Prenatal vitamin and mineral supplements are designed to meet the specific nutritional needs of both the mother and unborn child.  During pregnancy, the body requires higher levels of key nutrients. In most prenatal multivitamins, levels of folic acid, calcium and iron are increased, while vitamin A is often found in lower levels. Folic acid is critical in the prevention of neural tube defects, and iron is required to support increased blood production during pregnancy and avoid anemia.  Vitamin A is best supplemented in the form of beta-carotene, which converts to retinol (vitamin A) in the body, as studies have linked high doses of animal-source vitamin A to increased incidence of birth defects. Because iron can block calcium absorption, it may be best to supplement calcium separately.

In addition to prenatal multivitamins, pregnant and nursing mothers should consider additional supplements.  DHA from algae or fish oil, for example, helps fetal retinal and brain development, and low levels of DHA contribute to post-partum depression.  Vitamin D supports fetal growth, including nervous system and immune system development, and probtioics support the immune system, reduce vaginal infections, and reduce risk of allergies in the infant.