Dietary supplements in older women: Less is better!

Certain dietary supplements associated with increased risk of death in older women

Consuming dietary supplements, including multivitamins, folic acid, iron and copper, among others, appears to be associated with an increased risk of death in older women, according to a report in the October 10 issue of Archives of Internal Medicine.

The use of dietary supplements in the United States has increased considerably over the last decade.

Jaakko Mursu, Ph.D., of the University of Eastern Finland, Kuopio, Finland, and the University of Minnesota, Minneapolis, and colleagues used data collected during the Iowa Women’s Health Study to examine the association between vitamin and mineral supplements and mortality (death) rate among 38,772 older women (average age 61.6 years). Supplement use was self-reported in 1986, 1997 and 2004 via questionnaires.

The authors found that many supplements appeared associated with increased mortality risk. After adjustment, use of multivitamins, vitamin B6, folic acid, iron, magnesium, zinc and copper, were all associated with increased risk of death in the study population. Conversely, calcium supplements appear to reduce risk of mortality. 

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The association between supplement intake and mortality risk was strongest with iron, and the authors found a dose-response relationship as increased risk of mortality was seen at progressively lower doses as women aged throughout the study.

“Based on existing evidence, we see little justification for the general and widespread use of dietary supplements,” the authors conclude. “We recommend that they be used with strong medically based cause, such as symptomatic nutrient deficiency disease.”

(Arch Intern Med. 2011;171[18]:1625-1633. Available pre-embargo to the media at www.jamamedia.org.)

 For more details visit: http://www.eurekalert.org/pub_releases/2011-10/jaaj-cds100611.php