Thoughts on the vitamin D craze
I suppose the word “craze” sums up my feelings nicely. To elaborate, though, I have some concerns about widespread recommendations that many or most people should consider taking large doses of supplemental vitamin D over long periods of time.
When I’m thinking about supplements my first question usually involves how this nutrient shows up naturally. I think of vitamins and minerals as isolated constituents of foods, and like many constituents they often act very differently in isolation. We normally absorb vitamin D through our skin when exposed to sunlight, and I assume this is for good reason. How does oral supplementation differ? What is lost when we take vitamin D this way? I’m not saying that supplementary vitamin D isn’t useful – I’d just like to know a bit more before I recommend long-term high doses for my clients.
Alan Gaby’s article entitled “Vitamin D: Irrational Exuberance?” found here sums up some of my concerns quite nicely, with a generous helping of science to back him up. Please check it out if you’ve been wondering about this as well.