therapy on intensive care unit admission and mortality among patients hospitalized for COVID-19: A pilot randomized clinical study”. The Journal of steroid biochemistry and molecular biology203, 105751.
  1. Merzon E, Tworowski D, Gorohovski A, Vinker S, Cohen AG, Green I, Morgenstern  MF. (2020). Low plasma 25(OH) vitamin D level is associated with increased risk of COVID-19 infection: an Israeli population-based study. The FEBS journal, 10.1111/febs.15495. Advance online publication.
  1. Kimball SM, Lee J, Vieth R. Sunbeds with UVB radiation can produce physiological levels of serum 25-Hydroxyvitamin D in healthy volunteers. Dermatoendocrinol. 2017 Oct 17;9(1):e1375635. doi: 10.1080/19381980.2017.1375635. PMID: 29484099; PMCID: PMC5821157.