Vitamin B12
Affiliate link: we may earn a commission at no extra cost to you. Disclosures
Vitamin B12. Essential cobalamin for methylation, red blood cell formation, and myelin maintenance.
How it works. Cofactor for methionine synthase (methylation cycle) and methylmalonyl-CoA mutase (fatty acid metabolism).
What the research supports. 3 graded claims. Strongest: Resolves megaloblastic anemia (strong).
How much to take. Typical dose: 500–1000 mcg oral. Morning.
Side effects and interactions. 2 medication interactions listed. No serious side effects listed at normal doses.
Stacking. Pairs well with Folate.
Forms. 3 forms. Pick one to open its profile.
Key studies. 10 studies cited. The strongest are listed with links to PubMed.
Community. Experiences from people who have tried Vitamin B12. Anecdotes are not medical advice.
Vitamin B12. Essential cobalamin for methylation, red blood cell formation, and myelin maintenance.
What it is
Water-soluble cobalt-containing vitamin found almost exclusively in animal products; deficiency is common in vegans and older adults.
Also called
Food sources
Goals
How it works
Cofactor for methionine synthase (methylation cycle) and methylmalonyl-CoA mutase (fatty acid metabolism).
Pathways
- Methylation (homocysteine → methionine)
- Myelin synthesis
Effects
- ↓Homocysteine decreases
- +Red blood cell formation supports
- +Cognitive function (if deficient) supports
What the research supports
Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.
As an Amazon Associate I earn from qualifying purchases. Look for USP, NSF or Informed Sport seals before you buy.
Side effects & interactions
Medication interactions
Long-term metformin lowers B12 — monitor levels.
Reduce absorption of dietary B12.
Check any supplement–medication combination with your pharmacist before starting.
Combines with
Pairs well
- FolateMethylation cycle partners.
Key studies
10 studies cited in total.
Opens current human and preclinical literature matching Vitamin B12 and "Resolves megaloblastic anemia". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Vitamin B12 and "Reverses neuropathy in deficient patients". Filter by RCT, meta-analysis, or year on the results page.
Opens current human and preclinical literature matching Vitamin B12 and "Improves fatigue". Filter by RCT, meta-analysis, or year on the results page.
Discussion
Loading discussion…