This report is based on observations during the conduct of a study of hypocalcemia in infants and children. In a study of 50 cases, 13 exclusively breast fed infants manifesting with hypocalcemic seizures were confirmed to have vitamin D deficiency. None of the 13 infants had received vitamin D supplementation. All of them had biochemical evidence of hyperparathyroidism and low levels of 25 (OH) Vit D3 and promptly responded to therapy with vitamin D and calcium. All the mothers of these 13 infants had low levels of 25 (OH) Vit D3. Mothers of 5 infants had reported reduced exposure to sunlight due to religious reasons. This report emphasizes the need to supplement Vitamin D in exclusively breast fed infants and also to encourage exposure to sunlight in them and their mothers.