A new US research suggests that women with at least a mild deficiency in the nutrient iodine could have impaired fertility.
The study, published in the journal Human Reproduction, included around 500 American women who were trying to get pregnant. Those with moderate-to-severe iodine deficiency were 46 percent less likely to get pregnant during each menstrual cycle than those with sufficient iodine levels, it concluded.
Even women with mildly deficient iodine levels had a slightly harder time getting pregnant, according to researchers led by Dr. James Mills of the US National Institute of Child Health and Human Development.
"Women who are thinking of becoming pregnant may need more iodine," said Mills, who conducted the study along with colleagues at the New York state Department of Health in Albany.
Iodine -- a mineral that helps regulate metabolism -- is found in seafood, iodized salt, dairy products, and some fruits and vegetables.
Women are advised to take prenatal vitamins, which include iodine, at least three months prior to conception.
The new research showed that iodine deficiency is common among US women. In the study, about 56 percent of the women had sufficient levels of iodine, nearly 22 percent were mildly deficient, about 21 percent were moderately deficient, and 1.7 percent were severely deficient.
Mills said, "Iodine requirements increase during pregnancy, and the fetus depends on this mineral to make thyroid hormone and to ensure normal brain development."