General Dosage
500-2,000 mcg daily of methylcobalamin, sublingual or oral
Maximum dose: No established upper limit (water-soluble, excess excreted); doses up to 5,000 mcg daily are commonly used without adverse effects
Vitamin B12 Dosage Guide
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Dosage Recommendations
General recommendation: 500-2,000 mcg daily of methylcobalamin, sublingual or oral
Timing: Morning or early afternoon for energy support; avoid late evening
Dosage by Condition
| Condition | Recommended Dose | Evidence |
|---|---|---|
| General maintenance | 500-1,000 mcg daily | Strong |
| Deficiency correction | 1,000-2,000 mcg daily for 8-12 weeks | Strong |
| Cognitive support (elderly) | 1,000 mcg daily | Moderate |
| Homocysteine reduction | 500-1,000 mcg daily with folate and B6 | Strong |
Upper limit: No established upper limit (water-soluble, excess excreted); doses up to 5,000 mcg daily are commonly used without adverse effects
Timing & Absorption
Morning or early afternoon for energy support; avoid late evening
Can be taken with or without food.
References
- Wolffenbuttel BHR, Wouters HJCM, Heiner-Fokkema MR, van der Klauw MM (2019). The Many Faces of Cobalamin (Vitamin B12) Deficiency. Mayo Clinic Proceedings: Innovations, Quality & Outcomes. DOI PubMed
- Moore E, Mander A, Ames D, et al. (2012). Cognitive impairment and vitamin B12: a review. International Psychogeriatrics. DOI PubMed
- Martí-Carvajal AJ, Solà I, Lathyris D, Dayer M (2017). Homocysteine-lowering interventions for preventing cardiovascular events. Cochrane Database of Systematic Reviews. DOI PubMed
- Smith AD, Smith SM, de Jager CA, et al. (2010). Homocysteine-lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment: a randomized controlled trial. PLoS ONE. DOI PubMed