Vitamin D deficiency levels lead to 5-fold increase of risk of progression of tuberculosis in previously healthy patients with intra-family (household) contact with TB patients. The results of this 4-year cohort study, conducted in Pakistan, published in the May issue of the journal Emerging Infectious Diseases.
Employees of the University of the Aga Khan (Aga Khan University, Karachi, Pakistan) said it has long been established that a deficiency of vitamin D is a risk factor for activation of tuberculosis. However, the progression of the disease in previously healthy patients who had contact with tuberculosis patients has not yet been studied.

Cohort of patients in this study was those with tight "home" contact with patients recently diagnosed pulmonary tuberculosis bacteria.

The researchers collected blood samples at the initial visit, then at 6, 12 and 24 months of follow-up period. Determination of vitamin D levels in blood serum was carried out at Stanford University (California, USA).
The researchers classified the serum levels of vitamin D as low, medium or high. The average level of 25 hydro feral study participants was 9,1 ng / ml. The average level of 25 hydro feral have contacts with the absence of disease was 9.6 ng / ml, patients with TB 7.9 ng / ml in patients who received at the time of inclusion in the study of TB treatment and 5.1 ng / ml - with contact persons who received TB treatment previously.

Vitamin D levels in individuals without the disease were significantly higher than in patients with a history of tuberculosis at the time of inclusion in the study (p = 0,02).When the stratification of the cohort by level of vitamin D in 79% of the patients was found deficient in vitamin D (<20 ng / ml), 14% has been a lack of vitamin (20-30 ng / ml), and only 7% of patients noted a lack of vitamin D (> 30 ng / ml).

Average vitamin D levels were significantly lower in 74 women compared with 54 male patients (p = 0.0004).
The researchers analyzed the risk of progression to active TB, depending on the level of vitamin D. In 8% of patients (8 men) over the 4-year follow-up disease has progressed to the active form, and 7 patients with the lowest levels of serum vitamin D (<7 ng / mg), only 1 patient with an average level (7-13 ng / ml) and no patient with high levels of vitamin D is not observed the transition of the disease in active form (> 13 ng / ml) (the differences were statistically significant, p = 0,002).

At the same time, the authors note that the appointment of vitamin D during TB treatment is debated because of controversial results of clinical studies available to date on the use of vitamin D in pulmonary tuberculosis.