Vitamin D was found in a recent study to play a big role in helping the body fight tuberculosis. And researchers say their findings suggest Vitamin D can bolster the immune system in its fight against all infections.

The study, led by Dr. Mario Fabri of UCLA, found that with sufficient levels of Vitamin D, white blood cells will release proteins that tell infected immune cells to attack invading bacteria.

Vitamin D made all the difference in the study of tuberculosis. When enough of the vitamin was present, there was an 85 percent reduction of colony-forming bacteria in cells.

Tuberculosis, a highly contagious infection, usually of the lungs, is estimated to kill 1.8 million people worldwide each year.

New infections are now rare in the United States, with most new cases found in HIV patients and others with weakened immune systems. But before 1946, when the first antibiotic was developed, it was a feared and often-deadly disease that afflicted many. It was commonly called “consumption” because those afflicted were almost “consumed” by it, losing so much weight as to appear skeletal.

The most common symptoms of TB, besides weight loss, are night sweats, coupled with a chronic, productive cough, with blood appearing in the sputum.

In the U.S. in the first half of the 20th century, TB patients were usually sent to sanatoriums, where they were told to lie in the sun. Doctors knew from experience that sunlight seemed to help patients recover, but had no idea why. Vitamin D is manufactured in the body when a person is in sunlight.

The new findings explain why those with darker skin, who get less Vitamin D from the sun, are more likely to contract tuberculosis and less able to fight the infection once they’ve contracted it. TB is most common in Africa and parts of Asia.

But the researchers also found that adding Vitamin D to the diet or the use of supplements can make up for any deficiency.

“Our findings suggest that increasing vitamin D levels through supplementation may improve the immune response to infections such as tuberculosis,” said Dr. Fabri, now of the University of Cologne in Germany.