Life-threatening complications of vitamin D intoxication due to over-the-counter supplements.
BACKGROUND
Ninety percent of hypercalcemic cases are caused by primary hyperparathyroidism or malignancy. Less frequent causes are granulomatous diseases, drug-induced diseases, and intoxications.


METHODS
We present two women with life-threatening hypercalcemia due to the intake of vitamin D-concentrated supplements, which turned out to be 100-1,000 times higher than stated on the label of over-the-counter dietary supplements. Laboratory analysis revealed ionized calcium levels of 4.00 (16.00) and 4.56 mmol/L (18.24 mg/dL) with vitamin D(25) concentrations of 1,372 and 644 nmol/L, respectively. Apart from a patient with general symptoms of hypercalcemia, a case of refractory status epilepticus after correction of serum calcium levels, and in need of prolonged ICU treatment, is described.


CONCLUSIONS
Initial drug-taking history in the presented cases did not reveal the use of over-the-counter supplements, which underlines the importance of a thorough evaluation of (non-)prescribed medication. Moreover, these supplements may contain higher levels of vitamin D than the label states. As a result, hypercalcemia may be an underlying cause for life-threatening complications, including a well-documented refractory status epilepticus.
Kaptein
Sara
S
Department of Intensive Care Medicine, Medical Center Leeuwarden, Leeuwarden, The Netherlands. sarakaptein@hotmail.com
Risselada
Arne J
AJ
Boerma
E Christiaan
EC
Egbers
Peter H M
PH
Nieboer
Peter
P
D000368:Aged; D002118:Calcium / Q000097:blood / Q000378:metabolism; D019587:Dietary Supplements / Q000506:poisoning; D064420:Drug-Related Side Effects and Adverse Reactions / Q000150:complications / Q000209:etiology; D005260:Female; D006801:Humans; D006934:Hypercalcemia / Q000150:complications / Q000209:etiology*; D049950:Hyperparathyroidism, Primary / Q000150:complications* / Q000209:etiology; D009426:Netherlands; D014807:Vitamin D / Q000097:blood* / Q000506:poisoning*
D014807:Vitamin D; D002118:Calcium