In an editorial about the effect of vitamin-mineral supplements in the prestigious American Journal of Clnicial Nutrition, the author, Donald McCormick, a professor of nutrition at Emory University, writes:
This study is a meta-analysis of randomized controlled trials that were previously reported. Of 2311 trials identified, only 16 met the inclusion criteria.
That’s throwing away a lot of data! Maybe, just maybe, something could be learned from other 2295 randomized controlled trials?