Vitamin D... From Sun or Supplements?

Today’s Healthy Living Section of the Dallas Morning News featured a story on healthy ways to make your face more beautiful, which included protecting your skin from the sun’s UV rays. As a guy that works at Cooper and oversees our vitamin and nutritional supplement line, I spend a great deal of time following the literature on this topic.

I obviously agree that the sun can do tremendous damage (aging and increased risk of skin cancer).   But I also I think it’s always important to remind folks that when it comes to sun screen you should be careful “not to throw the baby out with the bathwater.” That same UVB light that accelerates aging and increases cancer risk is also the same light that generates vitamin D.

We have a vitamin D deficiency epidemic in this country.  An article published in the 2009 Archives of Internal Medicine found that 77 percent of U.S. adults and adolescents were insufficient in vitamin D (90 percent of Mexican-Americans and 97 percent of all non-Hispanic blacks). At Cooper Clinic we have been measuring vitamin D levels in our patients since 2006, and we find approximately 80 percent of our first time patients have levels lower than we like to see (<40 ng/ml).

Dr. Ed Giovannucci, a highly respected researcher from Harvard, wrote in the Journal of the National Cancer Institute in 2006 that “sunlight might prevent 30 deaths for each one caused by skin cancer. I would challenge anyone to find an area or nutrient or any factor that has such consistent anti-cancer benefits as vitamin D.  The data are really quite remarkable.”

Of course, then the question comes up of whether physicians prefer that their patients get vitamin D through supplementation, as opposed to directly from the sun.  That really depends on whom, and what type of doctor, you ask.  Most of the research indicates that there is really very little difference between the two.

Most physicians feel supplements are the most logical choice because of ease, cost, accuracy of dosing, etc. Dermatologists clearly like to steer folks away from the sun.  However a few, including Dr. John Cannell, Founder of the Vitamin D Council, feel that the sun is the preferred method since that’s the way we were “designed” to get vitamin D.

Obviously no one, including Dr. Cannell, recommends getting a sun burn, but for most folks 10-15 minutes of unprotected sun exposure seems to be a logical, and safe, dose. The problem is how often do most people go out in a bathing suit, or shorts and a tank top, between 10 a.m. and 2 p.m. when the UVB light is most available? Clearly if the weather is gloomy and overcast that wouldn’t be practical.

Something else to keep in mind is that there is a huge variability in how much vitamin D we synthesize from the sun, or absorb from supplements. There clearly is no such thing as “one size fits all.” Cooper Clinic physicians recommend starting with 2000 international units (IU) of vitamin D-3 per day and go up in dose as needed. The ideal method to determine how much vitamin D you need is to get a blood test. But from a practical standpoint, most people aren’t going to take the time or spend the money to do that. 2000 IU per day may not get them to an “optimal” blood level, but for most individuals it will at least help them avoid “deficiency” (less than 20 ng/ml).

Even though I run and ride my bike outside quite a bit, I have found that I need to take 5000 IU of Vitamin D-3 per day for me to maintain a blood level of 60 ng/ml (my ideal target).  But remember, everyone is different.  The main takeaway is to make sure to get your vitamin D.  Whether it’s from the sun or supplements....just get it.