Ingredient guide

Vitamin B12: evidence, dose and safety

Vitamin B12 (cobalamin) is made only by bacteria and reaches people through animal foods or supplements. We use methylcobalamin; cyanocobalamin is the other common form.

At a glance

Strongest evidence: A Strong
Dose in our plans: 250 µg a day for adults
Safety checks: 0 situations and 0 medicine or supplement interactions, checked against your answers in every plan
Reviewed: Atrum Labs clinical team (MD, PhD), November 2026

Authorised EU health claim

Vitamin B12 contributes to the reduction of tiredness and fatigue.

What the research looked at

Each line is one body of research, graded A (strong) to D (weak). How we grade evidence. What each study measured is explained in your personal plan.

Grade	Who was studied	References
A	Adults with low B12	Devalia V et al. Br J Haematol 2014 (BSH cobalamin and folate guideline)
A	Vegans and vegetarians	Pawlak R et al. Eur J Clin Nutr 2014
B	Metformin users	Aroda VR et al. J Clin Endocrinol Metab 2016 (DPP/DPPOS)
B	Adults 65+	Allen LH, Am J Clin Nutr 2009 (review)
B	Adults 50+	IOM Dietary Reference Intakes 1998 (adults over 50 should get most B12 from supplements or fortified foods) Allen LH, Am J Clin Nutr 2009 (review)
C	Long-term PPI users	Lam JR et al. JAMA 2013

How much

Our plans usually use 250 µg a day for adults. The exact dose depends on your lab results, age and medicines.
Children's doses are set by age, and some ingredients are for adults only.

Products with Vitamin B12

Methyl-B12 1000 µg

Written and reviewed by the Atrum Labs clinical team (physician-scientists, MD, PhD) from our clinical knowledge base, version 0.2.0-draft. This page is general information, not medical advice. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle.

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