Women's Health: Iron May Be the Answer for Some Infertile Women
Could infertility be reversed by taking a simple supplement? Maybe, in some cases. A study released today from the November issue of Obstetrics and Gynecology found that infertile women who consumed an average of 76 milligrams of iron per day through supplements and food sources had a 60 percent lower risk of failure to ovulate than those who ingested the lowest amounts of iron. Failure to ovulate is the second leading cause of infertility, after clogged fallopian tubes.
The study examined data provided by more than 18,000 nurses participating in the Nurses' Health Study, zeroing in on 438 who reported having ovulation problems. Those who ate the most "free" iron (found in supplements, fortified foods, legumes, and grains) had the greatest protection against infertility. The researchers controlled for age, smoking, obesity, physical activity, and previous use of oral contraceptives, all of which can affect infertility.
Interestingly, the study found that the benefits didn't apply to women who got most of their iron from animal sources like red meat and pork. In fact, women who ate the largest amount of so-called "heme" iron–equivalent to four or five weekly servings of red meat–experienced no drop in infertility risk even if they also took in ample amounts of free iron. "These were very striking differences, suggesting that women should focus on getting their iron from supplements and fortified foods," says study leader Jorge Chavarro, a research fellow in the department of nutrition at the Harvard School of Public Health in Boston.
The study examined iron as a factor in ovulation because the ovaries, unlike most other organs, produce key proteins involved in iron binding and transport to cells. "It could be that iron is important for the maturation of the egg," Chavarro explains, though he doesn't know why heme and free iron would have different effects on the ovary.
More than 20 percent of young women have depleted iron levels, according to recent population surveys. Women planning to become pregnant should consider taking a supplement about three months before conceiving to give their bodies a chance to build up iron stores, recommends Chavarro. A prenatal supplement containing iron, folic acid (to prevent neural tube defects), and other micronutrients may be the optimal choice, he says, adding that the supplement should contain at least 40 milligrams of iron to ensure maximum benefits.