Vitamin D Toxicity: A Prospective Study from a Tertiary Care Centre in Kashmir Valley.

BACKGROUND

Vitamin D toxicity (VDT), a "not uncommon" cause of hypercalcemia, can be life-threatening and cause substantial morbidity, if not treated promptly.

AIMS

To describe presentation, management, and outcome in 32 patients with VDT diagnosed over 3 years.

MATERIALS AND METHODS

Patients presenting with VDT at a tertiary care centre in Srinagar Kashmir India were included. Evaluation included detailed history and biochemical tests including serum calcium, phosphate, creatinine, intact parathyroid hormone (iPTH), 25-hydroxy Vitamin D (25-OHD), and 24-hour urinary calcium.

RESULTS

The clinical manifestations of the 32 patients (median age 65; range 3-77 years) included gastrointestinal symptoms (constipation and vomiting), polyuria/polydipsia, altered sensorium, pancreatitis, acute kidney injury, and nephrocalcinosis. The median total serum calcium level was 13.95 (range 11.10-17.20) mg/dl and median 25-OHD level was 306 (range 105-2800) ng/ml. All patients had suppressed or low normal iPTH and hypercalciuria and 78% had azotemia. All patients had received multiple intramuscular injections of vitamin D. The median cumulative dose was 4,200,000 (range, 1,800,000-30,000,000) IU. The median time to resolution of hypercalcemia was 7 months (range 4-18 months).

CONCLUSION

We conclude that VDT is an increasingly common cause of symptomatic hypercalcemia. VDT needs prolonged follow up as it takes months to abate its toxicity. Enhancing awareness among general practitioners regarding the toxicity resulting from high doses of vitamin D is the key to prevent VDT. We suggest that VDT be considered in patients, especially the elderly, presenting with polyuria, polydispsia, vomiting, azotemia, or encephalopathy.