Sun Advice--Expose yourself a little

18 June 2010


If you have followed the news on vitamin D, you may know that a bit of sun exposure can be good for you.  Recent research on vitamin D has shown that getting enough of the “Sunshine Vitamin” can protect against type 1 diabetes, rheumatoid arthritis, multiple sclerosis and autoimmune diseases.  It has also been shown to help prevent osteoporosis, plays a role in weight loss, and one study conducted at Creighton University in Nebraska, showed a 77% decrease in cancer rate for those supplemented with vitamin D.  Another study showed it decreases all-cancer in post menopausal women.

Our bodies make vitamin D by converting cholesterol from the oil on our skin to vitamin D when the direct sun hits it.  How much sun is sufficient varies on our ability to synthesize vitamin D.  This depends on when we are out in the sun, our age, our latitude, our altitude, and our skin type.  For example, people with reddish hair and fair skin make vitamin D more efficiently so need very little time out in the sun—as little as 10 minutes.  Darker skin people can need 5-10 times that amount.  Skin exposure means uncovered arms and legs (face and hands is not sufficient) with no sunscreen.  In fact, sunscreen can block the rays responsible for making Vitamin D whiles still letting in damaging rays.  Regardless of how much sun you get, you cannot make too much vitamin D since once you've made enough, your body stops producing it.  So the balance that needs to be made is staying in the sun long enough to produce this essential vitamin and not getting too much sun exposure to risk skin cancer and cell damage that leads to wrinkles.  Even then, the risk of melanoma is not as clear as earlier feared.  Recent studies have questioned the sun, melanoma link.  There may even be an increased risk of melanoma if sun exposure is completely avoided. 

Despite reading the research, I have fair skin and red hair and have been inundated for decades with the message to keep out of the sun.  So I asked Mazin Al-Khafaji, one of the leading dermatology experts in Chinese medicine, about whether sun exposure is acceptable.  He said that the key to safe exposure is to avoid burning.  It is sun burning that is implicated in skin cancer and premature ageing of the skin.

Burning not only damages skin, but it can also prevent your absorption of vitamin D.  Interestingly, because the conversion of vitamin D occurs in the cutaneous oils of the skin, you should avoid showering or dipping in the pool for an hour after sun exposure to allow your body to absorb the vitamin D into the body.

Those of us living North of the 37th parallel (which runs through Southern Italy and Spain) have an additional challenge.  We do not get enough daylight throughout the year to synthesize enough vitamin D.  In the UK, we only get about 6 months of sufficient Vitamin D producing sun and recent studies have shown ½ of the population is Vitamin D deficient.  Being that we can only store enough for one to two weeks, sunbathing in the summer cannot carry you through the winter.  If you are brave and get out in the sun in the winter for sufficient time with legs and arms uncovered, you might be able to generate enough for a few days.  For those of us who do not enjoy the cold, luckily another source of Vitamin D is through food supplementation.  The highest ranked food supplement for Vitamin D is cod liver oil with herring, salmon, and trout following closely behind.  Vegans should seek out fortified foods if not getting sufficient sunlight. 

The conclusion is simple; enjoy a little sun with legs and arms exposed and no sunscreen.  If you are concerned about wrinkles, wear a hat and let your arms and legs do the work of making Vitamin D.  DO NOT burn.  Once you can see your skin begins to turn pink, cover up immediately with clothes.  You will find that day by day your skin will be able to tolerate more.  In the winter, consume food supplements if you do not enjoy cold exposure. 

By Liz Evans

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References:

www.medicinenet.com/script/main/art.asp

blog.nutritiondata.com/ndblog/2008/07/can-you-store-u.html

content.nejm.org/cgi/content/abstract/337/10/670

jcem.endojournals.org/cgi/content/abstract/64/6/1165

jcem.endojournals.org/cgi/content/abstract/95/4/1595

www.ajcn.org/cgi/content/abstract/85/6/1586

www.patient.co.uk/health/Vitamin-D-Deficiency.htm

www3.interscience.wiley.com/journal/118938441/abstract