Vitamin D supplementation is a hot topic, both in the scientific literature and in the media, which often portrays it as a panacea for disease. Since 2013, vitamin D has been one of the 20 most commonly prescribed medications in the English NHS. Of the top 20 agents in 2018, vitamin D had the fourth largest increase in both prescriptions and costs since 2008. Testing for vitamin D has also increased. At the same time, the effectiveness of supplements for conditions other than the deficiency diseases rickets and osteomalacia has been questioned. It is therefore important to ask whether the investment by the NHS has been accompanied by improvements in health outcomes and if current guidelines are the best use of resources.
We thank the following for providing data on vitamin D measurements from their laboratories: Margaret McDonnell, Belfast Health and Social Care Trust; Carol Evans, University Hospital Wales; Anthea Patterson, Royal Cornwall Hospitals NHS Trust; and Ian Rothnie, Aberdeen Royal Infirmary.
Contributors and sources: MB, AA, AG, and MW are clinical academics with an interest in vitamin D deficiency. The article arose out of discussions between the authors on the role of vitamin D supplements during a sabbatical by MB where he visited the research groups of AA and MW. MB performed the analyses. MB drafted the paper. All authors critically reviewed and improved it. MB is the guarantor for the article.