One standard 8.4 oz Red Bull contains around 5 micrograms of vitamin B12, with larger cans delivering even more per serving.

One large chicken egg contains around 0.6 micrograms of vitamin B12, roughly one quarter of the daily amount recommended for healthy adults.

One cup of cow’s milk usually provides around 1.1 micrograms of vitamin B12, which covers close to half of an adult’s daily need.

Most healthy adults need about 2.4 micrograms of vitamin B12 per day, with a small increase during pregnancy and breastfeeding.

One healthy adult usually needs about 2.4 micrograms of vitamin B12 a day, with higher B12 recommendations during pregnancy and breastfeeding.

Most standard vitamin B12 injections contain 1,000 micrograms of B12 per dose, though some shots deliver 100 to 500 micrograms instead.

Each Metanx capsule contains 2 mg of methylcobalamin vitamin B12, and most adults take two capsules daily under medical supervision.

One large egg usually contains about 0.5 micrograms of vitamin B12, giving roughly one fifth of an adult’s daily need.

Most healthy adults can safely take up to 1,000–2,000 mcg of vitamin B12 daily, though many only need small doses to meet their needs.

Most adults use 25–1,000 mcg of B12 methylcobalamin daily, while official guidelines still base needs on about 2–4 mcg of vitamin B12 per day.