Vitamin B12 is important for the proper formation of red blood cells, nerve function and DNA synthesis. It is naturally present in sardines and anchovies, beef, eggs, yoghurt, kefir, as well as certain fortified breakfast cereals. Our body does not synthesise it and so it must be introduced via our diet, absorbed in the stomach with the help of a protein known as intrinsic factor. A lack of vitamin B12 can cause neurological and psychiatric problems that might worsen if not addressed, leading to irreversible damage.
The recommended daily intake is approx. 2.4 mcg per day but increases during pregnancy and breast feeding to between 2.4 and 2.8 mcg.
Who is at risk of a vitamin B12 deficiency? Strict vegans, who avoid all animal products, may develop a vitamin B12 deficiency over time if they don’t take a daily supplement. Nevertheless, two thirds of vitamin B12 deficiency cases involve the elderly, either because less hydrochloric acid is secreted in the stomach, making absorption difficult, or because their dietary intake is insufficient.
What are the signs of a deficiency? When levels of this vitamin are low, various symptoms may occur, such as fatigue, weakness, constipation, loss of appetite or weight loss. Other symptoms include a difficulty keeping one’s balance, depression, confusion, dementia, poor memory and pain in the mouth or tongue. A B12 deficiency can also cause a form of anaemia called megaloblastic anaemia, which can also result from a lack of folic acid, or vitamin B9. In this case, pregnant women who are vegan should be particularly careful.
Also vulnerable to a vitamin B12 deficiency are coeliacs and those with Crohn’s disease, people who have lost a lot of weight or had gastrointestinal surgery, and those who take acid reflux drugs or metformin for diabetes. In these cases, it is important to verify the deficiency with a blood test and arrange a supplement as well as a suitable diet plan.