Why do vegans need B12 from supplements?
Vitamin B12 is made by microorganisms and found naturally only in animal foods. Vegans therefore rely on fortified foods or supplements. The NIH notes that vegetarians and vegans have a higher risk of deficiency, and that fortified foods and supplements can substantially reduce it.
Why are supplement doses so much higher than the RDA?
The adult RDA is 2.4 µg a day (2.6 µg in pregnancy, 2.8 µg while breastfeeding). B12 absorption depends on intrinsic factor, which saturates quickly:
| Dose taken at once | Approximate absorption |
|---|
| 1 to 2 µg or less | about 50% |
| 500 µg | about 2% |
| 1 000 µg | about 1.3% |
That is why a large tablet is normal. The NIH has set no upper limit for B12 because toxicity risk is low, although Vegan Health advises seeing a physician before staying above 1 000 µg a day long term.
What regimens do vegan dietitians use?
Guidance varies a little between sources, but the patterns are consistent:
- Daily, split: small doses taken more than once a day. Vegan Health's example is half a 10 µg tablet (5 µg) twice a day, at least four hours apart, which it says matches EFSA's adequate intake of 4 µg a day.
- Weekly: 2 500 µg once a week (for example five 500 µg tablets), which Vegan Health also says matches the EFSA recommendation.
Vegan Health describes its amounts as minimums and notes that smaller, more frequent doses are usually more economical.
Choose one pattern you will keep up. A daily tablet is easiest to remember; a weekly high dose suits people who forget.
Can a multivitamin do the job?
Often yes. As of October 2026, per daily dose:
- Dis-Chem Gold Multivitamin Supreme Active has 10 µg B12 (R3.33 a day).
- Viridian High Five has 50 µg (R7.50 a day).
- Solgar Formula VM-2000 has 100 µg per two tablets (R16.63 a day).
Because absorption from a single dose is limited, whether one daily multivitamin covers your needs depends on its B12 content and your other sources, so check with a dietitian or use the weekly option as well. Single-nutrient B12 products were not in our October 2026 price sample, so we do not quote a Rand figure for them. Compare options in the best multivitamin in South Africa and on our best multivitamin page.
Which other sources count?
Look for B12 on the label of fortified plant milks, breakfast cereals and nutritional yeast, but do not rely on them alone unless you check amounts. Seaweed, spirulina and unfortified fermented foods are not reliable sources.
Who should be extra careful?
- Pregnant or breastfeeding vegans should work with a dietitian, because a baby's stores depend on the mother's.
- Adults over 50 absorb B12 from food less well and are advised to use fortified foods or supplements.
- People taking some medicines that reduce absorption should ask a pharmacist.
See a doctor if you notice numbness or tingling, persistent tiredness, or memory problems; a blood test can confirm deficiency. For the wider picture, read what vegan athletes need and vitamin D and B12 over 60.
Products mentioned
| Product | Size | Price (source, date) | Servings | R per serving | Sweeteners |
|---|
| Dis-Chem Gold Multivitamin Supreme Active 60 softgels | 60 softgels | R200 (Dis-Chem Living Fit, 2026-10) | 60 | R3.33 | glycerol (132 mg sugar source per capsule) |
| Viridian High Five Multivitamin and Mineral 90 capsules | 90 capsules | R675 (Faithful to Nature, 2026-10) | 90 | R7.50 | none |
| Solgar Formula VM-2000 60 tablets | 60 tablets | R499 (Faithful to Nature, 2026-10) | 30 | R16.63 | mannitol, maltodextrin |
Educational information, not medical advice. Speak to a doctor, pharmacist or registered dietitian before using supplements if you are pregnant or breastfeeding, under 18, taking medication, or living with kidney, liver or heart disease. Prices were observed in October 2026 and are not offers.