Case report of an infant with severe vitamin D deficiency rickets manifested as hypocalcemic seizures

Abstract

Introduction Hypocalcemic seizures are uncommon in the post-neonatal period. We report an infant with hypocalcemic seizures caused by severe deficiency of vitamin D.

Case Outline A five-month-old male infant was admitted to hospital in March 2013 with recurrent generalized afebrile seizures resistant to clonazepam therapy. At the clinical examination, the infant showed characteristic rachitic signs, so that after a blood sample was taken for laboratory testing, the infant was given infusion of 2 ml/kg of 10% of calcium gluconate at a rate of 0.5 ml/min. The treatment resulted in immediate termination of seizures and normalization of the consciousness of the infant. Blood sample analysis showed extremely low levels of free and total calcium (0.36/1.24 mmol/l) and 25(OH)D (<3 ng/ml), elevated alkaline phosphatase (878 U/l) and parathyroid hormone (283 pg/ml), and low calcium/creatinine ratio (mg/mg) in a portion of urine (0.03), while the levels of serum phosphorus, pH, total protein, albumin and creatinine were within the reference range. Wrist X-ray showed typical signs of rickets. In order to fully stabilize calcium homeostasis, along with 2,000 IU of vitamin D3 daily and standard cow’s milk formula, calcium gluconate (80 mg/kg daily) was given orally over a period of two weeks. The treatment resulted in complete stabilization of the infant’s condition and rapid improvement in laboratory, radiological and clinical findings of rickets.

Conclusion Generalized convulsions in the afebrile infant represent a serious and etiopathogenically very heterogeneous problem. Extremely rare, as in the case of our patient, it may be due to severe hypocalcemia caused by a deficiency of vitamin D.

Keywords: vitamin D deficiency; hypocalcemia; convulsions