Effect of first-line antituberculous treatment on vitamin D level in patients with pulmonary tuberculosis

Objective To explore the effect of first-line anti-tuberculosis treatment on vitamin D level in patients with pulmonary tuberculosis, and to master the changes of vitamin D level in the course of treatment, so as to provide a scientific basis for tuberculosis and nutrition health education in Shenzhen. Methods A total of 100 patients diagnosed as smear-positive pulmonary tuberculosis and receiving initial treatment in 2016 were enrolled and all the patients were treated with the standardized short-course chemotherapy regimens. The blood samples were extracted before treatment and at the ends of intensive and continuation phase. The 25-hydroxyvitamin D[25-(OH)D] concentrations were determined by chemiluminescence (CLIA)at each time point. The change of 25-(OH)D concentrations during anti-tuberculosis treatment was analyzed and the differences of vitamin D levels between different time points were identified. Results 79(79.0%), 94(94.0%) and 96(96.0%)patients were found vitamin D deficiency before treatment and at the end of the intensive and continuation phases respectively, which showed an upward trend(χ2=15.543, P<0.001)and the 25-(OH)D concentrations were (15.74±6.54)ng/ml, (12.56±5.15)ng/ml, (11.51±4.28)ng/ml, respectively. During the whole course of treatment, the 25-(OH)D concentration decreased by 26.9% or (4.23±6.75)ng/ml(t=6.257, P<0.001), wherein it decreased (3.18±5.24)ng/ml in intensive phase (t=6.069, P<0.001) and (1.05±4.86)ng/ml in continuation phase (t=2.154, P=0.034). The former had a greater decreased value (t=2.836, P=0.006). There were 77 (77.0%) and 55 (55.0%) patients with 25-(OH)D concentration reduction in intensive and continuation phases respectively(χ2=9.680, P=0.003), of which 41 patients (41.0%) continued to decline. Conclusion Once anti-tuberculosis treatment is conducted, the vitamin D level will decrease rapidly in the intensive phase and continue decreasing throughout the course of treatment, which leads to a general lack of vitamin D in patients with primary pulmonary tuberculosis. First-line anti-tuberculosis drugs may be the main cause for vitamin D level reduction. Therefore, it is necessary for clinicians to strengthen vitamin D health education for each patient throughout the treatment period, especially for those at high risk of vitamin D deficiency who should be recommended adjuvant vitamin D supplementation therapy. Key words: Pulmonary tuberculosis; Vitamin D deficiency; 25-hydroxyvitamin D; Anti-tuberculosis drug