TNF and metabolic dysfunction-associated steatotic liver disease: However, some larger, randomized, placebo-controlled trials are required to detect the effects of vitamin D supplementation for the treatment of NAFLD and to determine the optimal levels of vitamin D. Furthermore, we found that the expression of TLR4, NF-κB, and TNF-α was downregulated by 1,25(OH)2D3 in a dose-dependent manner.