Vitamin B12 deficiency occurs when the body lacks the vitamin. B12 is best gained through diet, and one reason a person may not get enough is B12 is primarily found in animal food sources. This means vegans and vegetarians, unless they’re getting their vitamin B12 from plant sources, could be at risk. However another cause of vitamin B12 deficiency is pernicious anaemia.
This condition is the most common cause of vitamin B12 deficiency, and develops if the body can’t absorb vitamin B12 from food as it normally would.
Bupa explains: “Pernicious anaemia is an autoimmune disease, caused by antibodies from your immune system attacking your own body tissue, which it mistakes as being foreign. This causes inflammation in the lining of your stomach.
“Normally, a protein known as intrinsic factor, which is made in your stomach, attaches to the vitamin B12 released from the food you have eaten and then carries the vitamin through your bowel wall into your blood.
“If you have pernicious anaemia, the stomach cells that produce intrinsic factor may be damaged, meaning vitamin B12 can no longer be absorbed and a deficiency develops, leading to anaemia.”
The exact reasons why pernicious anaemia develops are not fun understood, but does tend to affect women more than men and can run in families.
Vitamin b12 deficiency can lead to serious health complications if left untreated, which affect the heart and movement, so recognising symptoms of the condition is very important.
Symptoms of vitamin B12
Bupa lists six signs to look out for. If you experience any of these, see your GP:
- Feeling very tired
- Breathlessness even after a little exercise
- Heart palpitations
- A reduced appetite
- A sore mouth and tongue
It adds: “If you have vitamin B12 deficiency you may also look pale or jaundiced (have a yellowy tinge to your skin and the whites of your eyes).”
Vitamin B12 is responsible for red blood cell production and keeping the nervous system healthy, so a lack of B12 may also cause symptoms related to the nerves.
Movement and sensation in various parts of the body may be affected, with pins and needles and sensitivity to touch associated signs.
Treatment of pernicious anaemia
If a person if not getting enough vitamin B12 from their diet they may be advised by a GP to eat more food fortified with vitamin B12 or to take regular supplements.
Vitamin B12 injections may also be recommended, and for those with pernicious anaemia, injections may be required for the rest of their lives.
Experts say adults aged 19 to 64 require around 1.5 micrograms (mg) a day of vitamin B12, and unless you have pernicious anaemia, you should be able to get this through your diet.
Certain foods contain vitamin B12 and Harvard Health Publishing, part of Harvard Medical School, offers the “A list of B12 foods” on its website.