Older women who take vitamin supplements to combat or prevent chronic illnesses suffered from increased mortality rates compared to those who didn’t, according to a recent
JAMA Internal Medicine study.
“Supplemental nutrient intake clearly is beneficial in deficiency conditions. However, in well-nourished populations, supplements often are intended to yield benefit by preventing chronic diseases,” the study says.
JAMA’s study, which looked at self-reported data from nearly 40,000 Iowa women with an average age of 62, found that taking dietary supplements of certain vitamins and minerals as “insurance” for better health rather than to correct a deficiency was associated with slightly higher death rates.
Women who took multivitamins saw a 2.4% increased mortality risk, which was dwarfed by the risk for those who took iron (3.9%), vitamin B6 (4.1%), folic acid (5.9%) and copper (18%). Taking calcium supplements, however, lessened one’s risk by 3.8%.
The data was collected in 1986, 1997 and 2004 with about 40% of participants having died by the end of 2008, the study says.
“In the United States, the use of dietary supplements has increased substantially during the past several decades, reaching approximately one-half of adults in 2000,” researchers wrote in their conclusion. “Sixty-six percent of women [participants] used at least one dietary supplement daily in 1986,” increasing to 85% in 2004.
Also, more than a quarter of the women used at least four supplements, according to the study’s 2004 data.
But there is more work, research to be done, researchers say, especially regarding the long-term effects of multivitamins and less-used vitamins such as iron.