Vitamin pills are a waste of money?

People should stop wasting their money on dietary supplements, some physicians said recently in response to three large new studies that showed most multivitamin supplements were ineffective at reducing the risk of disease, and may even cause harm.

The new studies, in the journal Annals of Internal Medicine, including two new clinical trials and one large review of 27 past clinical trials conducted by the US. Preventive Services Task Force found no evidence that taking daily multivitamin and mineral supplements prevents or slows down the progress of cognitive decline or chronic diseases such as heart diseases or cancer.

The message is simple: Most supplements do not prevent chronic disease or death, their use is not justified and they should be avoided,” the physicians wrote in an editorial published along with the studies.

This message is especially aimed at people who have no signs of nutritional deficiency — meaning most supplement users in the United States, the researchers said.

“Study after study comes back negative — yet people continue to take supplements, now at record rates,” said Dr Edgar Miller, one of the five authors of the editorial and a professor of medicine and epidemiology at Johns Hopkins University in Baltimore.

There may be a psychological component to taking supplements, Miller said. Despite evidence showing supplements hold no benefit for the general population, some people may rationalise they need supplements because their diets lack necessary nutrients, Miller told LiveScience.

The new findings are in line with those of previously published studies that have found no benefits from dietary supplements, including B vitamins and antioxidants, and even suggested possible harms. Results of clinical trials involving tens of thousands of people have shown that beta-carotene, Vitamin E and possibly high doses of Vitamin A supplements actually increase death rates, the researchers said.

“We believe that the case is closed — supplementing the diet of well-nourished adults with most mineral or vitamin supplements has no clear benefit and might even be harmful,” the researchers wrote in their editorial.

The use of multivitamin and mineral supplements among Americans has increased to about 50 per cent in the mid-2000s, up from 40 per cent in the early 1990s, according to the Centers for Disease Control and Prevention.

For some supplements such as beta-carotene and Vitamin E, studies have found declines in use, following reports of their negative effects on lung cancer and mortality.

In contrast, sales of multivitamins and other supplements have not been affected by major studies that didn’t find benefits, the researchers said. The US supplement industry continues to grow, and reached $28 billion in annual sales in 2010. Similar trends have been reported in the United Kingdom and in other European countries.