A review of the growing risk of vitamin D toxicity from inappropriate practice

Vitamin D is a particularly important sterol hormone, with evidence emerging of its beneficial effects well beyond bone. In consequence of this and increased global recognition of vitamin D deficiency in the general population, there has been a resurgence in treatment with vitamin D preparations. However, the increasing use of vitamin D treatments has also seen a substantial increase in the number of reports of vitamin D intoxication, with the majority (75%) of reports published since 2010. Many of these cases are a consequence of inappropriate prescribing, and the use of high‐dose over‐the‐counter preparations or unlicensed preparations. This review highlights that the majority of cases were preventable and discusses the inappropriate use of poorly formulated, and unlicensed vitamin D preparations.