Could you have a vitamin B12 deficiency?

Causes, symptoms, and treatment options

Senior woman having headache

As you age, it's even more important to eat a healthy diet. Vitamin B12 deficiency is more common in older people, affecting around one-in-20 people aged 65 to 74 - and as many as one-in-10 people aged 75 or over.

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Vitamin B12 (also known as cobalamin) is important as it helps to keep the nervous system healthy and helps in the production of healthy red blood cells that carry oxygen around the body.

Not having enough vitamin B12 is called vitamin B12 deficiency anaemia. Even a slight deficiency of B12 can lead to fatigue and depression, while a long term deficiency can cause irreversible damage to the brain and central nervous system.

Symptoms of B12 deficiency
A deficiency in Vitamin B12 can cause:

• unexplained fatigue
• lethargy
• yellowing of the skin
• pins and needles sensation
• a sore and red tongue
• feeling less pain
• walking problems
• headache
• feeling faint
• ringing in the ears (tinnitus)
• mouth ulcers
• muscle weakness
• vision problems
• depression
• confusion
• problems with understanding and judgement
• memory loss

When to see your GP
If you're concerned that you may have a vitamin B12 deficiency, see your GP who will be able to confirm by taking a blood test. While many of the symptoms improve with treatment, others are irreversible, so it's important to see your doctor as soon as possible.

B12 in your diet
Vitamin B12 is found naturally in animal products, including shellfish, fish, meat, poultry, eggs, milk, and milk products. Vitamin B12 is generally not present in plant foods but synthetic forms are added to many foods, such as cereals. Yeast extracts, such as Marmite, are another good source of the vitamin.

Vitamin B12 is safe to consume in large quantities as any excess is excreted by the body or stored in the liver for use when supplies are scarce. Stores of B12 can last for up to a year.

What causes vitamin B12 deficiency?
There are a number of things that can lead to a vitamin B12 deficiency. The most common cause is pernicious anaemia, an auto-immune condition that affects around one in 10,000 people. The immune system attacks healthy cells in the stomach and prevents the body from absorbing vitamin B12 from food.

Vegans and those with very restrictive diets or generally poor diets may also suffer from a lack of b12 in their diet, though this is less common.

Certain prescribed medications can also affect how much B12 your body absorbs – for example, anticonvulsants and proton pump inhibitors (PPIs) for indigestion.

Other causes include:
• atrophic gastritis, or thinning of the stomach lining
• stomach ulcers
• surgery to remove part of the stomach or small intestine
• digestive conditions such as Crohn's disease, coeliac disease, bacterial growth or a parasite

Treating vitamin B12
Your doctor can treat you with B12 supplements, which are generally given by injection. If your B12 deficiency is related to your diet, you'll need to take B12 tablets between meals. If it's caused by something else, you will most likely need to have regular injections. These treatments may be needed for the rest of your life.

Complications of vitamin B12 deficiency
Sometimes vitamin B12 deficiency can result in complications, particularly if you've been lacking in the vitamin for some time. Complications can include:

• problems with the nervous system (which can be permanent)
• temporary infertility
• heart conditions
• pregnancy complications and birth defects