Vitamin B12
B vitamin essential for nerve function, red blood cell formation, and DNA synthesis. Found only in animal foods and fortified products.
Recommended Daily Allowance (RDA)
Daily Requirements by Life Stage 16 groups
| Life Stage | RDA / AI (µg/day) | Upper Limit (µg/day) |
|---|---|---|
| Children 1-3 years | 0.90 | — |
| Children 4-8 years | 1.2 | — |
| Males 9-13 years | 1.8 | — |
| Females 9-13 years | 1.8 | — |
| Males 14-18 years | — | — |
| Females 14-18 years | — | — |
| Males 19-30 years | 2.4 | — |
| Females 19-30 years | 2.4 | — |
| Males 31-50 years | — | — |
| Females 31-50 years | — | — |
| Males 51-70 years | — | — |
| Females 51-70 years | — | — |
| Males 70+ years | — | — |
| Females 70+ years | — | — |
| Pregnancy | 2.6 | — |
| Lactation | 2.8 | — |
Top Foods Highest in Vitamin B12
Amount per 100g serving. Values in µg per 100g.
Foods Highest in Vitamin B12 (Table)
| # | Food | Per 100g | Group |
|---|---|---|---|
| 1 | Mollusks, clam, mixed species, cooked, moist heat | 98.9 µg | Finfish and Shellfish Products |
| 2 | Beef, New Zealand, imported, variety meats and by-products l | 96.0 µg | Beef Products |
| 3 | Lamb, variety meats and by-products, liver, raw | 90.0 µg | Lamb, Veal, and Game Products |
| 4 | Lamb, variety meats and by-products, liver, cooked, pan-frie | 85.7 µg | Lamb, Veal, and Game Products |
| 5 | Veal, variety meats and by-products, liver, cooked, braised | 84.6 µg | Lamb, Veal, and Game Products |
| 6 | Beef, New Zealand, imported, variety meats and by-products, | 84.5 µg | Beef Products |
| 7 | Beef, variety meats and by-products, liver, cooked, pan-frie | 83.1 µg | Beef Products |
| 8 | Lamb, variety meats and by-products, kidneys, cooked, braise | 78.9 µg | Lamb, Veal, and Game Products |
| 9 | Lamb, variety meats and by-products, liver, cooked, braised | 76.5 µg | Lamb, Veal, and Game Products |
| 10 | Veal, variety meats and by-products, liver, cooked, pan-frie | 72.5 µg | Lamb, Veal, and Game Products |
| 11 | Moose, liver, braised (Alaska Native) | 71.0 µg | American Indian/Alaska Native Foods |
| 12 | Beef, variety meats and by-products, liver, cooked, braised | 70.6 µg | Beef Products |
| 13 | Veal, variety meats and by-products, liver, raw | 59.9 µg | Lamb, Veal, and Game Products |
| 14 | Beef, variety meats and by-products, liver, raw | 59.3 µg | Beef Products |
| 15 | Lamb, New Zealand, imported, liver, raw | 59.0 µg | Lamb, Veal, and Game Products |
| 16 | Lamb, New Zealand, imported, liver, cooked, soaked and fried | 57.5 µg | Lamb, Veal, and Game Products |
| 17 | Fish, whitefish, eggs (Alaska Native) | 56.4 µg | American Indian/Alaska Native Foods |
| 18 | Lamb, New Zealand, imported, kidney, cooked, soaked and frie | 55.6 µg | Lamb, Veal, and Game Products |
| 19 | Lamb, variety meats and by-products, kidneys, raw | 52.4 µg | Lamb, Veal, and Game Products |
| 20 | Lamb, New Zealand, imported, kidney, raw | 50.4 µg | Lamb, Veal, and Game Products |
Health Effects of Vitamin B12
Vitamin B12 is essential for DNA synthesis, red blood cell formation, neurological function, and methionine synthesis. It is required for myelin sheath integrity in the nervous system.
B12 deficiency causes megaloblastic anemia and progressive, potentially irreversible neurological damage (peripheral neuropathy, cognitive decline, dementia). Common in vegans, elderly, and those with pernicious anemia.
No adverse effects from high B12 intake; excess is excreted. No UL established. B12 injections are used therapeutically at doses thousands of times the RDA.
Absorption & Interactions
Complex absorption: requires gastric acid to release B12 from food proteins, intrinsic factor (from parietal cells) to bind B12, and specific receptors in the terminal ileum. Passive absorption (~1%) occurs at very high oral doses.
Estimated Vitamin B12 Adequacy by Country
Estimated from national food supply composition (FAO food balance sheets). Shows food supply availability relative to Estimated Average Requirement (EAR), not actual intake. Does not account for fortification, supplements, or distribution inequality.
Other Vitamins
Frequently Asked Questions
How much Vitamin B12 do I need per day?
Adult males need 2.4 µg/day and adult females need 2.4 µg/day.
Which food has the most Vitamin B12?
The food highest in Vitamin B12 is Mollusks, clam, mixed species, cooked, moist heat with 98.9 µg per 100g.
What does Vitamin B12 do in the body?
B vitamin essential for nerve function, red blood cell formation, and DNA synthesis. Found only in animal foods and fortified products.