Proinflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor–alpha (TNF-α) are increased in patients with T2DM, and vitamin D addition has been shown to reduce the production of these proinflammatory cytokines in the retina by enhancing its anti-inflammatory properties (14). Here, IL6 is linked to type 2 diabetes mellitus.