Folate vs folic acid – what’s the difference?

Discover the role of folate, the symptoms of folate deficiency, and how to boost your folic acid intake.

Folate is an essential B vitamin that is crucial for keeping in good health. You may have heard about folic acid supplements for early pregnancy, where they’re important for preventing spinal tube defects in the developing baby.  

However, a folate deficiency in adults can also cause problems. It can lead to a variety of symptoms, and even anaemia if it’s not treated.

In this article, we cover:  


What is folate?

Folate is the naturally occurring form of vitamin B9. It’s found mainly in leafy vegetables, seeds, nuts, grains, and beans.  


Why is folate important? 

All B vitamins help the body convert food to energy. As well as this, folate has other important roles in the body.  

Folate is important for:  

  • Making red and white blood cells   
  • Regulating homocysteine levels (an amino acid used to make protein) – excessive levels of homocysteine can increase your risk of stroke, certain types of heart disease, and disease of the blood vessels in the arms, legs, and feet.   
  • DNA replication and protection – folate is required for all cell division and growth in the body, such as in sperm production, red blood cell production, and nail and hair growth.   
  • Pre-conception and pregnancy – folate is important to prevent the baby from developing neural tube defects, like spina bifida. 


Folate vs folic acid – what’s the difference? 

Whereas folate occurs naturally in foods, folic acid is a synthetic form of vitamin B9.  

Folic acid is sometimes used to fortify foods such as flour and breakfast cereals. It can also be taken as a supplement for people who are deficient in folate or for pregnant women.   

Unlike folate, not all folic acid is converted into the active form of vitamin B9 in the digestive system. Therefore, it’s best to get folate from your diet if you can.  


Why do I need a serum folate blood test? 

A folate blood test is usually used to diagnose and monitor folate deficiency.  

Your doctor may request a folate test if you:  

  • Have symptoms of folate deficiency 
  • Are at risk of malnutrition 
  • Have a condition that affects absorption (such as inflammatory bowel disease)  
  • Drink alcohol in excess for long periods of time 
  • Have unexplained anaemia 
  • Are known to have folate deficiency and need monitoring 


What is a normal folate level?  

Reference ranges for folate vary significantly between labs. A normal folate level is approximately 4–20 μg/L or 9–45 nmol/L for adults.  

Confusingly, labs sometimes use different units to measure folate. The table below shows how folate levels may be interpreted.  

Probable folate deficiency < 3 μg/L < 7 nmol/L
Possible folate deficiency 3–4.5 μg/L 7–10 nmol/L
Normal folate level 4–20 μg/L 9–45 nmol/L
Raised folate level > 20 μg/L > 45 nmol/L

There is a grey zone where folate deficiency is possible, but not confirmed. If you fall into this category but don’t have symptoms and you’re not at risk of folate deficiency, this is not usually of concern.   


Folate deficiency symptoms

Low folate can lead to a deficiency in just a matter of weeks.  

Symptoms of low folate include:  

  • Lack of energy 
  • Muscle weakness 
  • Low mood 
  • Tender, red tongue 
  • Mouth ulcers 
  • Reduced sense of taste 
  • Memory loss 
  • Difficulty concentrating 
  • Nerve problems, such as pins and needles or numbness 

Over time, low folate levels can affect the production of red blood cells and lead to folate deficiency anaemia. Anaemia is a condition in which there are too few red blood cells, which normally carry oxygen to the tissues.  

Symptoms of folate deficiency anaemia include:  

  • Fatigue 
  • Pale skin 
  • Shortness of breath 
  • Dizziness 


What causes folate deficiency? 

Folate is an essential vitamin, which means you need a constant supply of folate in your diet as your body can’t make it. As it’s water-soluble, the body can’t store it in your fat cells either.  

The last National Diet and Nutrition Survey 2016–2019 [1] showed that folate levels have been falling over time. Folate levels in women of childbearing age have dropped by more than 25% in the last decade, which can increase the risk of neural tube defects in babies, such as spina bifida. 

