Vitamin D is a Steroid vitamin. This means that it is “fat soluble” and that it does not really dissolve in water.
Therefore, to absorb Vitamin D, you would be well advised to have it during the highest fat content meal of the day – usually supper. Having your Vitamin D Supplement with the “fattiest” meal of the day will increase your absorption of the Vitamin by as much as 50%!
There are 5 forms of Vitamin D: D1, D2, D3, D4 and D5. Only D2 and D3 really matter to humans. It is almost impossible to get Vitamin D “naturally” from your diet. Your body has to make it – and to “activate” Vitamin D, it has to be exposed to sunlight in your skin.
Your skin make enough Vitamin D for the day after about 15 minutes of sunlight exposure. People with darkly pigmented skin need more sunlight exposure to generate the same amount of Vitamin D. This may be one reason that folks with darker skin have an increased incidence of prostate cancer.
It has been shown in the literature that moderate to high levels of vitamin D intake can reduce the risk of heart attacks – although the jury is still out on this one because it is difficult to test across the spectrum of cultures and environments in which we all live.
Observational studies have revealed that low Vitamin D levels are associated with Multiple Sclerosis, Cardiovascular Disease, Certain Cancers, Juvenile Diabetes, Parkinson’s Disease, Depression and Alzheimer’s Disease. So far, however, adequate scientific studies have not proven that taking Vitamin D Supplements can reduce the risks of developing these conditions.
It has also recently been found that good levels of Vitamin D in the blood at the start of a weight loss program, is predictive of weight loss success.
So what are we to do?
We have to stick with what we know. we DO KNOW that low Vitamin D levels are associated with those conditions above. Therefore, it would appear to follow that having a “normal” or “acceptable” Vitamin D level would remove you from at least one association with those diseases.
We also know that taking up to 1000-2000 IU per day of Vitamin D poses no risks or concerns to your health. So – while we are waiting for proper scientific studies to solve these questions – it seems reasonable to take Vitamin D to supplement our often inadequate serum levels of this Vitamin.
More information about Vitamin D:
At Boston University, after people with high blood pressure were exposed to UVA and UVB rays for three months, their vitamin D levels increased by more than 100% — and more impressively, their high blood pressure normalized. One theory about how vitamin D reduces blood pressure: It decreases the production of a hormone called renin, which is believed to play a role in hypertension.
In a study published in the Journal of the American Medical Association in December 2003, of more than 3,000 veterans (ages 50 to 75) at 13 Veterans Affairs medical centers, those who consumed more than 645 IU of vitamin D a day along with more than 4 grams per day of cereal fiber had a 40% reduction in their risk of developing precancerous colon polyps.
In a report in the Journal of the American Geriatrics Society in February 2004, researchers at the University of Basel in Switzerland showed that elderly women who took a vitamin D supplement plus calcium for three months reduced their risk of falling by 49% compared with consuming calcium alone. Those women who had fallen repeatedly in the past seemed to gain the most benefit from vitamin D.
A study published in the Jan. 13, 2004 issue of Neurology indicated that women who get at least 400 international units of Vitamin D are 40% less likely to develop multiple sclerosis compared with those not taking over-the-counter supplements.
The research is ongoing – and it will be interesting to see where it takes us. Clearly nothing in terms of how Vitamin D is used by our bodies is simple – but in the mean time we have to stick with what we know: Vitamin D is potentially really good for us, and doses in the 1000 – 2000 IU per day range are totally harmless.