PT - JOURNAL ARTICLE AU - Ruth Dobson AU - Hannah R Cock AU - Peter Brex AU - Gavin Giovannoni TI - Vitamin D supplementation AID - 10.1136/practneurol-2017-001720 DP - 2017 Sep 23 TA - Practical Neurology PG - practneurol-2017-001720 4099 - http://pn.bmj.com/content/early/2017/09/24/practneurol-2017-001720.short 4100 - http://pn.bmj.com/content/early/2017/09/24/practneurol-2017-001720.full AB - Vitamin D testing and supplementation is of great interest to neurologists and their patients. Recommended nutritional intakes of vitamin D in the UK remain focused on bone health, despite increasing evidence for a role outside this area. Here we discuss how neurologists might approach vitamin D testing and supplementation, focusing on two conditions associated with vitamin D deficiency that have an increased risk of downstream complications resulting from these: multiple sclerosis and epilepsy. We set out a rationale for testing serum 25-hydroxyvitamin D concentrations and discuss our personal practice in terms of supplementation, with evidence where available.