Hypocalcemic seizures in breastfed infants with rickets secondary to severe maternal vitamin D deficiency

This study was done to evaluate if nursing mothers of infants with rickets have vitamin D deficiency, and to evaluate the relationship between maternal vitamin D levels with hypocalcemic seizures in infants with rickets. We selected a cohort of breastfed infants with rickets. Infants were included in this study if they were breastfed and presented with any of the following clinical criteria: delayed motor milestones or delayed teething, were found to have specific rachitic bony signs, or presented with hypocalcemic seizures. We checked serum calcium (Ca), phosphorus (P), alkaline phosphatase, 25 hydroxy vitamin D [25(OH)D] and parathyroid hormone (PTH) levels in both infants and their mothers. Out of 32 children who met the clinical criteria for rickets, 23 (72%) had vitamin D level less than 20 ng mL(-1). Twenty two mothers (69%) had vitamin D deficiency (25 hydroxy vitamin D < 20 ng mL(-1)). Mothers of nine infants who presented with hypocalcemic seizures had severe vitamin D deficiency, (p = 0.005). We conclude that maternal vitamin D deficiency is common in nursing mothers of infants diagnosed with rickets. Invariably mothers of infants presenting with hypocalcemic seizures have severe vitamin D deficiency. Hypocalcemic seizures in infants secondary to maternal vitamin D deficiency might be prevented by supplementation of vitamin D.