Contribution of Vitamin D Deficiency to Hypocalcemic Seizures in Infants Aged 1 Month to 2 Years

Abstract

Background: Vitamin D deficiency is a major contributor to disturbed calcium homeostasis, especially during early life when calcium demand is high due to rapid growth.

Objective: To evaluate the contribution of vitamin D deficiency to hypocalcemic seizures in infants aged 1 month to 2 years.

Methods: This prospective observational study was conducted in the Department of Pediatrics, Navodaya Medical College Hospital and Research Center, Raichur. A total of 100 infants aged 1 month to 2 years presenting with seizures were enrolled. Infants with CNS infection, congenital brain malformation, and maternal drug or supplement exposure affecting bone mineral metabolism were excluded. Demographic details, feeding history, seizure characteristics, clinical presentation, and biochemical parameters were recorded.

Results: Among 100 infants presenting with seizures, 27 (27.0%) had hypocalcemia. Vitamin D deficiency was identified as the major contributor to hypocalcemic seizures. Hypomagnesemia was present in 6 (6.0%) infants. The mean serum calcium level was 8.52 ± 1.713 mg/dL, while the mean corrected calcium level was 8.48 ± 1.637 mg/dL. The mean phosphorus level was 6.11 ± 1.957 mg/dL, alkaline phosphatase was 378.34 ± 233.574 U/L, and mean vitamin D level among tested infants was 13.25 ± 9.073 ng/mL. One infant with refractory seizures/status epilepticus had severe vitamin D deficiency with a vitamin D level of 4.6 ng/mL, while the infant’s mother also had markedly low vitamin D level of 5.10 ng/mL.

Conclusion: Vitamin D deficiency was a major contributor to hypocalcemic seizures among infants aged 1 month to 2 years. The low mean vitamin D level among tested infants and the documented severe infant-maternal deficiency case highlight the importance of maternal and infant vitamin D status in maintaining calcium balance.