The vitamin D deficiency is associated with several autoimmune and chronic inflammatory diseasessuch as tuberculosis (TB) and sarcoidosis (Sr). We studied blood samples taken in March - April in Saint Petersburg area (59° north latitude) from patients with different forms of pulmonary tuberculosis, sarcoidosis, and from healthy donors, distinguishing between tuberculosis patients with short either long duration of disease. We measured the levels of calcifediol and calcitriol, prolactin in sera, cathelicidin in plasma, and the individual autoimmune profile of patients. The level of 25(OH) D was low even in healthy adult donors - 19.3±1.4 ng/ml; however in all patients it was significantly lower. Active metabolite 1.25(OH)2 D3 concentration in serum was increased only in the sarcoidosis patients. During infection the activated macrophages convert the main circulating form 25(OH) D into the active 1.25 (OH)2 D3 which induces the antibacterial peptide cathelicidin. We saw no expected increase of cathelicidin leve