Source record
How prevalent is vitamin B12 deficiency among vegetarians?
Roman Pawlak, Scott Parrott, Sudha Raj, Diana Cullum-Dugan, Debbie Lucus (2013). Nutrition Reviews.
- Last reviewed
- Reviewer
- Editorial placeholder
- Status
- sample
Sample data. The figures and sources on this page are demonstration records showing how evidence will be presented. They are approximate and have not yet been through our review process. Read about how we will verify evidence.
Key findings
- Vitamin B12 deficiency is common among vegetarians and vegans who do not supplement or eat fortified foods, across all age groups studied.
Record
- Source type
- Systematic Review
- Study type
- Systematic Review
- Topics
- Nutrients to watch
- Geography
- Multiple countries
- Funding & conflicts
- Not recorded.
- Source quality
- Strong evidenceConsistent finding across many studies and populations.
Limitations
- Studies used different deficiency thresholds and markers.
Statistics we use from this source
- 52% (varies widely by study)Vegans with low B12 status in studies of unsupplemented groups
Claims this source supports
HealthStrong evidence
Vegans need vitamin B12 from supplements or fortified foods; without one, deficiency is common and can cause lasting harm.
Yes. This is the one nutrient a vegan diet cannot supply on its own. A cheap supplement solves it.
Claims this source challenges or complicates
HealthModerate evidence
A well-planned vegan diet is associated with lower risk of several chronic diseases, but the evidence does not show a clear difference in overall mortality, and poorly planned vegan diets carry nutritional risks.
It can be, if it is built on whole foods and covers a few nutrients. 'Vegan' on its own is not a health claim.