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Information on the latest vitamin D news and research.

Find out more information on deficiency, supplementation, sun exposure, and how vitamin D relates to your health.

Vitamin D supplementation and sun exposure: Can we pick and choose?

Despite the increased risk of non-melanoma skin cancers, the Vitamin D Council recommends moderate sun exposure and 5,000 IU of vitamin D3 on days you do not get sun exposure. We are not alone. Recent studies imply that sun exposure does more than simply make vitamin D and that one cannot fully replace the benefits of sun exposure by simply taking a vitamin D supplement.

Dr. Prue Hart of the University of Western Australia makes these points in a recent paper.

Hart PH. Vitamin D supplementation, moderate sun exposure, and control of immune Diseases. Discov Med. 2012 Jun;13(73):397-404.

She contends that sunshine affects the immune system via non-vitamin D mechanisms as well as vitamin D mechanisms by citing both human and animal studies. She argues, “It is possible that moderate sun exposure and vitamin D supplementation may be complementary for maximal control of immune-driven diseases.”

She also points out that over the last two decades vitamin D levels have fallen about twenty percent while the incidence of immune system diseases,  such as multiple sclerosis, type 1 diabetes, and asthma have all increased during that same time period. Dr. Hart cited evidence that vitamin D is crucial to brain functioning and added autism as a vitamin D/sunshine related disease. She predicts, “Within ten years, we should have a clearer answer from randomized controlled studies as to whether vitamin D per se can reduce the incidence and progression of immune diseases, cardiovascular disease, autism, and more.”

In regards to sun exposure recommendations, Hart stated, “Repeated short sun exposures to a larger body surface area are likely to have a greater effect than longer exposures of smaller areas.”  Of course, few of us are in a situation that allows large surface area exposures every day. However, weekends and holidays offer the opportunity of nearly full body short sun exposures for both adults and children. On the days one gets such exposure, there is no need to take oral vitamin D supplementation.

Ten years is a long time to wait for the randomized controlled trials that many believe will settle the vitamin D issue. During those ten years, it seems wise to protect you and your family with at least some moderate sun exposure combined with adequate daily doses of vitamin D3 on sunless days.

  About: John Cannell, MD

Dr. John Cannell is founder of the Vitamin D Council. He has written many peer-reviewed papers on vitamin D and speaks frequently across the United States on the subject. Dr. Cannell holds an M.D. and has served the medical field as a general practitioner, emergency physician, and psychiatrist.

11 Responses to Vitamin D supplementation and sun exposure: Can we pick and choose?

  1. roger.rolfe@sympatico.ca says:

    Thanks for this post. It confirms what my body tells me. Vitamin D supplementation really improved my health and well-being. I started in Jan, 2010 taking 4000IU per day. I live in Toronto, Canada so this was in the middle of a Canadian winter. In April, I wondered why I had so much energy and why my winter health was so good. I knew it was the D3 since I hadn’t changed anything else in my health & nutrition regimen. I used to be always tired mid-afternoon. I could hardly keep my eyes open from 2:30 to 3:30pm. That’s what changed first. I wasn’t tired anymore. Today I look back on that time and laugh. I have lots of energy reserves, where before I felt I had to ration my energy constantly. But that said, my body feels the best in the summertime. Doesn’t everyone say this? The sense of health and wellbeing is always strongest this time of year. So I wouldn’t be surprized that moderate sun exposure provides more than just the D benefit. Even though I work in an office, at a computer, all day, I take walks at lunch and have a sun bath every day I can. Thanks again for your website and your posts. I”m a big fan.

  2. roger.rolfe@sympatico.ca says:

    Spelling alert: The word in Dr. Hart’s quote, parag. 4, should be “complementary”, not “complimentary”.

  3. Brant Cebulla says:

    Thanks Roger. Noted and corrected.

  4. Ian says:

    Professor Hart is a woman actually.

  5. BrianYYC says:

    Toronto is at Latitude 43 Deg. 40 min. N. We live in Calgary at 51 deg. 1 min. N where the sun during the winter is almost non existent. Sunscreen is not in our house and we take 9000 IU/day of Vitamin D3 all year except for those days when we get out into the sun for a few hours. We get tested every 6 months as we are in a study on Vitamin D and our levels are in the high normal range, but certainly not toxic. We literally never get sick or have colds and all our “numbers” are within normal range. I’m 67 and my wife is 58 and we feel great. The biggest problem we have is trying to convince others to take more than 400 to 1000 IU of Vit. D3 every day. The medical establishment has so brainwashed people into believing the :”system” that they are afraid to try anything natural. Thank you for a wonderfully informative website.

  6. Heatwave says:

    People need to understand when they go outside or a tanning bed to get this vitamin D they need not put on sunscreens as sunscreens block the vitamin D production. Too many people go outside thinking they are doing good but have sunscreen on which doesn’t do anyone any good as sunscreens prevent the body from make vitamin D. I’m a firm believer in “vitamin D” the natural way. Supplements just aren’t the same. I have been a moderate tanner for 9 yrs. I do not get colds or the flu in the winter time. I used to get strepp 3-4 times a year. I also I don’t get burnt in the summertime due to having a base tan to naturally protect myself. :) It is all about moderation. The benefits out way the risk.

  7. boston says:

    Do you not think that just getting the sun light in one’s eyes outside does a great deal for the body’s health—even if it is in the shade. I have read a lot about the good of “natural light” for the body’s health…..I believe that is why they make those natural light bulbs–like Ott’s.

  8. Dan says:

    To say sun exposure provides additional benefits beyond Vitamin D is vague at best. Why are there no studies of sun exposure on body chemicals?

  9. Brant Cebulla says:

    Dan, good question. I think researchers interested in sun exposure still feel like they have a lot of work to do in the field of vitamin D.

  10. Rebecca Oshiro says:

    Dan, there is a recent study investigating the beneficial effects of UV radiation via other pathways than vitamin D production: