Improving nutrition and reproductive health : the importance of micronutrient nutrition

The micronutrient status of women in developing countries affects their health during pregnancy and lactation, the outcomes of their pregnancies, and the health of their infants. Micronutrient malnutrition is primarily the result of inadequate dietary intake. Dietary surveys in developing countries have consistently shown that multiple micronutrient deficiencies, rather than single deficiencies, are common, and that low dietary intakes and poor bioavailability of micronutrients account for the high prevalence of these multiple deficiencies. Recent evidence concerning increased micronutrient supplementation suggests the following: (1) Enhancing vitamin A intake reduces maternal mortality. (2) Increasing calcium and magnesium intake can reduce the risk of death from eclampsia. (3) Ensuring adequate intake of iron, zinc, iodine, calcium, magnesium, and folic acid during pregnancy can improve pregnancy outcome. (4) Increasing the intake of folic acid before pregnancy can reduce birth defects. (5) Providing zinc, calcium, and magnesium supplements during pregnancy can improve birth weight and reduce prematurity, especially among high-risk women. (6) Improving the maternal intake of many nutrients directly enhances the quality of breastmilk. In addition, micronutrients play an essential role in the function of the immune system, and deficiencies in them influence the rate, duration, and severity of infections. Infection rates during pregnancy or lactation, including reproductive tract infections, increase because of deficiencies in iron, vitamin A, and zinc. Also, low serum vitamin A levels in pregnant women have been associated with increased transmission of HIV to infants, increased transition from HIV to AIDS among infants, and increased infant mortality from AIDS. Solutions to prevent or eliminate micronutrient malnutrition include nutrient supplementation of women of childbearing age before and after pregnancy through repeated reproductive cycles. Combined supplements are usually more effective in improving micronutrient status than are single supplements, since women are usually deficient in more than one micronutrient. In addition, universal or targeted food fortification, which has proved cost- effective, can be an important strategy in preventing micronutrient malnutrition. Includes references. (Author abstract, modified)