Journal of Medical Biochemistry (Jan 2014)
The health benefits of vitamin D relevant for tuberculosis
Abstract
Vitamin D has an important role in numerous physiological functions. Vitamin D receptors are characterized by polymorphisms and presence in different tissues including a number of cells of the immune system. The role of vitamin D as a biological inhibitor of inflammatory hyperactivity is of particular importance. Hypovitaminosis D has been associated with many serious chronic diseases, such as autoimmune, infectious and cardiovascular diseases as well as some types of cancer. Vitamin D has an influence on the immune response to tuberculosis. Calcitriol (1,25-dihydroxycholecalciferol), the major active form of vitamin D, has shown in vitro activity against Mycobacterium tuberculosis. It has been found that susceptibility to chronic mycobacterial infections is strongly correlated with a low vitamin D intake and particular VDR alleles. Vitamin D deficiency might predispose the individuals infected with Mycobacterium tuberculosis to develop tuberculosis. Calcitriol binds to vitamin D receptors and modulates immune responses by regulating the transcription of genes responsive to vitamin D. Faster conversion of sputum mycobacterial culture in patients with pulmonary tuberculosis is associated with being a carrier of the t allele of the TaqI vitamin D receptor polymorphism. On the contrary, slower sputum culture conversion in pulmonary tuberculosis has been found in the carriers of the f allele of the FokI vitamin D receptor polymorphism. The results of in vitro studies, clinical research and population studies indicated that vitamin D deficiency might be a strong risk factor for developing TB. Vitamin D is an inexpensive, easily accessible vitamin, relevant for the prevention of tuberculosis. In addition, vitamin D could contribute to the success of tuberculosis treatment.