Vitamin A is essential for reproduction (Semba, 2002). Male animals that are deficient in vitamin A are not as able to produce sperm. Low vitamin-A levels are also hypothesized to negatively affect female fertility. Vitamin-A deficiency has also been associated with placental infections. Pregnancy increases the risk of vitamin-A deficiency for both the mother and newborn, and vitamin-A deficiency in the HIV-positive, pregnant mother has been associated with increased infant mortality