TNF and congestive heart failure: Low 25(OH) D concentrations are associated with elevated tumor necrosis factor-alpha (TNF-α) concentrations (17), and randomized controlled studies among critically ill patients and those with congestive heart failure report that vitamin D supplementation leads to significant reductions in interleukin 6 (IL-6) and C-reactive protein (CRP) concentrations (18), and resulted in lower tumor necrosis factor-alpha (TNF-α) and increased anti-inflammatory IL-10 concentrations (19).