Vitamin D is vital for the development and maintenance of strong bones and teeth, proper muscle function and a healthy immune system. In the UK, many people should take daily supplements, in particular pregnant and breastfeeding women, breastfed babies and young children. This free CPD module describes the important roles that vitamin D has in the body, explains which groups supplementation is particularly important for, and provides a checklist of things to consider when talking to patients and customers about vitamin D.