Dosage Lookup

Vitamin B12

3.4

Moderate

consensus

1,000 mcg daily of methylcobalamin for general supplementation. Attia uses B12 alongside methylfolate to target homocysteine below 9. Hyman recommends testing methylmalonic acid and homocysteine levels to guide dosing — higher doses may be needed for those with malabsorption, MTHFR variants, or on PPIs.

Based on expert consensus data from publicly available videos, not medical advice. Always consult your healthcare provider before starting, stopping, or changing any supplement.

Consensus Protocol

Dosage

  • 1,000 mcg daily of methylcobalamin for general supplementation
  • Attia uses B12 alongside methylfolate to target homocysteine below 9
  • Hyman recommends testing methylmalonic acid and homocysteine levels to guide dosing — higher doses may be needed for those with malabsorption, MTHFR variants, or on PPIs

Form

  • Methylcobalamin (methylated B12) is preferred over cyanocobalamin by all experts who specify a form
  • Attia and Patrick both specifically recommend methylcobalamin
  • Hyman recommends methylated B-vitamins broadly
  • Sublingual or injection forms may be necessary for those with gut absorption issues

Timing

  • Take with meals
  • Often taken as part of a B-complex or alongside methylfolate for optimal methylation support
  • Attia pairs B12 with methylfolate in his daily protocol

Notes

  • Test homocysteine and methylmalonic acid (MMA) levels before supplementing — these are more sensitive markers of functional B12 status than serum B12 alone
  • Consider genetic testing for MTHFR and FUT2 polymorphisms (Patrick)
  • Those on PPIs, metformin, the elderly, vegans, and people with celiac disease or gut issues are at highest risk for deficiency
  • B12 is water-soluble, so toxicity risk is very low even at high doses

Expert Positions

Andrew Huberman
Andrew Huberman
Mentions in Context of Mental Health
Peter Attia
Peter Attia
Includes in Personal Protocol
Rhonda Patrick
Rhonda Patrick
Recommends for MTHFR Variants
Bryan Johnson
Bryan Johnson
No Direct Coverage
Mark Hyman
Mark Hyman
Strongly Recommends as Essential

What Each Expert Says

Andrew Huberman
Andrew Huberman
Mentions in Context of Mental Health

Huberman's coverage of B12 is limited and indirect. His most relevant mention comes in a guest episode with Dr. Chris Palmer on metabolic psychiatry, where B12 is discussed alongside folate and iron as critical vitamins for mitochondrial function with direct impact on mental health. Dr. Palmer highlights that deficiencies in these nutrients, particularly in certain populations, are linked to neurological and psychiatric symptoms. B12 is not part of Huberman's frequently discussed foundational supplement stack.

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More on Vitamin B12

Consensus Score Which Form? When to Take Check Your Stack

Common Questions

How much Vitamin B12 should you take?

1,000 mcg daily of methylcobalamin for general supplementation. Attia uses B12 alongside methylfolate to target homocysteine below 9. Hyman recommends testing methylmalonic acid and homocysteine levels to guide dosing — higher doses may be needed for those with malabsorption, MTHFR variants, or on PPIs.

What form of Vitamin B12 is best?

Methylcobalamin (methylated B12) is preferred over cyanocobalamin by all experts who specify a form. Attia and Patrick both specifically recommend methylcobalamin. Hyman recommends methylated B-vitamins broadly. Sublingual or injection forms may be necessary for those with gut absorption issues.

When should you take Vitamin B12?

Take with meals. Often taken as part of a B-complex or alongside methylfolate for optimal methylation support. Attia pairs B12 with methylfolate in his daily protocol.

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