Should patients on isoniazid-based anti‑tuberculosis therapy receive pyridoxine (vitamin B6) supplementation?

Vitamin B for patients on anti‑TB meds

• Recommendation: Give pyridoxine (vitamin B6) 25–50 mg daily with isoniazid to all patients at increased neuropathy risk; if neuropathy develops, increase to 100 mg daily. 1, 2, 1

• Who must receive B6 (give 25–50 mg/day from day 1):

  • Pregnant or breastfeeding (and breastfed infants of mothers on INH) 1, 2, 3
  • HIV infection, diabetes, alcoholism, malnutrition, chronic kidney disease, advanced age 1, 2, 1
  • Debilitated or poor nutritional intake; children with dietary risk or paresthesias 3

• Dose adjustments:

  • Established peripheral neuropathy: pyridoxine 100 mg/day with INH until symptoms resolve, then 25–50 mg/day 1, 2, 1
  • Breastfed infants of mothers on INH: give infant pyridoxine supplementation (typical pediatric practice: 1–2 mg/kg/day up to ~25 mg/day) 3

• Rationale tied to morbidity, mortality, QoL:

  • Prevents INH‑associated peripheral neuropathy, seizures, and neurotoxicity, which impair function and adherence, risking treatment failure and death. Multiple ATS/CDC/IDSA guidelines consistently endorse prophylaxis in at‑risk groups; the 2025 update strengthens to all patients on INH receiving 25–50 mg/day, aligning with safety and prevention priorities [4; corroborated by 1,2].
  • Biologic evidence shows INH lowers active B6 (PLP) levels rapidly; supplementation prevents deficiency and neuropathy 5.

• Practical algorithm:

  1. If any risk factor present (see list above) or per 2025 ATS/CDC/ERS/IDSA update: start pyridoxine 25–50 mg/day with INH the same day therapy begins [4; 1,2].
  2. Monitor for paresthesias, burning feet, weakness; if present, increase to 100 mg/day and assess for other causes; continue INH if tolerated 1, 2.
  3. In pregnancy/breastfeeding: ensure mother 25–50 mg/day; give infant pyridoxine supplement while breastfeeding if mother on INH 1, 3.
  4. Continue B6 for the entire duration of INH therapy; stop when INH stops.

• Pitfalls/caveats:

  • Do not rely on multivitamins alone—often <25 mg B6; prescribe dedicated pyridoxine 6.
  • Very high chronic B6 (>200 mg/day) may cause sensory neuropathy; stay within guideline doses (25–50 mg/day; 100 mg/day if symptomatic) [general safety; guideline dosing 1,2].
  • Children: routine prophylaxis is not universally mandated in all children, but give to breastfeeding infants and those with dietary risk or symptoms; many clinicians extend prophylaxis to high‑risk pediatric patients given safety and prevention benefits 3. The 2025 guideline table supports 25–50 mg/day with INH broadly, which can be applied with pediatric dosing considerations 4.

• Scope:

  • This applies to any regimen that includes isoniazid (e.g., HRZE/HR). Not required for rifampin‑only regimens unless other indications. 1, 2