RT Journal Article SR Electronic T1 Vitamin D supplementation JF Practical Neurology JO Pract Neurol FD BMJ Publishing Group Ltd SP practneurol-2017-001720 DO 10.1136/practneurol-2017-001720 A1 Ruth Dobson A1 Hannah R Cock A1 Peter Brex A1 Gavin Giovannoni YR 2017 UL http://pn.bmj.com/content/early/2017/09/24/practneurol-2017-001720.abstract 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.