Health Reference LibraryFoods high in vitamin B12: UK portions and the plant diet gap
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
A portion of sardines supplies about five days of B12, salmon or beef about two, and eggs, milk and cheese cover the 1.5 microgram reference intake between them across a day. The gap is the plant based diet: no unfortified plant food contains B12, and fortified plant milks and yeast extracts vary so widely that anyone eating no animal foods needs a supplement or a careful daily count of fortified servings. Absorption from food also falls with age and with a low acid stomach, which is why older adults can be low on a good diet and why a blood test, not a food list, settles it.
How it works
How much you absorb matters as much as how much is on the plate. This is the one nutrient no unfortified plant food supplies. Meat, fish, eggs and dairy cover the reference intake many times over; a vegan diet gets B12 only from fortified foods, and fortified plant milks and yeast extracts vary widely, so anyone on a plant based diet needs a supplement or a careful daily count of fortified servings. Absorption from food also falls with age and with acid lowering stomach conditions, which is why older adults can be low on a good diet.
Effective dose
The reference intake is 1.5 micrograms a day; the table gives the richest everyday sources, starting with sardines, canned at about 8 micrograms for 100 g and salmon, cooked at about 3 micrograms for 100 g. Portion figures in the table are approximate, from the NHS and the NIH Office of Dietary Supplements food tables, and vary with variety, season and cooking; they are for planning a day, not for accounting.
Practical framework
Build the day from the table: two or three of the portions above usually reach the reference intake. If food will not close the gap, Nutri Tailor stocks [methylcobalamin capsules](/products/vitamin-b12-methylcobalamin-capsules), made in the UK; the dose page linked below says how much. To read your own result against the UK ranges, use the free blood test result interpreter. This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.
Common misconceptions
That one superfood does it: vitamin B12 adds up across the day from ordinary foods. That the figure on a packet is what you absorb: absorption depends on the form and the rest of the meal, as above. That a supplement is a substitute for the foods, which carry fibre, protein and other nutrients the capsule does not.
Forms compared
| Food | UK Portion | Vitamin B12 Per Portion |
|---|---|---|
Sources
- 2024. B vitamins and folic acid. NHS.
- NIH Office of Dietary Supplements 2025. Vitamin B12: Fact Sheet for Health Professionals. National Institutes of Health, Office of Dietary Supplements.