INFANTILE HYPOCALCAEMIC SEIZURE AND VITAMIN D DEFICIENCY

Abstract

INTRODUCTION/BACKGROUND
Growing evidence suggests that vitamin D is essential for maternal and child health in many aspects. Nevertheless, a severe manifestation of vitamin D deficiency in the form of hypocalcaemic seizures continue to occur among Malaysian infants. Methodology A descriptive cross-sectional study was performed in the Paediatric Endocrinology Unit, Hospital Putrajaya. Records of all infants with hypercalcaemic seizures managed by our unit between January 2015 until April 2024 were retrieved from the electronic database system. Causes of hypercalcaemic seizure among this group of patients were identified. Further clinical, biochemical and hormonal results to assess the calcium-vitamin D-PTH axis were analysed.

CASE
A total of 24 patients were treated for hypercalcaemic seizures during the study period. Sixteen patients were male. Majority (75%) of the patients had hypercalcaemic seizures secondary to vitamin D deficiency, while 25% had hypoparathyroidism. Among the group of hypercalcaemic seizures secondary to vitamin D deficiency, the median age of presentation was 8 weeks. Their mean corrected calcium, phosphorus, magnesium and ALP on presentation were 1.4 mmol/L, 2.35 mmol/L, 0.73 mmol/L and 690 U/L respectively. Mean iPTH and vitamin D levels of the patients were 19 pmol/L and 16.4 nmol/L, respectively. Maternal vitamin D levels were available for 7 mothers, showing a low mean value of 28.7 nmol/L. All patients with hypoparathyroidism in this study had concomitant vitamin D deficiency or insufficiency. The median age of presentation was 3.5 weeks. Their mean corrected calcium, phosphorus, magnesium and ALP upon presentation were 1.64 mmol/L, 2.80 mmol/L, 0.64 mmol/L and 384 U/L, respectively. Mean iPTH and vitamin D levels were 2.3 pmol/L and 41.7 nmol/L, respectively.

CONCLUSION
Vitamin D deficiency or insufficiency was present in all patients in our study population. Vitamin D deficiency remains the predominant cause of hypocalcaemic seizure. Thus, vitamin D supplementation for all pregnant women should be encouraged as part of routine care. All infants during the first year of life should be encouraged to receive an oral vitamin D supplementation.