NFKBIA and obesity due to melanocortin 4 receptor deficiency: Vitamin D supplementation did not result in reduced numbers of macrophages and NK cells in adipose tissue, but, 1,25(OH)2D3 treatment inhibited NF-κB and MAPK signaling in SVCs by increasing the expression of Iκbα and Dusp1. As a result, 1,25(OH)2D3 reduced the production of pro-inflammatory cytokines, which are increased by obesity.