|The IOM's Report on Vitamin D and Calcium|
How much D do we need?
After reviewing all available scientific research, the IOM recommends 600 IUs of Vitamin D per day for the vast majority of people. 800 IUs is recommended if you're over 70.
This is far more than previously recommended (200 IU per day). But it falls short of the 800 - 2000 IU/day that many medical experts and other medical societies have touted.
Many of us have been reading study after study supporting the benefits of Vitamin D for a wide range of ailments. We've also read numerous reports revealing widespread Vitamin D deficiency or insufficiency even in healthy young adults. But when the IOM summed up all the positive and negative studies they concluded that there is only strong evidence that Vitamin D benefits bone health. Too little or inconclusive data exists for all the other potential benefits (heart disease, cancer, depression, etc.), they said.
While cautiously optimistic about the role of Vitamin D in overall health, the IOM took a very conservative approach to recommending more supplementation. The past few decades have seen many examples of mega dose supplements of vitamins - beta carotene and vitamin E among them - causing more harm than good. Basically, they don't want to jump to a premature conclusion on "more being better" and get burned. There's some wisdom in that.
More Research is Needed
Apparently it's impossible to write a consensus statement without printing these words. The Vitamin D story is far from over...and it will take many more years for the full truth to emerge. So we'll have to keep our eyes peeled for more research to clarify whether supplemental Vitamin D benefits more than just our bones, and to what degree.
How To Get At Least 600 IUs
Remember, Vitamin D is the sunshine vitamin - our skin makes it naturally when exposed to bright sunshine. But alas, most of us live our lives in the shade (staring at a computer, for example), we wear sunscreen to prevent skin cancer, and we have a strange affinity for winter lands. So a dietary or supplemental source is typically needed.
A Winter Vegan Vitamin D Sandwich
A multivitamin usually has about 200-400 IUs of vitamin D. A cup of fortified soymilk has about 120 IU. Most "natural" vegan cereals do not contain added vitamin D, but some might have 100-200 IU.
In other words, it's fairly likely that in winter you will need a vitamin D supplement. Since Vitamin D is fat soluble (meaning you can store some of what you don't use), I take 1000 IU every second day (or when I remember)!
You can find the IOM report here.