Assessment of the Status of Vitamin D Among Egyptian Pregnant Women

Abstract

Maternal vitamin D deficiency is a common public health problem. Compared to non pregnant women, vitamin D metabolism is markedly altered in pregnancy. This may be due to reduced placental 1α-hydroxylase activity resulting in lower circulating calcitriol concentrations. Vitamin D, a precursor present in two forms ergocalciferol (vitamin D2) which is present in plants and some fish and cholecalciferol (vitamin D3), is synthesized in epithelial cells of skin by sunlight. Vitamin D3 is synthesized from 7-dehydrocholesterol in the skin. The vitamin D binding protein transports the vitamin D3 to the liver where it undergoes hydroxylation to 25(OH)D which is the inactive form and then to kidneys where it is hydroxylated by the enzyme 1 alpha-hydroxylase to 1,25(OH)D and this is the active form.