There is an evidence of abnormal metabolism in the vitamin D endocrine system of patients with leprosy. Bone deformities usually occur in patients with leprosy. Genetic factors, such as the vitamin D receptor, the major histocompatibility complex region, chromosome 20, human toll-like receptors, the natural resistance-associated macrophage protein 1, the nucleotide-binding oligomerization domain containing 2, phosphate-regulating gene with homologies to endopeptidase on the X chromosome and the tyrosine kinase growth factor receptor-ErbB-2, contribute to both vitamin D status and leprosy. The role of vitamin D in leprosy has been demonstrated by its effects on Bacillus Calmette-Guérin vaccination, vascular endothelial growth factor, prostaglandins, reactive oxygen species, reactive nitrogen intermediates, matrix metalloproteinases, antiphospholipid syndrome and the nerve growth factor. Vitamin D plays a definite role in leprosy. Vitamin D, itself, may effect on leprosy through the vitamin D receptors or may influence leprosy through indirect effects.