Vitamin D and tuberculosis: an overestimated protection?

#Tuberculosis #VitaminD #InfectiousDiseases  


Despite effective treatments and well-established prevention strategies, tuberculosis (TB) remains one of the leading causes of infectious mortality worldwide, affecting more than 10 million people each year. The challenge is particularly acute in countries with poor living conditions, limited access to healthcare, and high rates of HIV co-infection, which increases population vulnerability. Therefore, prevention continues to be a top public health priority.  

In this context, vitamin D has attracted growing interest due to its immunomodulatory properties. It contributes to macrophage activation, regulation of inflammatory responses, and synthesis of antimicrobial peptides involved in the control of tuberculosis infection. Many studies suggest that vitamin D deficiency may be a risk factor for infection with Mycobacterium tuberculosis or progression to active disease. These findings have naturally led to considering vitamin D supplementation as a complementary preventive strategy.  

However, the results of various studies remain mixed, differing based on populations, vitamin D doses, and evaluation criteria. Due to the lack of consensus, clinical recommendations on the preventive use of vitamin D against tuberculosis remain unclear. This meta-analysis was therefore conducted to better understand the relationship between vitamin D supplementation and tuberculosis prevention.      

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Vitamin D dosing—but what are the effects?  

Six studies including 15,677 participants from high-burden TB countries were selected. Participants were TB-free at baseline—either children or adults—with 25(OH)D levels ranging from deficient to normal. Vitamin D was administered orally using various protocols—daily, weekly, or as bolus doses—over durations ranging from three to thirty-six months. Three outcome measures were assessed: TB infection (diagnosed by IGRA or TST), incidence of active tuberculosis, and occurrence of serious adverse events.  

The analysis showed no significant preventive effect of vitamin D supplementation on TB infection or progression to active TB. The safety profile was comparable between the vitamin D and placebo groups, with no increase in serious adverse events. Subgroup analyses—whether based on baseline vitamin D status or supplementation duration—did not demonstrate any additional benefit. Regardless of the dosing regimen or population, no clear preventive effect was observed.  

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Preventing TB with vitamin D: false hope or targeted approach?  

Tuberculosis continues to be one of the deadliest infectious diseases globally, despite the availability of effective treatments. One of the ongoing challenges is to identify simple and accessible preventive strategies, especially in high-endemic regions. The idea of using vitamin D, known for its immunomodulatory functions, as a preventive tool has garnered increasing attention but remains scientifically controversial.  

The objective of this study was to rigorously assess whether vitamin D supplementation could reduce the risk of TB infection or progression to active disease. The results are unequivocal: no significant preventive benefit was demonstrated—neither in reducing infection rates nor in preventing active tuberculosis. Routine supplementation does not appear to be justified in the general population.

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