# Potential Role of Vitamins A, B, C, D and E in TB Treatment and Prevention: A Narrative Review
## 4 Conclusions  
Our reading review shows a strong link between vitamins A, B, C, D and E and TB. This seems to be due both to their modulatory action in inflammation process, to the nutritional status which, where it is poor, correlates on the one hand with a hypovitaminosis and on the other with an increased risk of TB onset, and to the action of vitamins which potentially have a direct link with _M. tuberculosis._  
Supplementation with multiple micronutrients (including zinc) rather than VA alone may be more beneficial in TB. In the absence of evidence of the beneficial effect of VA supplementation alone, interventions that include both VA and zinc may be a better choice [38].  
WHO recommend Pyridoxine (vitamin B6) when high-dose Isoniaid is administered and in patients with diabetes, uremia, HIV infection, seizure disorders, alcohol abuse, malnutrition or peripheral neuropathy. Additionally, pregnant and postpartum women and exclusively breastfed infants should receive vitamin B6 while taking Isoniaid. (Normal dose of pyridoxine when used prophylatically for prevention of neuropathy in patients taking Isoniaid is 10-25 mg/day.)  
For VC, the daily dose in a normal human diet is far below the levels needed for optimal activity in vitro against MTB; megadoses of VC have been administered to human patients, leading to high VC plasma concentrations (up to 49 mM), which were shown to be safe [64]. So it will be very interesting performing randomized clinical trials in the future prospect to better understand if VC is a means to achieving faster sputum smear-negative conversion, which would indicate a quicker reduction in the mycobacterial burden, and if it might shorten TB treatment, leading to a reduction in the incidences of both drug resistance development and disease relapse.  
While for VD, considering the few side effects, even if administered in high doses, given the low cost of the drug and given the evidence of in vitro efficacy and dubious in vivo results, it would be useful to measure VD in all patients with TB, and in patients at risk of developing active TB, and administer supplementation of VD. However, further clinical trials are necessary to identify any confounding factors in vivo and to determine the possible usefulness of VD in the prophylaxis and treatment of TB, and to determine the dosages and the most suitable method of administration to obtain benefit.  
In addition, VE showed a promising role in TB management as a result of its connection with oxidative balance. This statement is supported by laboratories findings. Hence, VE supplementation likely protects against TB progression in household contacts, against ATT-related organ toxicity and indirect complication of extrapulmonary TB such as kidney stone formation. Nevertheless, VE intake in excess could have adverse effects (as any vitamin), so it should not be subministrated indefinitely. More studies are required to profile which patients would benefit at best. No studies focus on positive sputum time-conversion.  
Our review suggests and encourages the use of vitamins in TB patients. In fact, their use may improve outcomes by helping both nutritionally and by interacting directly and/or indirectly with MTB. Several and more comprehensive trials are needed to reinforce these suggestions.  
Conceptualization, F.D.G.; methodology, F.D.G.; validation, A.S.; L.S.; F.P.; G.G. ([PERSON]); G.D.I.; writing--original draft preparation, A.R.; R.N., L.R.; V.T.; R.P.; S.C.; G.P.; C.P.; M.L.M.; I.E.; L.R.; S.S.; F.R., R.L., D.F.B.; supervision, F.P.; G.G. ([PERSON]); A.S.; L.S. All authors have read and agreed to the published version of the manuscript.