Background: Calcium deficiency is common in pregnant women and newborn infants. There are few data about the prevalence of calcium deficiency during pregnancy and infancy in Algeria. We assessed calcium status of pregnant women and their neonates in Sidi Bel Abbes, west of Algeria. The current study aimed to determine the prevalence of hypocalcemia in pregnancy and in their new born and to correlate maternal calcium status with neonates' calcium and birth weight.