Effectiveness and strategies of iron supplementation during pregnancy.

Iron deficiency continues to be one of the most prevalent single-nutrient deficiencies in the world. Interventions are often designed to prevent the decrease in hemoglobin concentration and the decline in iron stores associated with pregnancy. Although this is believed to be desirable for both the health of the mother and the well-being of the growing fetus, some scientists disagree. Enrichment and fortification of food items, and dietary changes resulting from education interventions, have met with some success in developed countries, but not often in the developing world. A therapeutic approach to iron supplementation, rather than a public health-based approach, is used throughout much of the world but suffers from real, or perceived, problems of compliance. Large doses of iron are most often prescribed and are associated with side effects and with increased oxidative damage. Alternatively, delayed-release preparations and intermittent oral iron supplementation lead to better overall compliance and alleviate side effects. Daily iron intervention provides more protection against a decline in the storage iron pool in pregnant women than does an intermittent schedule, but the latter is generally associated with fewer side effects, better compliance, and possibly a reduction in risk of oxidative damage. An improved cost-benefit ratio associated with a lower-dose oral iron supplement may prove to be quite positive in the future. Currently, no single approach may be universally acceptable, although a moderate iron dosage protocol will likely provide the most benefit to those who require supplemental iron.