Low iron intake is a problem worldwide

Iron deficiency is the world’s most common nutritional deficiency -- as much as two-thirds of the global population may not be getting enough iron, according to the World Health Organization. Among Americans, iron deficiency is much less common, though it’s a health risk faced by teen girls, pregnant or dieting women and endurance athletes. The essential mineral, which the body uses to make oxygencarrying red blood cells and to produce energy, is found in meats, fish, beans, leafy greens and fortified grains. Some forms (such as the iron found in meat and fish) are easier for the body to use than others (such as the iron in spinach).

*

Uses: Iron supplements are typically taken to treat iron-deficiency anemia (low red blood cell count), which can cause fatigue, weakness, shortness of breath and decreased immunity.

Dose: The Food and Drug Administration’s recommended daily allowance (RDA) for iron ranges from 8 to 18 milligrams per day for adults. Multivitamin products containing iron often supply 10 to 18 milligrams per daily dose.

Precautions: Consult a doctor before taking high-dose iron supplements, as too much iron can pose serious risks. Long-term, high-dose iron intake may lead to cirrhosis of the liver or heart disease -- particularly in adults with hemochromatosis, a genetic disorder that causes the body to overabsorb iron. Take iron supplements on an empty stomach, a few hours after meals and before going to bed. And avoid alcohol and antacids, both of which can reduce absorption. Iron-containing products are one of the top causes of accidental poisonings among small children -- even a few hundred milligrams can prove fatal.

Research: Studies have shown that increased iron intake during pregnancy decreases the likelihood of low birth weight infants and premature delivery. In children and teens with iron-deficiency anemia, supplements can relieve the depression and improve the social and learning disorders associated with the condition. Though some studies suggest that too much iron can increase the risk of heart disease -- in addition to diabetes, lupus, cancer and aggravated arthritis symptoms -- researchers say that more studies are needed to prove these links. There’s no good evidence that iron supplements will boost energy and exercise performance in people who are not deficient in the mineral.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective.

-- Elena Conis