B vitamins are well known to be important for energy and metabolism however vitamin B12 is slightly different as it is more common to develop a deficiency. In this article we discuss all things B12, from its functions to where to find it in food, and who is most likely to become deficient.

What is vitamin B12 and why do we need it?

Vitamin B12 is a water soluble vitamin, which means our body cannot store it in our fat tissue, and we need to get it from our food every day. In addition, we can also make a small amount in our small intestine- thanks to our clever gut bugs!

It has many functions including:

  • Production of red blood cells which carry oxygen around our body
  • Regulation and maintenance of our nervous system
  • Formation of DNA and RNA which is the genetic material that builds our body
  • Helps to break down our food to release energy


Food containing vitamin B12

Vitamin B12 is mostly found in animal products such as meat, dairy, eggs, cheese and fish. Some foods such as soy milk and vitamin drinks are also often fortified with vitamin B12.

While it is only required in very small amounts every day, if you do not eat enough of these foods, it is easy to become low or deficient in vitamin B12.


Who is at risk of deficiency?

Vitamin B12 deficiency is also known as megoblastic anaemia and can be quite common in people who are vegan and vegetarian, as they consume few or no animal products in their diet. Those with coeliac disease or with inflammatory bowel disorders such as Crohns disease may also be at risk of vitamin B12 deficiency due to damage to the intestine, preventing the absorption of B12.

Symptoms of megoblastic anaemia include:

  • Extreme fatigue and tiredness as not enough red blood cells are being made to carry oxygen around your body
  • Shortness of breath
  • Pale skin
  • Feelings of pins and needles
  • Poor mental function
  • Depression
  • Disturbed Vision

Another type of vitamin B12 deficiency is called pernicious anaemia, which is very rare and much more severe than megoblastic anaemia. Pernicious anaemia is an autoimmune disorder and disables the stomach from absorbing B12 into the body. This is generally treated with B12 injections at a GP.


Who needs to take a supplement?

Vegans are generally recommended to supplement with vitamin B12, particularly if they do not consume many fortified foods such as plant foods or nutritional yeast. Vegetarians who also do not consume much cheese or eggs are also advised to supplement with vitamin B12 to ensure they are receiving an adequate amount every day.

 Furthermore, those with medical conditions such as Crohn’s or coeliac disease may be advised by their doctors to supplement with B12 depending on their condition.

Sona Vitamin B12 – Methylcobalamin 500μg contains the active enzyme form of vitamin B12, which the body can retain for longer. This supplement contributes to the normal energy metabolism, nervous and immune systems. It may also help to boost energy levels and enhance the function of the immune system.





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Seal, E.C., Metz, J., Flicker, L. and Melny, J., 2002. A randomized, double‐blind, placebo‐controlled study of oral vitamin B12 supplementation in older patients with subnormal or borderline serum vitamin B12 concentrations. Journal of the American Geriatrics Society50(1), pp.146-151.


Stabler, S.P., 2013. Vitamin B12 deficiency. New England Journal of Medicine368(2), pp.149-160.