Excess vitamins risky for women

Researchers from the University of Minnesota in the US examined data from more than 38,000 women taking part a health study that started in 1986.

The researchers collected data on the participants’, who were aged 62 years when the study began, supplement use in 1986, 1997 and 2004.

After adjusting for factors including the women’s age and calorie intake, the researchers found that those who took supplements had on average a 2.4 per cent increased risk of dying over the course of the 19-year study, compared to women who didn’t take supplements.

“Our study as well as other similar studies have provided very little evidence that commonly used dietary supplements would help to prevent chronic diseases,” study author Jaakko Mursu was quoted as saying by LiveScience.

“We would advise people to reconsider whether they need to use supplements, and put more emphasis on a healthy diet instead,” said Mursu, an epidemiologist at the University of Minnesota School of Public Health.

The new study, published in the ‘Archives of Internal Medicine’, linked a number of individual vitamins and minerals to the slight mortality risk, including multivitamins, vitamin B6, folic acid, iron, magnesium, zinc and copper.

For example, of the 12,769 women in the study who took a daily multivitamin, 40.8 per cent had died by the end of 2008, whereas 39.8 per cent of the 10,161 women who hadn’t taken a daily multivitamin had died.

However, Mursu said that the design of the study did not allow the researchers to determine if there was a specific cause for the increased mortality.  The increased risk of dying could be related to generally high concentration of compounds that the supplements contain, Mursu said.

On the other hand, taking calcium supplements seemed to lower the women’s death risk slightly by 3.8 per cent, found the researchers, although there was no relationship between consuming increasingly higher amounts of calcium and a continuing decrease in mortality rate.

While vitamins and minerals are necessary for proper nutrition, excess intake has not shown further benefit, and recent studies have cast some doubt on the idea that vitamin supplements provide a “safety net” for people not getting enough of a given nutrient. Instead, too much may be a problem, the researchers added.