Etiology of hypocalcemia developing in infants monitored in the neonatal intensive care unit

Objective: The aim of this study was to investigate the underlying causes of hypocalcemia in neonates admitted to the Neonatal Intensive Care Unit (NICU) and to propose strategies for its prevention. Methods: Serum levels of calcium, magnesium, phosphorus, alkaline phosphatase (ALP), and vitamin D were measured in both mothers and their infants. Maternal characteristics (age, gravida, parity, vitamin D supplementation, and diabetes status) were also evaluated. Results: The mean calcium level of the mothers was 8.17±0.58 mg/dL, while in infants it was significantly lower (6.99±0.71 mg/dL, p<0.001). Infant phosphorus levels (6.37±1.40 mg/dL) were significantly higher and magnesium levels (1.60±0.43 mg/dL) were lower compared to mothers (p<0.001). The mean maternal vitamin D level was 15.46±7.07 ng/mL, with only 24.6% of mothers receiving supplementation during pregnancy. Hypocalcemia was significantly more common in infants of diabetic mothers. Conclusion: Neonatal hypocalcemia is a multifactorial condition strongly associated with maternal vitamin D deficiency, low magnesium, and high phosphorus levels. Early biochemical monitoring and adequate mineral supplementation, particularly in preterm infants and those born to diabetic mothers, are crucial to prevent complications.