title: Vitamin D toxicity resulting from overzealous correction of vitamin D deficiency.
abstract: BACKGROUND
  Vitamin D toxicity, often considered rare, can be life-threatening and associated with substantial morbidity, if not identified promptly.
  
  
  OBJECTIVE
  To describe clinical and biochemical features, risk factors and management of patients with vitamin D toxicity seen between January 2011 and January 2013.
  
  
  METHODS
  Patients presenting with vitamin D toxicity, between January 2011 and January 2013, at single tertiary care centre in Delhi-NCR, India, were included. Evaluation included detailed clinical history and biochemical tests including serum calcium, phosphorus, creatinine, intact parathyroid hormone and 25-hydroxyvitamin D (25(OH)D).
  
  
  RESULTS
  Sixteen patients with vitamin D toxicity could be identified. Clinical manifestations included nausea, vomiting, altered sensorium, constipation, pancreatitis, acute kidney injury and weight loss. Median (range) age was 64·5 (42-86) years. Median (range) serum 25(OH)D level and median (range) serum total serum calcium level were 371 (175-1161) ng/ml and 13·0 (11·1-15·7) mg/dl, respectively. Overdose of vitamin D caused by prescription of mega-doses of vitamin D was the cause of vitamin D toxicity in all cases. Median (range) cumulative vitamin D dose was 3,600,000 (2,220,000-6,360,000) IU.
  
  
  CONCLUSIONS
  Our data demonstrate an emergence of vitamin D toxicity as an increasingly common cause of symptomatic hypercalcaemia. Irrational use of vitamin D in mega-doses resulted in vitamin D toxicity in all cases. Awareness among healthcare providers regarding the toxic potential of high doses of vitamin D and cautious use of vitamin D supplements is the key to prevent this condition.
authors.affiliation: Division of Endocrinology and Diabetes, Medanta, the Medicity, Gurgaon, India.
authors.forename: Parjeet
authors.initials: P
authors.lastname: Kaur
authors.affiliation: Division of Endocrinology and Diabetes, Medanta, the Medicity, Gurgaon, India.
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Mishra
authors.affiliation: Division of Endocrinology and Diabetes, Medanta, the Medicity, Gurgaon, India.
authors.forename: Ambrish
authors.initials: A
authors.lastname: Mithal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D019587:Dietary Supplements / Q000009:adverse effects*; D062787:Drug Overdose / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007194:India; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D062606:Tertiary Care Centers / Q000706:statistics & numerical data; D014807:Vitamin D / Q000009:adverse effects* / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000188:drug therapy*; D014815:Vitamins / Q000009:adverse effects
chemical_list: D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; D010758:Phosphorus; C104450:25-hydroxyvitamin D; D003404:Creatinine; D002118:Calcium