Increased iron intake may enhance female fertility, says a recent study from the Harvard School of Public Health (Obstetrics and Gynecology, 2006, vol. 108, no. 5). Researchers evaluated more than 18,500 married, premenopausal women with no history of infertility who became or attempted to become pregnant between 1991 and 1999. During eight years of follow-up, scientists found that women who took supplements with 41 mg or more of vegetarian-source nonheme iron had a 62 percent lower risk of infertility than those who consumed little of the nutrient or heme iron from animal sources. Overall, women taking the highest levels of nonheme iron showed the least risk of infertility.