The recommended daily amount of vitamin B12 for most adults is 2.4 micrograms (mcg). This amount is generally sufficient for healthy adults to maintain normal levels through diet or supplements
. Specific groups may require slightly higher amounts:
- Pregnant women: about 2.6 mcg/day
- Breastfeeding women: about 2.8 mcg/day
- Older adults and people with absorption issues may need supplements or higher doses
Vitamin B12 is found naturally in animal products like meat, fish, poultry, eggs, and dairy. Vegetarians and vegans are advised to consume fortified foods or take supplements to meet their needs
. There is no established upper limit for vitamin B12 intake because excess amounts are generally excreted in urine and the vitamin is considered safe even at high doses
. However, high-dose supplements (e.g., 500 to 5,000 mcg) are typically reserved for people diagnosed with a deficiency or absorption problems, often under medical supervision
. In summary:
- General adult daily intake: 2.4 mcg
- Pregnant/lactating women: 2.6–2.8 mcg
- Supplement doses vary widely, with no known toxicity at high levels
- Those at risk of deficiency (vegetarians, older adults, certain medical conditions) may require supplements or higher doses
