Vitamin D supplementation and testing in the UK: costly but ineffective?BMJ 2021; 372 doi: https://doi.org/10.1136/bmj.n484 (Published 02 March 2021) Cite this as: BMJ 2021;372:n484
- Mark J Bolland, associate professor12,
- Alison Avenell, professor3,
- Karen Smith, consultant clinical scientist4,
- Miles D Witham, professor5,
- Andrew Grey, associate professor1
- 1Department of Medicine, University of Auckland, Auckland 1142, New Zealand
- 2Department of Endocrinology, Greenlane Clinical Centre, Auckland, New Zealand
- 3Health Services Research Unit, University of Aberdeen, Aberdeen, UK
- 4Department of Clinical Biochemistry, Glasgow Royal Infirmary, Glasgow, UK
- 5NIHR Newcastle Biomedical Research Centre, Newcastle University and Newcastle upon Tyne Hospitals Trust, Newcastle upon Tyne, UK
- Correspondence to: M J Bolland
Vitamin D supplementation is a hot topic, both in the scientific literature1 and in the media, which often portrays it as a panacea for disease.23 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.14 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.
Vitamin D prescriptions in the UK have increased about 14-fold from 2 million to 27 million a year over the past 18 years, and prescription costs have increased from ₤13m to ₤111m (fig 1). The trends differ from those for prescriptions of osteoporosis medications, suggesting the increase is not because of co-prescription of vitamin D with those drugs.
The NHS also spends large amounts on measuring vitamin D stores (as serum 25-hydroxyvitamin D).56 Large increases in requests for tests have been reported from primary care practices in England,78 and data from four laboratories in each country of the UK show at least 10-fold increases in tests performed since 2001 (fig 2). Collectively, these four laboratories serve populations of about 8.4 …