The value of vitamin and mineral supplements for preventing or delaying the progress of chronic diseases is called into question by three new investigations.
Published in the Annals of Internal Medicine, the research is summarized in an accompanying editorial that concludes, “Most supplements do not prevent chronic disease or death, their use is not justified, and they should be avoided.”
One group of researchers systematically reviewed 27 existing trials, including more than 400,000 participants, that analyzed multivitamin supplements and single or paired vitamins. The analysis reported no clear benefit from supplements on all-cause mortality, cardiovascular disease or cancer.
A second analysis concluded that long-term use of a daily multivitamin did not provide cognitive benefits in male physicians aged 65 years or older. This research included 12 years of follow-up examining cognitive performance among 5,947 men who participated in the Physicians’ Health Study II.
The third evaluation concluded that high-dose oral multivitamins and minerals did not reduce cardiovascular events in patients after myocardial infarction.
“After a median follow-up of 4.6 years, there was no significant difference in recurrent cardiovascular events with multivitamins compared with placebo,” wrote the researchers of an accompanying editorial.
The editorial also describes a contradiction between evolving evidence about vitamin and mineral supplements vs. trends in consumption.
“Sales of multivitamins and other supplements have not been affected by major studies with null results,” the editorial said. “And the U.S. supplement industry continues to grow, reaching $28 billion in annual sales in 2010.”
Only Vitamin D, according to the editorial, is “an open area of investigation, particularly in deficient persons.”