Vitamin D – What are the health implications?

But starting in the 80s we started learning about the relationship of a low vitamin D status and the risk of cancer—colon cancer, breast, prostate, ovarian. There are 17 different types of cancer that are associated with low vitamin D status. Dr. Cedric Garland and his group at UC San Diego have done a lot of research especially with colon cancer and breast cancer.

Vitamin D and immunity

You look at immunity, and this is the one that I think is fascinating. Those with the lowest levels of vitamin D are 36 percent more likely to suffer from colds and flu and upper respiratory tract infection. If you get sick a lot, it may have something to do with your vitamin D status.

Vitamin D – inflammation and cognition

We know it is related to chronic pain because vitamin D is anti-inflammatory. If you have joint issues and you are just achy all the time (low vitamin D may be the reason). It’s related now to depression and cognitive issues. So again, we have receptor cells all over the body and we have been making it for a long, long time—a couple of million years—and the problem is that we live inside, we work inside and if we go outside we wear sunscreen. Which is not a bad idea—no one wants to increase the risk of skin cancer but you don’t want to throw the baby out of the bath water and a sunscreen with SPF of 15 or greater and I don’t think anybody wears 15 anymore—it’s always 50 or 100—that will block 99 percent of vitamin D synthesis.

So if you are wearing sunscreen you are not making any vitamin D. You may be lowering your risk of skin cancer which is terrific. But again you don’t want to throw the baby out with the bath water. You have to be proactive with your health and figure where your D level is and then be it through the sun or through supplements—supplements are very easy and very inexpensive— just make sure you take care of yourself.

If you are a lifeguard in La Jolla, California, you probably have a pretty good natural vitamin D level or if you’re a mailman and you’re  outside all the time probably you do. But all the data indicates that even if you sail a lot or you ride your bike a lot you are outside a lot. In fact, we did a study back in 2009, I was curious about runners. I am involved with the Dallas marathon, and I thought, runners are outside a lot and I wondered if they have higher vitamin D levels than normal. We looked at 36—just an observational study—we looked at 36 men and women that were averaging at least 20 miles a week of running and 75 percent of them had vitamin D levels below 40 which is kind of the cut point at the Cooper Clinic of where we want people to be. So, even if you are an athlete, a tri-athlete, a runner or whatever, the odds are you are going to be low and we also know that skeletal muscle has two vitamin D receptor sites, so if you are an athlete you want to make sure that you get vitamin D where it should be.