Be aware that high-dose oral iron pills can sometimes damage the lining of the stomach and cause bleeding -- which can actually worsen anemia. Learn about recently reported cases, and what formulation of iron may reduce this risk, in the Concerns and Cautions section of our Iron Supplements Review.
Some supplements contain red iron oxide as a colorant. Should people at risk for iron overload be concerned about the iron provided by this ingredient? Find out in the Concerns and Cautions section of our Iron Supplements Review.
The urge to chew on ice, or consume or smell unusual substances, can be a sign of iron deficiency, as highlighted by a recently reported case. Get the details and learn about other symptoms of iron deficiency, in the What It Does section of our Iron Supplements Review. Also see our Top Picks among iron supplements.
Those taking calcium supplements had a 3.8% reduced risk of death. The calcium benefit ended, however, when taking more than 900 mg per day from supplements. It's worth noting that experts suggest many older women who take calcium supplements may not need to -- see the Calcium Supplement Review for more.
The mineral most strongly associated with an increased risk of death was iron, which showed a risk increase of 3.9% -- and the risk increased as the dose increased, particularly over 50 mg per day. However, the study grouped dosages of under 50 mg together, making it hard to determine the risk of low dosages of iron, such as those in many multivitamins. However, there is very little reason why a postmenopausal woman should be taking iron -- see the Iron Supplement Review for more.
Although not as statistically meaningful, other supplements were associated with the following increases in the risk of death during the study: multivitamins (2.4%), vitamin B6 (4.1%), folic acid (5.9%), magnesium (3.6%), zinc (3.0%), and copper (18.0%). An abstract of the study is online.
The bottom line: Don't take a supplement you don't need. If you want to know how much of each vitamin and mineral you need from your total diet and how much is too much, see our chart at www.consumerlab.com/rdas/.