All cells of the adaptive immune system (dendritic cells, monocytes, T-cells and B-cells, NK cells) have VitD receptors and are responsive to the active VitD hormone (1,25(OH)D3).

The active hormonal form of Vitamin D [1,25(OH)D3] causes:

  • Potent inhibition of dendritic cell maturation (that is, decreases immune response)
  • Blocks production of pro-inflammatory cytokines such as interleukins (IL-12 and IL-13) implicated in Crohn's Disease and Ulcerative Colitis, and other autoimmune conditions, and tumor necrosis factor (TNF).


Without adequate VitD, the immune system does not function properly. Without VitD, the immune system 'misreads' immune signals and attacks healthy tissue causing inflammation.

Inflammation causes the symptoms of autoimmune disease.