D-VITAMINS AND THE IMMUNE-SYSTEM

In the animal body vitamin D is metabolised to 1,25-dihydroxyvitamin D (DVD), for which receptors exist in many cell types, also in macropha ges, activated lymphocytes and natural killer cells. DVD is active as an immunomodulator, During deficiency of vitamin D (at rickets and ost eomalacia), the functional capacity of the immune system is diminished , accompanied by increased rates and severity of infections (f. e. tub erculosis). The significance of DVD for macrophages, T- and B-lymphocy tes and natural killer cells is described. DVD stimulates the formatio n and activity of suppressor T-lymphocytes and inhibits the developmen t of autoimmune-diseases.