Evidence from different directions, including observational and experimental studies, points to a role of vitamin D status in low-intensity chronic inflammation and insulin resistance in type 2 diabetes mellitus (T2DM). It has been recognised that insulin resistance and low-intensity chronic inflammation are risk factors for T2DM. Thus, vitamin D status can be implicated in the aetiology of TD2M. It is suggested that the relationship between vitamin D and low-intensity chronic inflammation and insulin resistance in T2DM can be mediated in part by the immune-modulating properties of the active form of vitamin D (1-α,25-dihydroxyvitamin D₃; 1,25(OH)₂D₃), which is able to down regulate the production of pro-inflammatory cytokines – particularly TNF-α, and IL-6. However, an association between vitamin D status and these features, which is independent of BMI, has been also reported. Non-calcaemic effects of vitamin D can be associated with health outcomes other than those traditionally attributed to the vitamin.