Folate deficiency is usually due to reduced intake, poor absorption, or medication side effects.  

Causes of folate deficiency include:  

  • Poor diet – Even though a diet low in fresh fruits and vegetables is one of the main causes of folate deficiency. Although some ultra-processed foods are fortified, relying on them means missing out on the naturally occurring folate present in whole foods. Studies have found that people who ate lots of ultra-processed foods also had the lowest folate intake [2].  
  • Alcohol – People who regularly drink lots of alcohol don’t absorb nutrients as well, especially B vitamins.
  • Digestive diseases – Conditions like Crohn’s and coeliac disease affect how well the gut absorbs folate.
  • Medications – Medications like phenytoin, trimethoprim, sulfasalazine, and methotrexate can affect the conversion of folate into its active form.
  • Excessive urination – Conditions like heart failure may cause you to lose more folate than normal 
  • Genetics – A rare condition called hereditary folate malabsorption (HFM) causes low folate.

There are occasions when the body’s demand for folate increases. 

You may need more folate than usual if you:  

  • Are pregnant 
  • Have cancer 
  • Have a blood disorder, like sickle cell anaemia 


What are the complications of a folate deficiency?  

Folate deficiency, with or without anaemia, has been associated with certain complications and conditions.  


Having low folate can affect your chances of getting pregnant. The good news is that this can usually be reversed with folic acid supplements [3]. 

Problems in pregnancy 

As well as making it more difficult to get pregnant, low folate can affect the developing baby. Low folate during pregnancy is associated with neural tube defects, such as spina bifida. It can also increase the risk of premature delivery, placental abruption, and low birth weight [3]. 

Folate levels have been falling in women of childbearing age over time. In the UK, over one in 1000 births is affected by neural tube defects [4].  

Cardiovascular disease 

Research shows that low (or very high) folate levels may increase your risk of heart disease mortality by increasing homocysteine levels [5]. Homocysteine is an amino acid. If levels are persistently raised, it can make you more prone to heart attacks and stroke. 


How can I check for a folate deficiency? 

You can check your folate levels at home with our Folate Blood Test

If you have folate deficiency anaemia, the NHS recommends checking vitamin B12 levels before starting folic acid supplements [6]. You can check your folate and B12 levels together with our Vitamin B12, Folate, and Ferritin Blood Test


How much folate do I need? 

Adults need 200 μg of folate a day. Most people get the folate they need from a nutritious and varied diet.  

If you’re trying for a baby or could get pregnant, you need more than this. It’s recommended that you take a 400 μg supplement until you’re 12 weeks pregnant. 

Some women may benefit from a higher dose of folic acid (5 mg) if they are at great risk of having a baby with neural tube defects.  

Women may need to take high-dose folic acid before and during the first trimester if they:  

  • Have diabetes, sickle cell anaemia, or thalassaemia 
  • Are obese 
  • Have a malabsorption disorder 
  • Have had a previous pregnancy with neural tube defects 
  • Take anti-epilepsy medication 


How can I increase my folate levels? 

You can increase your folate levels by ensuring your diet is rich in fruit and vegetables, and folate-fortified foods. 

Foods rich in folate include: 

  • Edamame beans – 121% DV per cup 
  • Lentils – 90% DV per cup, cooked 
  • Chickpeas – 71% DV per cup, cooked 
  • Asparagus – 67% DV per cup, cooked 
  • Spinach – 66% DV per cup cooked 
  • Kidney beans – 58% DV per cup, cooked 
  • Marmite – 50% DV per 8g serving 
  • Broccoli – 42% DV per cup cooked  
  • Avocado – 41% DV per avocado 
  • Kale – 21% DV per cup, cooked 

As well as naturally occurring sources of folate, some foods have folate added to them. For example, following a 2019 consultation, the government announced the addition of folic acid to all UK-milled wheat flour. 

