Vitamin D - more of the same

Every now and then I check Google News for the latest findings on the sunshine vitamin. Here are some of the latest (past week):

- Vitamin D Deficiency Tied to ESRD in Blacks
- Vitamin D might lessen your flu risk
- Fight Off Back Aches & Pains This Winter With Extra Vitamin D
- Low Vitamin D Tied to Heart, Stroke Deaths- Low vitamin D linked to higher risk of breast cancer
- Vitamin D 'may cut premature birth risk and protect newborn babies'

And from the Scientific American, 'scientists found that the lower the subjects’ vitamin D levels, the more negatively impacted was their perform­ance on a battery of mental tests. Compared with people with optimum vitamin D levels, those in the lowest quartile were more than twice as likely to be cognitively impaired.

Now here's the thing. It is highly probable that in many instances low vitamin D could simply be a marker of poor health versus actually being a causal factor, and in all these cases correcting one's vitamin D level would offer little to no direct benefit. However, there is quite a bit of (mounting) evidence favouring vitamin D supplementation and very little downside, and for now at least that makes supplementation a very good trade.