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Types of Vitamin B12: Forms & Bioavailability

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest For
MethylcobalaminHighGeneral supplementation — bioactive coenzyme form, no conversion needed, supports methylation
CyanocobalaminModerateCost-effective option — synthetic form, well-studied, requires conversion to active form
HydroxocobalaminHighInjection and sustained levels — longer retention time in the body, used clinically for deficiency
AdenosylcobalaminHighMitochondrial energy support — active coenzyme form used directly in the citric acid cycle

Methylcobalamin

Bioavailability: High. Best for: General supplementation — bioactive coenzyme form, no conversion needed, supports methylation.

Cyanocobalamin

Bioavailability: Moderate. Best for: Cost-effective option — synthetic form, well-studied, requires conversion to active form.

Hydroxocobalamin

Bioavailability: High. Best for: Injection and sustained levels — longer retention time in the body, used clinically for deficiency.

Adenosylcobalamin

Bioavailability: High. Best for: Mitochondrial energy support — active coenzyme form used directly in the citric acid cycle.

Full Vitamin B12 Guide

References

  1. (). The Many Faces of Cobalamin (Vitamin B12) Deficiency. Mayo Clinic Proceedings: Innovations, Quality & Outcomes. DOI
  2. (). Cognitive impairment and vitamin B12: a review. International Psychogeriatrics. DOI
  3. (). Homocysteine-lowering interventions for preventing cardiovascular events. Cochrane Database of Systematic Reviews. DOI
  4. (). Homocysteine-lowering by B vitamins slows the rate of accelerated brain atrophy in mild cognitive impairment: a randomized controlled trial. PLoS ONE. DOI