Micronutrients and vertical transmission of HIV-1

Vertical transmission of HIV from mother to infant can occur during pregnancy, at the time of delivery, or post-natally through breast-feeding and is a major factor in the continu-ing spread of HIV infection. Inadequate nutritional status may increase the risk of vertical HIV transmission by influencing mater-nal and child factors for transmission. The potential effects on these factors include impaired systemic immune function in preg-nant women, fetuses, and children; an increased rate of clinical, immunologic, and virologic disease progression; impaired epithe-lial integrity of the placenta and genital tract; increased viral shed-ding in breast milk from inflammation of breast tissue; increased risk of low birth weight and preterm birth; and impaired gastroin-testinal immune function and integrity in fetuses and children. Micronutrient deficiencies are prevalent in many HIV-infected pop-ulations, and numerous studies have reported that these deficien-cies impair immune responses, weaken epithelial integrity, and are associated with accelerated HIV disease progression. Although low serum vitamin A concentrations were shown to be associated with an increased risk of vertical HIV transmission in prospective cohort studies, randomized, placebo-controlled trials have reported that vitamin A and other vitamin supplements do not appear to have an effect on HIV transmission during pregnancy or the intrapartum period. However, the ability of prenatal and postpartum micronu-trient supplements to reduce transmission during the breast-feeding period is still unknown.