Saturday, February 27, 2010
Do You Get Enough "Vitamin D"?
Yes, I have posted about vitamin D before. I will probably do it again, too. And again. That's because it is estimated that 77% of the US population suffers from vitamin D deficiency and it's something we can actually do something about!
So what? You think you get enough from sunshine and milk and are excluded from the list of those who are deficient? Nah, you are probably not. Researchers are beginning to understand (and prove) the RDA (400 IU/day for adults) for vitamin D is not nearly high enough. In fact, the NIH (National Institutes of Health) previously set a safe upper limit of 2,000 IU/day and now acknowledges newer data supporting as much as 10,000 IU/day. The Institute of Medicine is revisiting vitamin D and calcium recommendations, with a report due out before the end of this summer, 2010.
Why be concerned? For starters, there are 17 different cancers (including breast and colon cancer) that are linked at least in part to this deficiency. Laboratory tests have shown that vitamin D can kill cancer cells. Diseases like high blood pressure, multiple sclerosis, strokes, Parkinson's, TB, asthma, cardiovascular disease, chronic pain and weakened immunity are also linked to a vitamin D deficiency. There's also a connection between the flu and low levels of D.
The current "adequate" RDA for vitamin D varies with age. While the RDA for the average adult is 400 IU, it goes up to 600 IU as we approach 70. Our diets usually provide about 100 IU/day, and even though commercial milk is "fortified" it doesn't make much of an addition.
Another factor is how your body absorbs this vitamin. Vitamin D is converted in the liver and kidneys to calcitriol, the active hormone form of vitamin D. Kidney or liver disease can affect this conversion. Additionally, as skin ages or becomes damaged, it is less able to synthesize D from sunlight. This information is important to me because (1) I'm a redhead who has always had skin damage (sunburn) and (2) I have some liver disease, from chemical exposure over the years.
Currently I take one capsule of 1,000 IU D-3 in the morning, and another at night. Based on current research I am going to increase those amounts slowly, and wait with anticipation for the latest study and recommendations to be released this summer.
Vitamin D supplements come in 2 forms, D-2 and D-3. Research suggests D-3 is more readily utilized by the body and many supplement manufacturers are switching to D-3. My doctor does blood work every few months to be sure I do not have too much Vitamin D in my bloodstream as high amounts can be toxic.
Please do not take what I am choosing to do for my self as medical advice, nor even a recommendation for you!
Update, November 2010: I now take about 5,000-6,000 IU daily of Vitamin D. 2,000 IU of that comes from a half-teaspoon of high vitamin butter oil combined with fermented cod liver oil taken in the morning; the remainder is spaced over lunch and dinner with D-3 tablets.