Tuesday, May 25, 2010

Vitamin D: Should you soak up the sun to get this vital nutrient?

Yesterday we discussed UVA sun rays and the aging effects they cause. Though UVA can also be responsible for skin cancer, UVB is the part of sunlight primarily responsible. (Think UVA, “A” for “aging”; UVB, “B” for “bad.”)

However, UVB light, which is the more dangerous of the two, is also the part of sunlight that causes the body to produce vitamin D – a necessary nutrient. Recent medical news has stressed that up to half of the U.S. population could be vitamin D deficient, and the FDA is considering increasing its daily recommendation of 400 International Units (IUs) of vitamin D to 800 IUs. Healthy levels of vitamin D have been linked to a decreased risk for osteoporosis, high blood pressure, cancer and certain autoimmune diseases.

While vitamin D occurs in foods such as fish and fortified dairy products, your body produces vitamin D naturally when you skin is exposed to sunlight. In fact, just 20 minutes of full body exposure will produce 10,000 International Units of vitamin D. (After about 20 minutes, your body creates a chemical response so you can’t produce too much vitamin D.) If you wear sunscreen (recommended to reduce your risk for skin cancer), the UVB rays will be blocked and your body will NOT produce vitamin D. So should you forego sunscreen so that you can get your vitamin D?

In a May 19th lunch and learn at the Alvin and Lois Lapidus Cancer Institute, Sean T. Gunning, M.D., said that he believes that the jury is still out on the health benefits of vitamin D. While there is a correlation of people who have higher levels of vitamin D in their systems and a lower risk for certain diseases, it doesn’t mean that their health is due to the vitamin D.

Healthy people tend to exercise outside, make better dietary choices and take vitamin supplements – all of which can lead to higher levels of vitamin D. Therefore these people may test higher for vitamin D simply because of their choices that make them healthy also give them more vitamin D; their health is a byproduct of their lifestyle, not necessarily because of their high levels of vitamin D.

As for getting the recommended daily amount of vitamin D, so far there’s no evidence that the vitamin D produced from being out in the sun is superior to the vitamin D we can get from vitamin supplements. The 400 (and even 800) IUs recommended by the FDA is an amount that can be easily obtained through a multi-vitamin, making it unnecessary to expose your skin to the sun.
-Holly Hosler

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