[ibigb]

For a review of many vitamin D studies google "site:theincidentaleconomist.com vitamin d", a blog by a doctor who evaluates many studies. Many do not show extra vitamin D beneficial.

Blog quoute: " The IOM says that anything over 20 ng/mL is “Generally considered adequate for bone and overall health in healthy individuals” and when you get over 50 ng/mL “Emerging evidence links potential adverse effects to such high levels”. I do not understand why we keep looking for Vitamin D to be some sort of wonder drug. It’s seriously baffling to me."

So we need some,>20ng/ml but keep it under 50 ng/ml.

[wtetzner]

I suspect it's less that Vitamin D is a wonder drug, and more that the majority of the population (at least in the US) has a Vitamin D deficiency.