Exampled of folate-fortified foods include: 

  • Enriched bread (e.g. rolls, bagels, and buns) 
  • Enriched pasta (e.g. spaghetti) 
  • Enriched white rice (brown rice isn’t usually fortified with folic acid) 
  • Fortified breakfast cereals (e.g. Weetabix, Special K, Cheerios, Rice Krispies, All-Bran, Bran Flakes) 

While wholemeal and wholegrain foods aren’t fortified, they’re often preferable as they have many other nutritional benefits. There has been a call for more foods, like wholemeal flours, to be fortified with folate[7]. Beware that some cereals contain lots of sugar and other additives. 

Even with a healthy diet, some people don’t get enough folate. In these cases, a folic acid supplement may be helpful.  


Who should take a folic acid supplement? 

For most people, it’s best to get folate from food. However, certain individuals benefit from taking a folic acid supplement.  

If you’re pregnant or could get pregnant 

If you’re trying for a baby or could get pregnant, it’s recommended you take a 400 μg supplement until you’re 12 weeks pregnant. 

Folic acid supplements should be taken before you get pregnant (ideally a few months before), so start taking them before you stop using contraception.  

Folic acid can help prevent neural tube defects, such as spina bifida, affecting your baby.  

Some women have an increased risk of having a baby with a neural tube defect and are advised to take a higher dose of 5mg.  

If you have a folate deficiency 

Some people have folate deficiency due to a condition that affects folate absorption, such as Crohn’s disease. In these cases, a folic acid supplement can help to increase your folate levels. 

Before starting a folate supplement 

Before starting a supplement, it’s important to check your vitamin B12 levels first to make sure they’re normal. If you have vitamin B12 deficiency and take folic acid supplements, it can mask the symptoms of low vitamin B12 and lead to a delay in diagnosis.   


Is folic acid 5mg prescription only? 

High-dose folic acid supplements can only be prescribed by your doctor. See your doctor if you think you need a higher dose.  

Lower doses of folic acid, such as 200–400μg, can be bought over the counter.  


What happens if I take too much folic acid? 

Taking less than 1mg of folic acid a day isn’t thought to cause harm. Doses higher than this are more likely to cause side effects. 

Taking too much folic acid may cause: 

  • Stomach upset 
  • Nausea 
  • Diarrhoea 
  • Irritability 

If you have been prescribed a higher dose of folic acid and experience side effects, speak to your doctor first before stopping the tablets. 


How and when to take folic acid 

You can take folic acid with or without food. Swallow the tablets whole with a drink of water. It doesn’t matter what time of day you take folic acid.  


Getting enough folate 

Folate is essential for maintaining optimal health. Thankfully, most of us can keep our levels topped up with a diverse diet rich in leafy greens, legumes, and fortified foods.  

If you’re worried your folate levels might be low, it’s important to see your GP. You can also check your levels from home yourself with one of our Folate Blood Tests.  



  1. NDNS: results from years 9 to 11 (2016 to 2017 and 2018 to 2019). In: GOV.UK [Internet]. [cited 12 Sep 2023].
  2. Wang L, Martínez Steele E, Du M, Pomeranz JL, O’Connor LE, Herrick KA, et al. Trends in Consumption of Ultraprocessed Foods Among US Youths Aged 2-19 Years, 1999-2018. JAMA. 2021;326: 519–530.
  3. Vitamin B12 or folate deficiency anaemia - Complications. NHS. 20 Oct 2017 [cited 1 Sep 2023].
  4. Peake JN, Knowles RL, Shawe J, Rankin J, Copp AJ. Maternal ethnicity and the prevalence of British pregnancies affected by neural tube defects. Birth Defects Res. 2021;113: 968–980. doi:10.1002/bdr2.1893
  5. Otsu Y, Ae R, Kuwabara M. Folate and cardiovascular disease. Hypertens Res. 2023;46: 1816–1818. doi:10.1038/s41440-023-01307-w
  6. Scenario: Management | Management | Anaemia - B12 and folate deficiency | CKS | NICE. [cited 1 Sep 2023].
  7. UCL. Government urged to set the right level of folic acid in flour to prevent severe birth defects. In: UCL News [Internet]. 22 Aug 2022 [cited 12 Sep 2023].