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Vitamin B12 for adults 65 and over
Four micrograms a day, the same as any adult. This is the clearest case on the site where the published number is not the problem: an older adult can eat far more than 4 micrograms a day and still become deficient, because the absorption machinery fails before the diet does.
EFSA note on this row: the number does not change; absorption often does
These are published population reference values, not a diagnosis and not a prescription. A reference intake describes what covers a healthy group; it cannot tell you your own status, and no page can. Pregnancy, chronic illness, medicines and malabsorption all change the picture — take those questions to a doctor, midwife, pharmacist or dietitian.
The absorption problem, step by step
B12 in food is bound to protein. Stomach acid and pepsin have to release it; intrinsic factor made by the stomach lining has to bind it; and a specific receptor in the last part of the small intestine has to absorb the complex. Three steps, each of which can fail with age.
Atrophic gastritis — thinning of the stomach lining, with reduced acid and reduced intrinsic factor — becomes more common with age, and it breaks the first two steps. The result is food-bound B12 malabsorption: the vitamin is on the plate and does not get in. Pernicious anaemia, an autoimmune destruction of the intrinsic factor mechanism, does the same thing more completely.
Which is why free B12 often works when food does not
B12 in a supplement or in a fortified food is not bound to food protein, so it does not need the acid-and-pepsin step. That is the mechanism behind the common recommendation that older adults get part of their B12 from fortified foods or a supplement rather than relying on meat and dairy alone.
Where intrinsic factor itself is the problem, high-dose oral B12 can still work, because a small percentage crosses the gut wall by passive diffusion independently of the receptor. Injections remain the standard route in pernicious anaemia. Both are clinical decisions.
Medicines that make it more likely
Long-term metformin reduces B12 absorption and B12 levels are commonly monitored in people taking it. Long-term proton pump inhibitors and H2 blockers reduce stomach acid and so reduce the release of food-bound B12. Neither is a reason to stop a medicine on the strength of a web page — they are reasons to have B12 checked if symptoms appear.
Why catching it early matters most in this group
B12 deficiency causes a large-cell anaemia and a separate neurological syndrome: numbness and tingling in the feet and hands, unsteadiness, and cognitive and mood changes. In an older person those symptoms are easy to attribute to ageing, and the nerve damage can become permanent if the deficiency runs long enough.
It is also one of the reversible contributors to cognitive symptoms, which is why B12 is a standard test in that assessment. Unexplained tiredness, tingling, unsteadiness or memory change deserve a blood test rather than a supplement bought on a hunch.
How this compares with every other group
| Group | Reference value | Type | Note |
|---|---|---|---|
| Men 19-50 | 4 µg | AI | |
| Women 19-50 | 4 µg | AI | |
| Men 51 and over | 4 µg | AI | |
| Women 51 and over | 4 µg | AI | |
| Adults 65 and over | 4 µg | AI | the number does not change; absorption often does |
| Pregnancy | 4.5 µg | AI | |
| Breastfeeding | 5 µg | AI |
Ordinary food against the 4 µg figure for adults 65 and over
Top of this list: Veal liver, 59.9 µg in a 100 g serving (a small portion) — 1 496% of the 4 µg figure for adults 65 and over. One serving covers the whole day on its own.
| Food | Ordinary portion | Per portion | Share of the day |
|---|---|---|---|
| Veal liver | a small portion, 100 g | 59.9 µg | 1 496% |
| Mackerel | a fillet, 120 g | 22.8 µg | 570% |
| Canned sockeye salmon | half a tin, 100 g | 5.5 µg | 138% |
| Sardines | half a tin, 60 g | 5.36 µg | 134% |
| Trout | a fillet, 120 g | 4.93 µg | 123% |
| Salmon | a fillet, 120 g | 3.66 µg | 92% |
| Liverwurst spread | on one slice of bread, 25 g | 3.37 µg | 84% |
| Ground beef | a portion, 120 g | 3.28 µg | 82% |
| Canned tuna | a small tin, drained, 100 g | 2.55 µg | 64% |
| Cod | a fillet, 130 g | 1.36 µg | 34% |
| Greek yogurt | a small pot, 150 g | 1.12 µg | 28% |
| 2% milk | a glass, 200 g | 1.06 µg | 27% |
Portion sizes are ordinary household servings chosen for this table, not official reference portions, and the shortlist is an editorial one: everyday foods eaten in this region rather than the highest per-100 g entries in the database. A raw per-100 g ranking would be topped by dried herbs, drink powders and fortified breakfast cereals, which answers a different question. The composition data is American, so where US fortification practice differs from European practice the row carries a dagger and the reason. For the full per-100 g ranking of a nutrient, the food-data section of this site publishes one.
The whole nutrient, not just this group
The Vitamin B12 reference intake page carries the full age and sex table, the upper level, and what the value type means.
Related pages
Vitamin D for adults 65 and over
The same life stage, a different nutrient.
Protein for adults 65 and over
The same life stage, a different nutrient.
Sources: EFSA Dietary Reference Values · Regulation (EU) No 1169/2011, Annex XIII · USDA FoodData Central SR Legacy (food composition) · EFSA scientific opinion on dietary reference values for cobalamin, vitamin B12 (2015) · Regulation (EU) No 1169/2011, Annex XIII · checked 2026-09-06
Frequently asked questions
How much vitamin B12 do older adults need?
EFSA adequate intake is 4 micrograms a day, the same at every adult age. What changes with age is absorption, not the requirement.
Why do older adults become B12 deficient on a normal diet?
Because releasing B12 from food requires stomach acid and intrinsic factor, and both decline with atrophic gastritis, which becomes commoner with age. Fortified foods and supplements bypass that step.
Should older adults take a B12 supplement?
Guidance commonly suggests getting part of the intake from fortified foods or a supplement rather than food alone, because those forms do not need the acid step. Diagnosis and treatment of an actual deficiency belong with a clinician.
Turn a reference value into your own week
TempoLife adds up what you actually ate, so you can see how a real week sits against the figure on this page.