Vitamin B12 is a nutrient that helps keep the body’s nerve and blood cells healthy and helps make DNA, the genetic material in all cells.
Vitamin B12 is naturally absorbed by eating certain foods. Including B12-rich foods in your diet is therefore key to warding off the threat of a vitamin B12 deficiency.
A protein made by the stomach called intrinsic factor is needed to absorb vitamin B12 from food, however, certain underlying conditions impede this process.
Some may simply develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet.
As the NHS explains, a diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foods, such as those following a vegan diet or who have a generally very poor diet, can become deficient.
The underlying cause may be hard to identify initially because stores of vitamin B12 in the body can last around two to four years without being replenished, so it can take a long time for any problems to develop after a dietary change, notes the health site.
Certain stomach conditions or stomach operations can also prevent the absorption of enough vitamin B12.
“For example, a gastrectomy, a surgical procedure where part of your stomach is removed, increases your risk of developing a vitamin B12 deficiency,” explains the NHS.
Additionally, some conditions that affect your intestines can also stop you absorbing the necessary amount of vitamin B12.
For example, Crohn’s disease, a long-term condition that causes inflammation of the lining of the digestive system, can sometimes mean your body does not get enough vitamin B12, the NHS explains.
It is not just pre-existing conditions that can hamper the body’s ability to absorb vitamin B12.
Some types of medicine can lead to a reduction in the amount of vitamin B12 in your body.
“For example, proton pump inhibitors (PPIs), a medicine sometimes used to treat indigestion, can make a vitamin B12 deficiency worse,” explains the NHS.
How to treat a vitamin B12 deficiency
The wide range of causes means that the treatment for vitamin B12 or folate deficiency anaemia depends on what’s causing the condition.