Did You Know About Our Online Doctor Service?

Vitamin B12

Vitamin B12

Vitamin B12 (also known as cyanocobalamin) is one of eight vitamins in the B vitamin family. It’s important to get enough vitamin B12 as it helps keep the body’s nerves and blood cells healthy.

Where do I find vitamin B12?

  • Lots of animal products contain vitamin B12 including meat, salmon, cheese, milk, eggs and shellfish. Some breakfast cereals are fortified with vitamin B12.
  • Your daily intake of vitamin B12 should be around 0.0015mg.
  • Most people who eat meat, fish and dairy products should get sufficient amounts of vitamin B12 from their diets but vegans may need to eat vitamin B12-fortified foods or take supplements as B12 is not found in fruit, vegetables or grains.
  • Vitamin B12 is often found in multivitamins. It is best absorbed by the body when taken along with other B vitamins such as riboflavin and vitamin B6.

Why do I need vitamin B12?

Vitamin B12 helps our body’s release energy from the food we eat. It also supports the production of red blood cells and keeps the nervous system healthy. In addition, vitamin B12 aids the production of DNA (the genetic material in our cells).

Many claims are made about the benefits of vitamin B12 including the idea that it can be used to help treat dementia. People with dementia often have high levels of an amino acid called homocysteine in their blood. Vitamin B12, together with folic acid and vitamin B6 appears to lower homocysteine levels. More research is needed in this area.

How will I know if I am lacking in vitamin B12?

If you lack vitamin B12 you may become anaemic. Signs of a deficiency include tiredness, weakness, constipation, mouth sores, loss of appetite and weight loss. In addition, a lack of vitamin B12 can cause a loss of balance and numbness or tingling in your arms, hands and feet. Other problems caused by a B12 deficiency include confusion and poor memory.

People who have had gastrointestinal surgery (such as weight loss surgery) or those with digestive disorders such as celiac disease or Crohn’s disease may have problems absorbing enough vitamin B12. Vegans may also lack this vitamin.

Some medications can interfere with the absorption of vitamin B12 including some diabetes treatments. It is best to speak to your doctor if you fall into this category.

Alcoholism is also associated with low levels of vitamin B12.

If you are anaemic your doctor will check if you are lacking in vitamin B12. Depending on the level of the deficiency you may be treated with vitamin B12 injections or supplements.

Can vitamin B12 ever be harmful?

Vitamin B12 is generally considered to be safe and there is insufficient evidence to suggest otherwise. According to NHS Choices taking a vitamin B12 supplement of 2mg or less per day is unlikely to cause any harm.

Vitamin B12 supplements can however, interfere with some medications including some antibiotics, medicines for peptic ulcers, and some diabetes treatments. If you are taking medication it is best to check with your doctor before taking supplements.