Dietary Supplements May Hold Health Risks for Women

A new study claims that women who take vitamins and other dietary supplements have a slightly higher risk of dying compared with women who do not.

Researchers from the University of Minnesota (Duluth, USA) and the University of Eastern Finland (Kuopio) examined data from nearly 39,000 women taking part in the Iowa Women's Health Study, an ongoing study of women who were around age 62 at its start in 1986. The researchers collected data on the women's supplement use in 1986, 1997, and 2004. Over 19 years of follow-up, 15,594 of the women died. Supplement use increased from 1986, when 63% of the women reported taking at least one supplement, to 85% in 2004.

The results showed that after adjusting for health and demographic factors, including the women's age and calorie intake, multivitamins, vitamin B6, folic acid, iron, magnesium, zinc, and copper were associated with an average 2.4% increased risk of death. The strongest association between a supplement and an increased risk of death was for iron; the more iron one took, the greater the risk, and as one aged, it took less iron to increase the risk of dying. On the positive side, calcium supplements seemed to reduce risk of death. The study was published in the October 10, 2011, issue of Archives of Internal Medicine.

“The increased chance of dying could be related to generally high concentration of compounds that these supplements contain,” said lead author Jaakko Mursu, PhD, a nutritional epidemiologist at the University of Eastern Finland. “Most supplements contain higher amounts of nutrients than would be derived from food, and it is known that several compounds can be toxic in higher amounts, especially when consumed for a long time, as some of these accumulate to body.”

“Our study raises concerns about the safety of a number of commonly used dietary supplements,” added Dr. Mursu. “We would advise people to reconsider whether they need to use supplements and put more emphasis on a healthy diet.”

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University of Minnesota
University of Eastern Finland