Case report of acute vitamin D intoxication in an infant.

Introduction: Vitamin D intoxication represents a rare and potentially serious pathological condition caused by the excess of calcium and phosphorus. We are presenting an infant with vitamin D intoxication due to excessive daily administration, as well as therapeutic procedures that prevented its adverse effects.

Case Outline: A 1.5-month-old female infant, born at term, exclusively breastfed and without any complaints and abnormalities of physical findings, was observed due to the data that during the preceding month, by her mother's mistake, she had received about 200,000 IU of vitamin D3. Laboratory analyses showed a high serum level of 25(OH)D (>400 nmol/L) and calcium (2.72 mmol/L), lowered PTH (6.6 pg/ml) and high urinary calcium/creatinine ratio (1.6), while other findings, including urotract ultrasonography image, were within normal limits. Treatment based on the discontinuation of vitamin D administration, infant's forced water intake, as well as the application of 2-month prednisolone and 4-month phenobarbitone and furosemide, resulted in complete normalization of the laboratory indicators of vitamin D overdose, as well as the prevention of its adverse effects.

Conclusion: By timely recognition and adequate treatment, including triple therapy with prednisolone, phenobarbitone and furosemide, adverse effects of acute vitamin D intoxication can be prevented.