[doublekill]

I just did. The research is divided into two: those that look at clinical outcomes (such as cardiac arrest) do not find that vitamins help. Those that look at quality of life indicators, recovery, infection severity, and muscle strength do find significant improvements of supplementation.

And they find no harm of normal use, but warn against dangerous toxicity effects of overdosing.

[arcticbull]

Without any regulation how do you know how effective your particular multivitamin is at making bioavailable any given vitamin or mineral, re: the study I posted showing a range of 19% to over 90% for magnesium? It's pretty much impossible to know if they do anything at all. Which brings me back to my point: if you have a specific issue, a specific supplement whose effectiveness if validated is likely way cheaper and much more effective -- otherwise, the advice I would give anyone is to eat their greens and stop fretting.