Vitamin B12

What it is

It is a vitamin that the body needs. It is found mostly in foods made by animals. Meat, fish, eggs and dairy foods have it. Plants do not make this vitamin on their own.

What it does

It helps the body make red blood cells. It helps nerves in the body work well. It helps the body make new DNA in cells. It helps the body turn food into energy.

How much people need

• FDA Daily Value for Vitamin B12: 2.4 mcg. It is a reference amount used on Nutrition Facts labels, not a personal target. Source: US FDA.

Common myths

• Myth: Only meat and fish in food have this vitamin. Truth: Eggs and dairy foods also have this vitamin.
• Myth: Plant foods naturally contain vitamin B12. Truth: Plants do not make this vitamin. Plant sources are foods with B12 added, called fortified foods.

Sources and background

The sections on what it is, what it does and the myths are general background from NIH Office of Dietary Supplements: Vitamin B12 fact sheet, checked on 29 October 2026. The intake figures above carry their own sources.