The treatment for vitamin B12 or folate deficiency anaemia depends on what's causing the condition. Most people can be easily treated with injections or tablets to replace the missing vitamins.
Vitamin B12 deficiency anaemia is usually treated with injections of vitamin B12, called hydroxocobalamin.
At first, you'll have these injections every other day for 2 weeks or until your symptoms have started improving.
Your GP or nurse will give the injections.
After this initial period, your treatment will depend on whether the cause of your vitamin B12 deficiency is related to your diet or whether the deficiency is causing any neurological problems, such as problems with thinking, memory and behaviour.
The most common cause of vitamin B12 deficiency in the UK is pernicious anaemia, which is not related to your diet.
If your vitamin B12 deficiency is caused by a lack of the vitamin in your diet, you may be advised to take vitamin B12 tablets every day between meals.
Or you may need to have an injection of hydroxocobalamin twice a year.
People who find it difficult to get enough vitamin B12 in their diets, such as those following a vegan diet, may need vitamin B12 tablets for life.
Although it's less common, people with vitamin B12 deficiency caused by a prolonged poor diet may be advised to stop taking the tablets once their vitamin B12 levels have returned to normal and their diet has improved.
Good sources of vitamin B12 include:
If you're a vegetarian or vegan, or are looking for alternatives to meat and dairy products, there are foods that are fortified with vitamin B12, such as some yeast extracts, breakfast cereals and soy products.
Check the nutrition labels while food shopping to see how much vitamin B12 different foods contain.
If your vitamin B12 deficiency is not caused by a lack of vitamin B12 in your diet, you'll usually need to have an injection of hydroxocobalamin every 2 to 3 months for the rest of your life.
If you have had neurological symptoms that affect your nervous system, such as numbness or tingling in your hands and feet, caused by a vitamin B12 deficiency, you'll be referred to a haematologist and may need to have injections every 2 months.
Your haematologist will advise on how long you need to keep taking the injections.
For injections of vitamin B12 given in the UK, hydroxocobalamin is preferred to an alternative called cyanocobalamin. This is because hydroxocobalamin stays in the body for longer.
To treat folate deficiency anaemia, your GP will usually prescribe daily folic acid tablets to build up your folate levels.
They may also give you dietary advice so you can increase your folate intake.
Good sources of folate include:
Most people need to take folic acid tablets for about 4 months. But if the underlying cause of your folate deficiency anaemia continues, you may have to take folic acid tablets for longer, possibly for life.
Before you start taking folic acid, your GP will check your vitamin B12 levels to make sure they're normal.
This is because folic acid treatment can sometimes improve your symptoms so much that it masks an underlying vitamin B12 deficiency.
If a vitamin B12 deficiency is not detected and treated, it could affect your nervous system.
To ensure your treatment is working, you may need to have further blood tests.
A blood test is often carried out around 7 to 10 days after starting treatment to assess whether treatment is working.
This is to check your haemoglobin level and the number of the immature red blood cells (reticulocytes) in your blood.
Another blood test may also be carried out after approximately 8 weeks to confirm your treatment has been successful.
Most people who have had a vitamin B12 or folate deficiency will not need further monitoring unless their symptoms return or their treatment is ineffective.