Vitamin D intoxication due to overdose of vitamin D2 tablets in a child

Abstract

A young girls took irregularly Vitamin D2 tablets (0.25 mg/tablet, each tablet contains 10 000 IU vitamin D2) purchased by her parents at a pharmacy since she was 1.5 years old. The girl took 1 tablet at a time, once to thrice daily, occasionally missing. Five months later, she developed polydipsia and polyuria. She drank more than 2 000 ml water every day, urinated once every 0.5-1 hour, and urinated more than 5 times every night. Her maximum daily urine volume could reach 3 400 ml, and her urine was transparent as clear water. Three weeks after the symptoms appeared, laboratory tests in another hospital showed that blood calcium was 4.34 mmol/L, blood phosphorus was 2.65 mmol/L, and 24-hours urine calcium was 8.0 mmol. Vitamin D poisoning was suspected and her parents were asked to stop feeding the girl vitamin D2 tablets. Rehydration, diuretics and other treatments were given. After 3 days, her blood calcium decreased to 3.60 mmol/L. After 6 days, she was transferred to Peking University First Hospital, where she continued to receive rehydration and symptomatic treatments with a low calcium and phosphorus diet. And after 8 days, the blood calcium was 2.47 mmol/L and 24-hours urine calcium was 2.7 mmol. Her symptoms of polydipsia and polyuria improved and she was discharged. Telephone follow-up 1 month after discharge, the girl′s polydipsia and polyuria disappeared and her urine examination was normal. Key words: Vitamin D; Drug overdose; Poisoning; Medication errors; Child