The study will determine, by testing of blood samples, if levels of maternal Vitamin D during pregnancy affect the transmission of Cytomegalovirus (CMV) to infants. The project will use Dr. Kovacs’ Natural History Study of HIV-infected women and their children covering a period of 25 years which includes an extensive repository of clinical specimens and a comprehensive clinical database such as information on CMV infections. If found relevant, supplementation during pregnancy would become a simple and cost-effective way to prevent problems like childhood deafness, neurologic, growth and developmental problems among children.