What's the best source of vitamin D?
By Dr. Jonathan Wright on 10/11/2010

Question: I know from your newsletter and from the e-Tips that vitamin D is really important. And I also know it's in milk -- but you say we shouldn't drink milk. So what's the best way to boost my vitamin D intake?

Dr. Wright: The food industry began adding vitamin D to milk years ago. It was a cheap way to "protect" the public from deficiency. Unfortunately, it's just not working: Cases of vitamin D deficiency have been skyrocketing over the past several years. Besides, there are so many health problems linked to cow's milk that, as you've read, it's the last thing I'd recommend anyway.

Especially when the best source of vitamin D is even more widely available -- not to mention cheaper. Certain wavelengths of sunlight (found in ultraviolet B, or UVB, rays) act on a cholesterol derivative in human skin, starting a chain of reactions, which ultimately produce vitamin D. So if it were possible for you to get enough sun, you wouldn't have to worry about vitamin D.

The problem is, hardly anyone does get enough sun these days, which is why supplements are so important. I recommend 4,000 IU ("International Units") daily for adults and teenagers, 1,000 IU for infants and small children, and 2,000 IU for everyone in between.

About the author

Jonathan V. Wright, M.D. has degrees from both Harvard University (cum laude) and the University of Michigan. More than any other doctor, he practically invented the modern science of applied nutritional biochemistry and he has advanced nutritional medicine for nearly three decades.