Evaluation of vitamin status in patients with pulmonary tuberculosis

Vitamins are known to be associated with immunity and nutrition. Moreover, vitamin deficiency can affect host immunity to various infectious diseases, including tuberculosis. Although patients with tuberculosis often have vitamin D deficiency, little is known about the levels of other vitamins. Here, we aimed to investigate the status of vitamins A, B₁₂, D, and E in patients with tuberculosis. We also aimed to investigate the clinical and laboratory variables related to vitamin status in patients with tuberculosis.

We performed a case-control study to investigate the serum vitamin concentrations in 152 patients with tuberculosis and 137 control subjects. The concentrations of vitamin A, vitamin D, vitamin E, homocysteine, and methylmalonic acid were measured using high-performance liquid chromatography (HPLC) or HPLC-tandem mass spectrometry. Patient demographic data and other biochemical parameters were also analyzed.

The serum concentrations of vitamins A, D, and E were significantly lower in patients with tuberculosis than in control subjects (1.4 vs. 2.0 μmol/L, P < 0.001; 10.6 vs. 19.3 ng/mL, P < 0.001; and 22.8 vs. 30.6 μmol/L, P < 0.001, respectively). In contrast, the methylmalonic acid levels were higher in patients with tuberculosis (134.9 vs. 110.8 nmol/L, P < 0.001). The prevalences of vitamin deficiencies were significantly higher in patients with tuberculosis. Moreover, multiple vitamin deficiencies were only observed in patients with tuberculosis (22.4% of all patients with tuberculosis vs. 0% of all control subjects). Positive correlations among vitamin A, D, and E concentrations were observed (vitamins A and D, r = 0.395; vitamins D and E, r = 0.342; and vitamins A and E, r = 0.427, P < 0.001). Body mass index, total cholesterol, low-density lipoprotein, iron, and total iron-binding capacity all showed positive correlations with vitamin A, D, and E concentrations.

Vitamin deficiencies are common in patients with tuberculosis. Further research investigating the clinical importance of vitamin and nutritional status in patients with tuberculosis is needed.