Vitamin D is a hormone present in the human body to manage levels of some essential electrolytes such as calcium and phosphate. Vitamin D is important for bone formation and prevention of bone breakdown (osteoporosis) as the investigators age. There is also new evidence that links vitamin D to function of our immune system as well. Even though our bodies can make vitamin D and can also obtain vitamin D from our diet, most adults, especially patients with tuberculosis have low vitamin D levels (are vitamin D deficient) that need to be corrected. Full correction of low vitamin D levels requires 6 weeks or more of weekly vitamin D supplements. There are several benefits to correcting vitamin D deficiency (better bone health, better balance of calcium and phosphate), but it is not known whether correcting vitamin D deficiency will lead to a better immune response to tuberculosis. Preliminary data does suggest that vitamin D increases the levels of an antimicrobial molecule (cathelicidin LL-37) in the body, possibly leading to better immunity against tuberculosis. The primary objective of this pilot study is to assess the relationship of vitamin D levels in patients with active pulmonary tuberculosis to levels of LL-37 cathelicidin in sputum and whole blood. The results of this study are needed in preparation for larger studies that will evaluate the role of vitamin D supplementation as adjunctive therapy to standard medical treatment for tuberculosis.