9 bacteria fought by vaccines, 5 might be fought by Vitamin D


Table

Claude AI April 2026

Vaccine Pathogen Disease Vitamin D Evidence
Hib H. influenzae type b Meningitis, pneumonia 🟡 Might fight
Pneumococcal S. pneumoniae Pneumonia, meningitis 🟡 Might fight
Meningococcal N. meningitidis Bacterial meningitis ⬜ Not known
DTaP — "P" B. pertussis Whooping cough 🟡 Might fight
DTaP — "D" C. diphtheriae Diphtheria 🟡 Might fight
DTaP — "T" C. tetani Tetanus ⬜ Not known
BCG M. tuberculosis Tuberculosis 🟢 Known to fight
Typhoid S. typhi Typhoid fever ⬜ Not known
Cholera V. cholerae Cholera ⬜ Not known

Here's the reasoning behind each rating:

🟢 TB — strongest case by far. 1,25D stimulates autophagy, which has emerged as a mechanism critical for control of intracellular pathogens such as M. tuberculosis. Perhaps the best-known immunomodulatory pathway was described by Liu and colleagues, identifying a mechanism by which vitamin D mediates the host response to tuberculosis: activation of the toll-like receptor 2 by M. tuberculosis upregulates both CYP27B1 and the vitamin D receptor in macrophages. TB is actually the pathogen where vitamin D research began — sanatoriums used sunlight exposure as a TB treatment before antibiotics existed.

🟡 Pneumococcal. Low serum concentrations of vitamin D metabolites have been identified in patients with pneumonia, and data from intervention trials with vitamin D as an investigational drug provided mixed results, with several studies providing positive outcomes in patients with pneumonia.

🟡 Hib. As discussed earlier — indirect evidence through general respiratory bacterial defense mechanisms, cathelicidin upregulation, and the shared risk factors with vitamin D deficiency in AI/AN populations.

🟡 Pertussis & Diphtheria. Vitamin D-induced expression of the antimicrobial peptide CAMP/LL37, originally characterized for its antibacterial properties, is a key component of innate immune responses that would apply broadly to respiratory bacterial pathogens including these two.

⬜ Tetanus, Meningococcal, Typhoid, Cholera. Little or no specific research linking vitamin D to these pathogens. Tetanus is a toxin-mediated disease (the bacterium itself isn't the primary threat — its toxin is), which is a mechanistically different problem where vitamin D's immune-modulating role is less relevant.

One important caveat worth noting for VitaminDWiki: despite some positive early results from smaller RCTs and early meta-analyses, population-based Phase 3 RCTs and more recent meta-analyses have tended to yield null results, and vitamin D is still not recommended for prevention or treatment of any infectious disease by any national or international body. The observational evidence is compelling but the RCT evidence is messier — partly, as you know well, because of dosing, baseline levels, and trial design issues.


Related in VitaminDWiki

Tuberculosis