A new study suggests that a low-cost nutrient could help drugs fight tuberculosis more effectively. The study found that anti-tuberculosis drugs killed more bacteria in laboratory mice when the mice received vitamin C. The authors say the findings could offer a low-cost, safe way to reduce the long treatment time for one of the world's deadliest diseases. They also say the vitamin supplement could offer a way to fight tuberculosis that is resistant to antibiotic drugs. Tuberculosis, or TB, is one of the leading causes of death worldwide. The World Health Organization says 1.7 million people died of the disease last year. About 600,000 cases were resistant to the leading drug out of more than 10 million new infections.