Vitamin D is present in food either naturally or by fortification and included in nutritional supplements. It is also synthesized photochemically by the skin from ultraviolet B radiation. Vitamin D synthesis varies by season and with latitude as well as according to intensity of skin pigmentation. Recent research in the United States found lower circulating levels of 25 (OH) D, the primary indicator of vitamin D status, among minority women who were either pregnant or in their reproductive years. The extent to which maternal vitamin D has an influence on the course and outcome of human pregnancy remains to be more completely studied. We propose to use the HPLC method to assay cholecaliferol (vitamin D3) and ergocalciferol (vitamin D2) to assess maternal vitamin D status. This will be accomplished by analyzing existing fasting samples and data derived from the 2001-2006 cohort (N=1141) of young, low income minority gravidae from Camden, New Jersey to determine: