The most common cause of this deficiency is pernicious anaemia – here’s what you should know
A well-known GP has shed light on an overlooked deficiency and its symptoms, which may help you spot it. His thoughts come as just 6% of people under 60 and 20% of those over 60 are affected by the issue, with an additional 11% being people on vegan diets, as per NHS figures.
Dr Suraj Kukadia, also known as Dr Sooj, said in a recent TikTok: “What happens in vitamin B12 deficiency? There are many symptoms associated with it, and it can be really, really non-specific, but it does include things like feeling fatigued and tired all the time.
“You can get pins and needles, confusion, memory problems. It can also cause muscle weakness and a really, really sore and inflamed tongue.”
Official NHS advice also warns that vitamin B12 deficiency may cause shortness of breath, indigestion, loss of appetite, palpitations, and diarrhoea. While some people develop the deficiency due to a lack of B12 in their diet, the most common cause is an autoimmune condition called pernicious anaemia.
This condition essentially causes the immune system to attack cells in the stomach, triggering a reaction that prevents the body from absorbing vitamin B12. The exact cause of this remains unclear, but it is more frequently observed in women around age 60, people with a family history of the issue, and those with other autoimmune conditions, such as vitiligo.
“Most cases of vitamin B12 and folate deficiency can be easily treated with injections or tablets to replace the missing vitamins,” the NHS advises. “Vitamin B12 supplements are usually given by injection at first.
“Then, depending on whether your B12 deficiency is related to your diet, you’ll either require B12 tablets between meals or regular injections. Treatments may last until your vitamin B12 levels have improved or you may need treatment for the rest of your life.”
Anyone concerned about their health is encouraged to consult a GP and seek a prompt diagnosis. While many symptoms improve with treatment, some issues caused by the deficiency may be ‘irreversible’.
For more information, visit the NHS website here.
Good food sources of vitamin B12
Vitamin B12 is involved in numerous essential bodily processes, including the production of red blood cells and maintaining the nervous system. Adults (ages 19 to 64) need about 1.5 micrograms of vitamin B12 per day.
Sources of vitamin B12 include:
- Meat
- Fish
- Milk
- Cheese
- Eggs
- Some fortified breakfast cereals
If you consume meat, fish, or dairy products, your diet should provide enough vitamin B12. However, since vitamin B12 is not naturally present in foods like fruits, vegetables, and grains, vegans might not obtain enough of it.













