Vitamin A may combat tuberculosis

Vitamin A may play an important role in combating tuberculosis, a recent study found.

UCLA researchers wanted to investigate if nutrients played a role in helping the immune system fight infections, focusing on TB as it affects more than 2 billion people worldwide and causes 2 million deaths each year.

The study, published in the Journal of Immunology, describes how vitamin A helps the immune system fight TB by reducing cholesterol, which can be used by TB bacteria for nutrition and other needs.

"If we can reduce the amount of cholesterol in a cell infected with tuberculosis, we may be able to aid the immune system in better responding to the infection," senior author Philip Liu, an assistant professor of medicine in the divisions of dermatology and orthopedic surgery at UCLA's David Geffen School of Medicine and Orthopaedic Hospital Research Center, said in a statement. "Understanding how nutrients like vitamin A are utilized by our immune system to fight infections may provide new treatment approaches."

Researchers studied the effects of active vitamin A, retinoic acid, and were surprised to discover that it couldn't fight the tuberculosis bacteria without the expression of a gene called NPC2.

"The cells need vitamin A to trigger this defense process and NPC2 to carry it out," said co-first author Matthew Wheelwright, an undergraduate research assistant to Liu's study when the research was conducted. "We may be able to target these pathways that regulate cholesterol within a cell to help the immune system respond to infection."

Vitamin A's mechanism is unique given that when the team compared its effects to that of vitamin D, a nutrient they had previously studied, only vitamin A lowered cholesterol levels.

However, before the scientists can recommend vitamin A to combat TB, more research is needed, especially on the process of how vitamin A goes from its inactive form, retinol, to its active, TB-fighting form, the study's authors said.