Vitamin B12

Working together with another B vitamin, folate, vitamin B12 is involved with making red blood cells and maintaining a healthy nervous system. It’s a water-soluble vitamin and should be eaten every day.

Where can I get it?

Only found in animal foods, not plant foods, vitamin B12 is stored by your body, in the liver. Animal liver* contains the most vitamin B12 - meat, fish, eggs, milk and dairy products contain less but are generally eaten more often so they’re good sources.

*Pregnant women should avoid eating liver because it contains high amounts of vitamin A.

How much should I eat?

Because vitamin B12 is stored in your liver, stores built up during childhood can last as long as 30 years. However, if a child has a low intake of vitamin B12 and never builds up a good store, he or she can ‘run out’ within three or four years.

Elderly people are most at risk of vitamin B12 deficiency because their stores – which would have been adequate through most of their life - run low as they age. If this happens, they risk anaemia and even heart disease or permanent nerve damage.

Vitamin B12 deficiency is very serious, so speak to a doctor if you think your dietary intake is inadequate.

It’s recommended that we eat around 0.0015mg (1.5 micrograms) a day, which is enough to keep stores topped up in case of occasional low intakes. This is easily achieved by eating varied, balanced diet and, because it’s very safe, no upper limit of the naturally occurring form has been set.

There isn't enough evidence to know what the effects might be of taking high doses of vitamin B12 supplements each day but the Food Standards Agency says that taking up to 2mg in supplements a day is unlikely to cause any harm.

A serving of smoked haddock contains almost twice the recommended daily intake (2.8 micrograms); a piece of cheddar cheese provides around half (0.7 micrograms).

What does it do?

This vitamin is needed for a healthy nervous system and to help make red blood cells. It’s used to convert food into energy and to help process and use another B vitamin, folate.