The World Health Organization recommends routine vitamin A supplementation during pregnancy or lactation in areas with endemic vitamin A deficiency (where night blindness occurs), based on the expectation that supplementation will improve maternal and newborn outcomes including mortality, morbidity and prevention of anaemia or infection.The objective of this book is to review the effects of supplementation of vitamin A, or one of its derivatives, during pregnancy, alone or in combination with other vitamins and micronutrients, on maternal and newborn clinical outcomes.