In recent years, vitamin D has captured the attention of the scientific and medical communities, government and regulatory bodies, the media and the general public. This has led to an expansion in the scientific literature, re-evaluation of dietary recommendations and an increase in requests for vitamin D tests. In July 2016, the UK Scientific Advisory Committee on Nutrition (SACN) published revised vitamin D dietary requirements for the UK population, which included – for the first time – a recommendation of 10µg/day (400iu/day) being set for those aged 4 years and older based on musculoskeletal health outcomes.¹ Population sub-groups ‘at risk’ of vitamin D deficiency have typically included pregnant and …