Drugs that treat can cause a deficiency of vitamin b6.

Tuberculosis

Explanation:

Tuberculosis is a bacterial infection that usually affects the lungs. Most people who become infected with this bacterium will never develop symptoms of the disease, as their immune system can control this microbe.  

Active tuberculosis occurs when infection is not contained by the immune system and typical symptoms are cough, chest pain, fever, night sweats, weight loss, and sometimes coughing up blood. Treatment is with a combination of antibiotics that should be taken for at least six months. The downside of the treatment is that the medicine used can cause vitamin B6 deficiency, which can cause other health problems.

It is therefore common for doctors to prescribe pyridoxine (vitamin B6) supplementation for patients on tuberculosis treatment. Vitamin B6 supplementation can alleviate problems caused by vitamin B6 deficiency without interfering with the treatment effect against tuberculosis.