US study: Dietary supplements risk – excessive minerals intake

Posted by AFN Staff Writers on 12th October 2011

A study published this week in The Archives of Internal Medicine has found that high levels of mineral intake in dietary supplements may not be a good thing.

Researchers from the University of Eastern Finland and the University of Minnesota, in the US, assessed the use of vitamin and mineral supplements 38,772 women in the longitudinal Iowa Women’s Health Study. The women had an average age of 62. Supplement use was self-reported in 1986, 1997, and 2004.

The researchers found that those women who took dietary supplements tended already to have higher mineral intakes from their regular food sources in their diet, compared with those who did not take dietary supplements. The researchers said that because of this, such mineral-fortified supplements could easily contribute to excessive intake of calcium, iron, zinc, and magnesium. This could result in serious health problems, and even premature deaths.

Commenting on the latest findings, Founding Director of the Asia Pacific Health and Nutrition Centre at Monash University, Emeritus Professor Mark Wahlqvist said, “The Iowa Women’s Health Study reporting on dietary supplements adds to growing concern about the safety of their use in Western society – usually more so, curiously, among the more socio-economically advantaged. Such people might be expected to out-perform the less advantaged, and indeed they do, unless they have unhealthy behaviours. It now seems that dietary supplementation is an unhealthy behaviour. The problem is partly that the people who use them are the ones who need them least.”

Professor Wahlqvist said that optimal nutrient intake from food came from having a diet which is diverse. He said that this was consistent with recent studies published on the Mediterranean diet in various locations, and a recent one (in which Professor Wahlqvist was a co-author) about the diets of people of Chinese ancestry and food culture in Taiwan.