Folate deficiency: symptoms, causes, treatment and pregnancy

The NHS says folate or B12 deficiency anaemia can cause a wide range of symptoms that usually develop gradually and can worsen if untreated. Most symptoms are the same whether caused by folate or vitamin B12 deficiency.

• Extreme tiredness, weakness and lack of energy.

• Rapid breathing or shortness of breath, and palpitations.

• Headaches, indigestion, loss of appetite and diarrhoea.

• A sore or red tongue, sometimes with mouth ulcers.

• Problems with vision.

• Pins and needles.

• Problems with memory, understanding and judgement.

• Psychological problems, from mild depression or anxiety to confusion.

Folate is vitamin B9. The NHS says vitamin B12 and folate keep the nervous system healthy and are needed for healthy red blood cells. When there is too little, the body makes unusually large, underdeveloped red blood cells that cannot carry oxygen properly, which is called megaloblastic anaemia.

Some of the problems can also happen if you have a deficiency in B12 or folate but do not have anaemia. NICE CKS notes that deficiency of vitamin B12 or folate is the most common cause of megaloblastic anaemia.

Folate dissolves in water, so the body cannot store it for long. The NHS says the store is usually enough to last 4 months, which means you need folate in your daily diet. Causes include the following.

The NHS says these conditions can often be diagnosed based on your symptoms and the results of a blood test. NICE CKS says diagnosis should be made through history, examination and investigations including a full blood count, blood film and measuring serum folate and B12 concentrations. If folate is low and the history suggests malabsorption, tests for coeliac disease should be done.

To treat folate deficiency anaemia, the NHS says a GP will usually prescribe daily folic acid tablets to build up folate levels, and may give dietary advice. Most people need to take folic acid tablets for about 4 months, but if the underlying cause continues you may have to take them for longer, possibly for life.

Before you start folic acid, the GP will check your vitamin B12 levels, because folic acid treatment can sometimes improve your symptoms so much that it masks an underlying B12 deficiency, which if untreated could affect the nervous system.

You may need a blood test around 7 to 10 days after starting treatment and another after approximately 8 weeks to confirm it has worked.

The NHS lists good sources of folate as broccoli, Brussels sprouts, asparagus, peas, chickpeas and brown rice. Improving the diet can help treat the condition and prevent it coming back, though some people also need supplements. Do not rely on diet alone if a GP has prescribed tablets.

The NHS says folic acid helps a baby’s brain, skull and spinal cord develop properly and reduces the risk of serious conditions like spina bifida. If you are pregnant you should take a folic acid supplement for the first 12 weeks, and if you are planning a pregnancy, you should start before you get pregnant, ideally 3 months before. Some women need a higher dose than others, so check with a pharmacist, midwife or doctor.

The NHS also lists pregnancy among the situations in which the body needs more folate than normal, and notes that pregnancy complications and birth defects are among the possible complications of deficiency.

The NHS says that although uncommon, B12 or folate deficiency can lead to complications, particularly if you have been deficient for some time. These include nervous system problems, temporary infertility, heart conditions, and pregnancy complications and birth defects. Adults with severe anaemia are also at risk of heart failure. Some complications improve with treatment but others, such as nervous system problems, can sometimes be permanent.

See a GP if you think you may have a vitamin B12 or folate deficiency. It is important for it to be diagnosed and treated as soon as possible because some problems can be irreversible. The GP will often check B12 as well, since the symptoms overlap.

On the NHS, a GP arranges blood tests and prescribes folic acid. If B12 deficiency or neurological symptoms are found, a haematologist may be involved. Private blood tests and vitamin clinics exist; a result outside the normal range should still be discussed with a GP, and supplements should not replace a diagnosis.