Discussion
TB, PTB, tuberculosis, deaths, renal calculi
ADVERSE EVENTS, ADVERSE EVENT, LATENT TB, TUBERCULOSIS, INFECTION, ADVERSE EVENT
At the initiation of our study, we observed most of our patients suffering from active PTB being deficient in vitamin D with mean value at 14.2 ± 8.7ng/ml (Normal:25–80 ng/ml). This is in agreement with similar studies across the globe; a study in US adults acknowledged the inverse relationship of vitamin D levels with the risk of latent TB infection (LTBI) and another in Sudan connected low vitamin D Levels with increased risk of PTB [With regards to the therapeutic value of vitamin D in the treatment of TB, increase in vitamin D levels in serum as a result of supplementation did not translate to significant improvement in time to sputum smear and culture conversion in comparison with the placebo group. This is in agreement with similar studies investigating the relationship between vitamin D and PTB [No significant difference was detected in the safety profile (non-serious and serious adverse events) and mortality profile (all-cause deaths) between the two groups. The most reported non-serious adverse event in 14 patients out 846 was renal calculi. Adverse events and deaths were evenly distributed between the two groups.Our study has several strengths, including a large sample size (n = 846) with an appropriate period of follow up (2 years). Participants also received a substantial dose of vitamin D to avoid the possibility of false negative results as criticized by some in the earlier mentioned studies. The participants were closely followed up regularly throughout the study period and the administration of the intervention was directly observed, ensuring good compliance to medications and thus eliminating the confounding effect of non-compliance contributing to relapse. The proportion of missing outcome data was small and comparable in both the groups. Therefore, our findings have a high degree of validity.The main limitation of our study was that sputum cultures for tuberculosis was not done after 6 months of routine follow up in all patients, which can have led us to miss a few cases of relapse. Sputum samples were examined for Acid Fast Bacilli, which has a relatively lower sensitivity compared to investigations such as GeneXpert, which could have further added up to the limitations [