Vitamin D is the precursor of 1, 25 dihydroxy vitamin D3, the steroid hormone required for calcium absorption, bone development and growth in children. 90% of vitamin D is produced in the skin from the action of sunlight and remaining 10% is obtained from dietary sources. Vitamin D deficiency is major issue in Pakistan and in pregnancy it has been associated with adverse outcomes like pre-eclampsia, gestational diabetes mellitus and preterm birth. Deficiency during infancy may lead to rickets in infants. This study was aimed to find level of vitamin D in relation with calcium in pregnancy and lactation. For the assessment of Vitamin D, blood samples of healthy, pregnant and lactating mothers were assessed with the help of ELISA. This book will highlight the status of vitamin D in pregnant and lactating women and their comparison with healthy women.