Vitamin B12 - Cobalamin

Information written and reviewed by Certified Doctors.

Vitamin B12 is involved in:

  • making red blood cells and keeping the nervous system healthy
  • releasing energy from food
  • using folic acid

A lack of vitamin B12 could lead to vitamin B12 deficiency anaemia .

Good sources of vitamin B12

Good sources include:

  • meat
  • salmon
  • cod
  • milk
  • cheese
  • eggs
  • some fortified breakfast cereals

How much vitamin B12 do I need?

Adults (19-64 years) need about 1.5mcg a day of vitamin B12.

If you eat meat, fish or dairy foods, you should be able to get enough vitamin B12 from your diet.

But as vitamin B12 isn't found naturally in foods such as fruit, vegetables and grains, vegans may not get enough of it.

Read about the vegan diet for nutrition information and advice.

What happens if I take too much vitamin B12?

There's not enough evidence to show what the effects may be of taking high doses of vitamin B12 supplements each day.

What does the Department of Health advise?

You should be able to get all the vitamin B12 you need by eating a varied and balanced diet. If you take vitamin B12 supplements, don't take too much as this could be harmful.

Taking 2mg or less a day of vitamin B12 in supplements is unlikely to cause any harm.

Content supplied by NHS Choices