NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated July 13, 2026

Vitamin B12

Vitamin ·Exploratory record · not publication-reviewed ·Updated July 13, 2026

Essential for nerve function, red blood cell formation, DNA synthesis, and methylation. Common deficiency in vegans and older adults due to absorption issues.

Evidence tier
Strong
Indexed sources
20 2005–2025
Interactions
0
Cost / month
$0.90 budget
Read the sources → Compare profiles
Publication status

Exploratory record, not a reviewed medical publication.

See the editorial and medical-review policies for the publication gate.

This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.

In short

What the research says.

A quick, data-only summary. The full evidence, dosing, and sources are below.

Vitamin B12 is a vitamin most often used for energy production (only in deficiency; no benefit if b12-sufficient), nerve health, red blood cell formation. NutriStack rates the overall evidence as strong. A typical adult dose is 1,000–5,000 mcg daily, commonly taken as methylcobalamin or hydroxocobalamin (better retention than cyanocobalamin). This profile indexes 20 sources.

What it's good for
  • Energy production (only in deficiency; no benefit if B12-sufficient)2,4
  • Nerve health19
  • Red blood cell formation19
  • Methylation support
  • Cognitive function6,9
What to watch for
  • Very safe even at high doses
  • Rare acne-like skin reaction
  • Leber's hereditary optic neuropathy13,17

The bottom line

Evidence rating strong. Most-documented uses: energy production (only in deficiency; no benefit if b12-sufficient), nerve health, red blood cell formation. 20 sources indexed (2005–2025), with 0 interaction records on file.

The science

How it works, mechanistically.

Core mechanism

As methylcobalamin, cofactor for methionine synthase (converts homocysteine to methionine, generating SAMe for methylation). As adenosylcobalamin, cofactor for methylmalonyl-CoA mutase in the mitochondrial energy pathway.19,13

Class
B Vitamin
Found in food
Liver, Clams, Beef
Low-status signs
Fatigue, Numbness/tingling
Dosing

Dosing & protocol.

Common range
1,000–5,000 mcg daily
Recommended form
Methylcobalamin or hydroxocobalamin (better retention than cyanocobalamin)

Sublingual forms bypass potential absorption issues; take in the morning16,2

Cost

What it actually costs.

Real-world pricing across three quality tiers. Assumes Cyanocobalamin.

BudgetBest value
$0.90 /mo
$0.03 per dose
Mid
$2.40 /mo
$0.08 per dose
Premium
$5.40 /mo
$0.18 per dose

Assumes about 500-1,000 mcg/day. Standard oral B12 is inexpensive; premium pricing usually reflects lozenges, sprays, or boutique branding rather than meaningfully better economics. Updated 2026-04-02.

From food

The same dose, as food.

How much you'd eat to match a supplemental dose.

1,000 mcg vitamin B12
Far more than a normal food-based daily intake; several servings of clams or liver would still be much lower

Supplemental B12 doses are pharmacologic compared with normal food intake.

2.4 mcg vitamin B12
About 3 ounces salmon, trout, or beef, or 2 eggs plus dairy

Food can cover the RDA easily if animal foods are eaten regularly.

Safety

Full safety detail.

Side effects

  • Very safe even at high doses
  • Rare acne-like skin reaction

Contraindications

  • Leber's hereditary optic neuropathy13,17
Sources

Sources, by evidence tier.

Numbered references. Citations throughout the page link here.

Meta-analyses & systematic reviews

12

Randomized controlled trials

1
  • 13Methylcobalamin treatment for peripheral neuropathy: a dose-finding and efficacy trialKuwabara S, Nakazawa R, Azuma N et al. · Intern Med · 2019

Reviews & position papers

3

Observational studies

2
  • 17Metformin-induced vitamin B12 deficiency presenting as peripheral neuropathy: a case-control studyAhmed MA, Muntingh G, Rheeder P · Diabetes Metab Res Rev · 2016
  • 18Vitamin B12 status and rate of brain volume loss in community-dwelling elderly: a 5-year follow-up studyVogiatzoglou A, Refsum H, Johnston C et al. · Neurology · 2008

Reference material

2
FAQ

Common questions.

Quick answers about Vitamin B12, drawn from the data on this page.

What is Vitamin B12?

Essential for nerve function, red blood cell formation, DNA synthesis, and methylation. Common deficiency in vegans and older adults due to absorption issues.

What is Vitamin B12 used for?

Commonly cited benefits of Vitamin B12 include: Energy production (only in deficiency; no benefit if B12-sufficient); Nerve health; Red blood cell formation; Methylation support; Cognitive function. NutriStack rates the overall evidence as strong.

What is a typical dose of Vitamin B12?

A typical adult dose of Vitamin B12 is 1,000–5,000 mcg daily. The commonly recommended form is Methylcobalamin or hydroxocobalamin (better retention than cyanocobalamin). These are general ranges, not personalized advice; confirm the right dose with a clinician.

What are the side effects of Vitamin B12?

Reported side effects include very safe even at high doses, rare acne-like skin reaction. This is educational information; check with a healthcare professional before use.

How strong is the evidence for Vitamin B12?

NutriStack rates this as Strong, meaning multiple high-quality meta-analyses or systematic reviews converge on the same finding. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.

Use this with your stack

Vitamin B12 in NutriStack.

Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.

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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.