Vitamin D- Coming to the Foreground of Research Again

In its latest appearance in the news, Vitamin D supplementation was correlated to some amazing results in cancer prevention. A small study published in the American Journal of Clinical Nutrition on June 8th showed that Vitamin D supplementation appeared to reduce the risk of certain types of cancer by 60-77%.

The researchers were following 1,179 seemingly healthy women with an average age of 67. The women were divided into 3 groups: 446 got calcium and vitamin D3, a similar number got just calcium, and 288 took a placebo. The study was originally looking to examine the effect of calcium and vitamin D on bone density, not cancer. For this reason, some critics are down playing the positive outcome.

The participants receiving the Vitamin D were given 1000 international units of Vitamin D3 (also known as Cholecalciferol) daily. The current daily recommendation for vitamin D is 200-600IU daily depending on age. Many scientists and researchers have been speculating that this level is far too low and this study helps to validate their claims. For more background and information about the widespread vitamin D deficiency in our country and why the current recommendations are far too low read my previous blog entry Vitamin D: The D is for Deficiency.

Despite the fact this was a study designed to examine bone health, the researchers could not ignore the overwhelming data correlating vitamin D supplementation to reduced risks of cancer. Only 13 women of the 446 (3%) that were given calcium and vitamin D developed cancer over a four year period. In contrast, 20 women out of the 288 given placebo (7%) developed cancer in that same 4 year period. This correlates to a 57% lower cancer risk in the group taking calcium and vitamin D. What is even more impressive is that when the researchers excluded first-year cancers – the ones most likely present before the study began – the results jumped to a 77% lower risk of developing cancer in the calcium/vitamin D group!

The calcium only group also showed a 43% lower risk of cancer when compared to the placebo group. However, when first-year cancers were excluded it did no better than the placebo group, indicating that calcium alone had little effect on lowering cancer risk.

In light of this and previous research about the safety and importance of vitamin D, many doctors and researchers are suggesting the guidelines for vitamin D consumption be changed. Dr. Michael Holick, who sat on the professional panel that issued the current guidelines for vitamin D in 1997 quoted as saying that this study shows that enough vitamin D “markedly reduces the risk of developing the most serious deadly cancers”. He supported raising the recommendation to 1000IU/day of vitamin D3 for the average individual.

It is of vital importance that people make the distinction as to what type of vitamin D they are taking. Many multi-vitamins will use a much weaker form of vitamin D referred to as, D2 (ergocalciferol). All the beneficial results found in the research pertaining to vitamin D supplementation have been done on the D3 form (Cholecalciferol). The average consumer must check the product labels of supplements to make sure they are getting the right one. If the label does not clearly specify what form of vitamin D is in the supplement it is advisable to not purchase it or to call the manufacture to find out.

Some food sources are rich in vitamin D3, including certain fish like salmon and tuna as well as eggs. Cod Liver Oil is a rich source and is a great way boost D3 intake while also getting the benefits of omega 3 fatty acids. Vitamin D3 can also be commonly found as an individual supplement.

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