Abstract
Vitamin A is an essential micronutrient for normal immune function. Vitamin A deficiency is common among human immunodeficiency virus (HIV)‐infected pregnant women and is associated with higher mother‐to‐child transmission of HIV‐1 and increased infant mortality. The biological mechanisms by which vitamin A deficiency could influence mother‐to‐child transmission of HIV‐1 include impairment of immune responses in both mother and infant, abnormal placental and vaginal pathology and increased HIV viral burden in breastmilk and blood. Clinical trials are currently in progress to determine whether daily micronutrient supplementation, including vitamin A, during pregnancy can reduce mother‐to‐child transmission of HIV‐1.