Confused about Vitamin D? Notes from a San Francisco Bay Area Dermatologist

There is so much information circulating now on vitamin D, its benefits to your health and how one should go about obtaining it, that its no wonder people are confused.

Let’s start with why is vitamin D important to our health.  We have long known that vitamin D allows our bodies to absorb and use calcium, which is essential for healthy bones.  However, there are some recent studies that suggest it may also play a role in preventing certain cancers and diseases.  This information, combined with the fact that vitamin D levels appear lower among Americans today than 15 to 20 years ago (American Journal of Clinical Nutrition), have sparked the conversation on whether or not we are getting enough vitamin D for optimal health.

Some of the confusion is caused by the fact that vitamin D is produced by the skin following exposure to the sun’s UV rays (specifically UVB rays), yet we are consistently told to avoid the sun, tanning beds and to glob on sunscreen daily.

So, what is wrong with tanning or tanning beds to get our vitamin D?  As a dermatologist, I continue to recommend that my patients minimize their sun exposure, avoid tanning beds and always wear their sunscreen.  The potential risk for skin cancers and photo damage is too great to obtain your vitamin D through tanning.

Another argument against sun exposure for vitamin D is that the amount produced by the skin varies depending on time of day, season, latitude, age and skin pigmentation.  For example, UV exposure is unlikely to produce enough vitamin D in darker skin, so relying on the sun alone puts these skin types especially at risk for deficiency.  Also, the skin of the elderly has a reduced ability to produce vitamin D from sunlight.  Between November and February, UVB radiation is insufficient to produce adequate vitamin D for people living above 42 degrees north latitude, which includes Boston, northern California and other northern areas.

So how do we ensure we are getting enough vitamin D?  Diet and supplements remain the safest and most consistent way for people of all ages and skin types to get their Vitamin D.  Vitamin D can be found in fortified dairy products and cereals, orange juice, egg yolks, oily fish and dietary supplements.  Try to look for supplements containing vitamin D3, the form most easily absorbed by the body.

If you still feel that the sun is a good way to get your vitamin D,  it is important to realize that for lighter skin types, a few up to fifteen minutes of mid-day sun exposure on your forearms, a few times a week, would provide adequate vitamin D, so tanning will never be a safe or recommended option.

I support current recommendations from United States dermatology groups, which are 1,000 - 1500 IUs (international units) a day of vitamin D and 1000 mg of calcium for a healthy adult.  Check with your doctor to be sure this amount is appropriate for you.  This potential role of vitamin D and disease prevention is of great interest and I look forward to more information as further studies are conducted.

Tags: bay area dermatologist, san francisco dermatologist, skin cancer, sunscreen, tanning, tanning beds, uv rays, uvb, vitamin d

This entry was posted on Wednesday, August 5th, 2009 at 4:30 pm and is filed under Skin Health. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.