Synthetic vitamins versus whole food supplements like sea vegetables may do more damage than good, based on a new study that adds to a rising body of evidence suggesting some synthetic supplements may have health risks. Researchers from the University of Minnesota examined data from greater than 38,000 women taking part in the Iowa Women’s Health Study, a continuing study with 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.Women who took supplements had, on average, a 2.4 percent increased risk of dying during the 19-year study, in comparison to women who didn’t take supplements, after the investigators adjusted for factors including the women’s age and calorie intake. The new study 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 instance, of the 12,769 women in the study who took a daily multivitamin, 40.8 percent had died by the end of 2008, whereas 39.8 percent of the 10,161 women who hadn’t taken a daily multivitamin had died.
The elevated chance of dying may perhaps be related to generally high concentration of substances that these supplements contain. Most synthetic supplements contain higher amounts of nutrients than would be obtained from food, and it is known that a number of compounds can be toxic in higher amounts, most importantly when consumed for a long time, as some of these accumulate in the body. Consuming calcium supplements, on the other hand, actually seemed to lower the women’s death risk slightly, by 3.8 percent, although the researchers noted that there was not a relationship between consuming increasingly higher amounts of calcium and a continuing decrease in mortality rate.