B-Complex
Also known as: B vitamins, vitamin B complex
Recommended Dosage
1–1 capsule
B vitamins are a group of eight water-soluble vitamins that play essential roles in cellular metabolism, energy production, and nervous system function. While individual B vitamins have specific roles — B12 for nerve health, folate for DNA synthesis, B6 for neurotransmitter production — they often work synergistically. Methylated forms (methylfolate, methylcobalamin) are preferred as they bypass the MTHFR enzyme pathway that up to 40% of the population has reduced function in.
TL;DR: Group of essential vitamins for energy metabolism, nervous system function, and mood. Methylated forms preferred for MTHFR variants.
Evidence Rating: Grade B — Moderate Evidence
Some RCTs with positive results, or strong observational evidence. More research may refine our understanding.
Interaction Warnings
B6 >200mg/day can reduce levodopa effectiveness
Metformin depletes B12; supplement at least 1,000mcg/day
Reduce B12 absorption; supplement
⚠️ Important Notes
- Look for methylated forms (methylfolate, methylcobalamin)
- B2 may cause bright yellow urine — normal and harmless
- B6 >200mg/day long-term: peripheral neuropathy risk
Clinical Evidence (3 studies)
B vitamins and the brain: mechanisms, dose and efficacy
Kennedy DO (2016) — Nutrients
All B vitamins play essential roles in brain function; supplementation benefits even without deficiency
View on PubMedB vitamins reduced homocysteine by 26%
Clarke R et al. (2007) — Arch Intern Med
B12+B9+B6 reduced homocysteine; cardiac risk marker
View on PubMedB12 deficiency: neurological and cognitive consequences
O'Leary F & Samman S (2010) — Nutrients
Deficiency causes neurological damage; supplementation critical
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⚕️ Important Disclaimer
This information is for educational purposes only. It is not medical advice. Always consult a healthcare provider before starting any supplement regimen, especially if you take medications or have health conditions.
Evidence Stack does not sell supplements and has no affiliate relationships with supplement manufacturers.