REN and vitamin D deficiency: On top of that, scientists have found that vitamin D deficiency may increase the risk of atrial fibrillation (AF), possibly since vitamin D can reduce inflammation by inducing interleukin 10 (IL-10) production and reducing the production of interferon-γ, and tumor necrosis factor-alpha (TNF-α), IL-6, and IL-12 [51], and vitamin D inhabitant the renin-angiotensin system (RAS) [52].