In the post “Let The Sunshine In” we looked at the recent dustup over vitamin D. Vitamin D, more hormone than vitamin, is more crucial to health than previously appreciated. As promised, in this post we review the book, The Vitamin D Solution by scientist Michael F. Holick, PhD, MD. (Another good book is The Vitamin D Cure, by James E. Dowd, MD.)
Two key questions remain unsettled by science and Dr. Holick gives his input:
• What is the optimum blood level of vitamin D? Dr. Holick recommends staying above 30 ng/mL; the Institute of Medicine (IOM), more cautious, used 20 ng/mL in their report. This is a big deal: the IOM, using “20”, didn’t see a big vitamin D deficiency in America. If you use Holick’s “30”, there is a widespread deficiency. Others use higher targets, up to 50 ng/mL. Take your pick.
• What is the best way to get vitamin D (pills or sunshine)? Dr. Holick and Dr. Dowd put more emphasis on sunshine, but suggest complementing with pills as needed, especially in northern latitudes. Food contributes vitamin D also. The vitamin D from sunshine lasts twice as long in your blood according to Holick, and there are 5-10 other molecules also produced by the skin which science is just beginning to study.
The importance of vitamin D is shown by the diseases it can prevent or help cure, according to Dr. Holick. The cause of these diseases is not fully understood, thus not all agree with Dr. Holick. Because the broad role of vitamin D is a more recent discovery, the passage of time should fill in some of the blanks. Right now, vitamin D looks like a wonder drug; it just might be but we should be careful not to go overboard. In the meantime we all must decide how to protect our families and ourselves. Below is a partial list of diseases helped by vitamin D:
• Cancer: breast, prostate, colorectal, ovarian, and pancreatic cancer risk can be reduced up to 30-50% by maintaining your vitamin D, which helps regulate cell growth. Dr. William B. Grant, a vitamin D researcher, has projected 155,000 less internal cancers each year if people get adequate (vitamin D-producing) sunshine.
• Heart disease: you can reduce your risk of high blood pressure, heart attack or stroke by up to 50%.
• Fertility: adequate vitamin D improves fertility, reduces risk of C-section, shortens labor, and makes for a healthier baby.
• Osteoporosis: the essential role of vitamin D is well known.
• Autoimmune disease: vitamin D reduces your risk of rheumatoid arthritis, or multiple sclerosis, by up to 40%. Holick also proposes that the epidemic of fibromyalgia in some cases may actually be vitamin D deficiency.
• Depression: the active form of vitamin D stimulates production of serotonin, essential to good mood. (Is that why I enjoy the beach so much?)
• Insomnia: yes, sufficient vitamin D helps you sleep better also.
• Overweight: vitamin D is necessary for proper production of leptin, which regulates appetite so you don’t eat too much.
Finally, remember that most dermatologists caution against too much sunshine without noting that some is needed. I like the sunshine but try to avoid getting burned, or even “pink”. Holick must have a sense of humor for he told of a survey for vitamin D levels among dermatologists in Australia: 82% were vitamin D deficient! That will teach them. I saw my own dermatologist the other day and asked why I didn’t see her down at the beach last summer. She didn’t blink, said her baby was young and tries to eat the sand. She’s a great doctor.