Tuberculosis, or TB, is a serious infection that mainly affects the lungs. Some researchers thought vitamin D might help protect people from TB because it plays a role in the immune system. To test this idea, scientists combined data from many double-blind, placebo-controlled trials, where some people took vitamin D and others took a dummy pill.
The combined analysis included 14,619 participants. For TB infection, measured by skin or blood tests, vitamin D made no meaningful difference: about 9,557 people were studied, and the chance was roughly the same as with placebo. For active TB disease, there was also no clear benefit across 14,533 people. The results stayed the same even for people with very low vitamin D levels at the start.
Serious side effects were not increased by taking vitamin D. The researchers noted one caveat: the range of possible effects for TB disease still leaves room for a meaningful benefit, so a smaller protective effect cannot be ruled out.
Overall, this large review found no evidence that vitamin D supplements prevent TB infection or disease in the groups studied. People should not rely on vitamin D alone to protect against TB.
Common questions
Does vitamin D help prevent tuberculosis?
In this large pooled analysis of 14,619 people, vitamin D supplements did not reduce the risk of new TB infection or TB disease. The results were similar even in people with very low vitamin D levels. The researchers noted that some benefit for TB disease cannot be fully ruled out, but overall there was no clear protection.
How many people were in this vitamin D and TB analysis?
The analysis included 14,619 participants from double-blind, placebo-controlled randomized trials. The TB infection result was based on 9,557 participants, and the TB disease result was based on 14,533 participants. This is a large body of evidence, which makes the overall finding more reliable than a single small study.
Were there side effects from vitamin D in these trials?
The analysis reported that serious adverse events were not affected by vitamin D. Other safety details, such as minor side effects or dropouts, were not reported in the summary. If you take vitamin D for any reason, talk with your doctor about the right dose and whether it is appropriate for you.
Should I stop taking vitamin D to prevent TB?
This analysis looked at whether vitamin D prevents TB in trial populations, not at individual decisions. It found no clear reduction in TB infection or disease. Whether to take vitamin D depends on your own health and reasons for taking it, so discuss any changes with your doctor rather than stopping or starting on your own.
