Folic acid: functions, foods, deficiency and supplements

What is folic acid good for? Find out all about folic acid, including what it does, how much you need, foods rich in folic acid and who might need to supplement their diet in this guide.

Overview

Folate vs folic acid

Folic acid is the manmade version of folate – also known as vitamin B9.¹ You may see folate and folic acid used interchangeably. Don’t worry, they do the same thing!

What is folic acid used for and what does it do?

Folate / folic acid is a water-soluble vitamin used by the body to help form red blood cells, to support your immune system, and is essential for a baby’s healthy development during pregnancy.²

Folic acid is not found naturally in foods but is added to some fortified products.

Folate, however, is naturally occurring and found in a range of foods including liver, green leafy vegetables, and some beans and pulses.³

If you’re lacking in folate, you could develop a type of anaemia,⁴ while a folate deficiency in pregnancy can lead to conditions like spina bifida in unborn babies.⁵

Folic acid is available as a single supplement, or as part of a multivitamin.

Folic acid and vitamin B12

Vitamin B12 and folic acid work together in the body to perform multiple tasks, including forming red blood cells and helping nerves to function properly. They need each other.6

Function of folic acid

What does folic acid do in the body?

Folic acid benefits can be experienced throughout the body, including the following:^{7 8}

• forming red blood cells, along with vitamin B12
• contributing to a healthy immune system
• helping cells reproduce properly
• processing homocysteine, an amino acid
• helping to develop your unborn baby’s skull, brain and spinal cord develop properly

Folic acid is of enormous benefit to women during the first few weeks of pregnancy. Without it, there’s an increased risk of the baby developing neural tube defects such as spina bifida.⁹

How much folate do I need?

Your body doesn’t store folate (vitamin B9) for long periods, so it’s important to get enough from your diet.¹⁰ The reference nutrient intake for adults and children over 11 years is 200mcg a day,¹¹ roughly the same amount found in an 80g portion of edamame beans.

How much folate do over 50s need?

However, those over 50 should not consume more than 200mcg of folic acid supplements a day and keep an eye on their vitamin B12 levels:¹² too much folic acid can ‘hide’ signs of a vitamin B12 deficiency, while people over 50 are also less able to absorb vitamin B12.¹³

How much folic acid do pregnant women need?

If you’re pregnant, trying to conceive or could potentially get pregnant, it’s recommended that you take a 400mcg supplement every day until you’re 12 weeks pregnant. This is because folic acid needs to be taken before you get pregnant to ensure the health of your baby. You should pair this with 200mcg of folic acid through dietary sources, increasing to 300mcg when pregnant.¹⁴

So, if you’re thinking about stopping taking your contraception and are having unprotected sex or trying for a baby, it’s important to start taking folic acid supplements before you do so.

If you have increased risk of neural tube defect e.g. spina bifida, while you’re pregnant, have diabetes, or take epilepsy medication, a higher daily dose of 500mcg is recommended until you’re 12 months into your pregnancy.

Breastfeeding or lactating

If you are breastfeeding or lactating, it is recommended that you consume 260mcg of folic acid a day.

How much folate do children need?

Young children don’t need as much folate as adults:¹⁵

• 1–3 years old, 70mcg a day
• 4-6, 100mcg a day
• 7–10, 150mcg a day

Once they’re 11 years old, children need the same amount as adults.

What foods are high in folic acid and folate?

Lots of foods contain small amounts of folate and other household favourites get fortified with folic acid to help us get our fill.

Most people should be able to get enough folic acid through a varied and balanced diet full of wholegrains and fresh fruit and vegetables. Read below to discover some of the best foods with folic acid and folate.

What foods are the best sources of folic acid?

Folic acid, the manmade version of folate, is only found in foods that have been fortified with it. The most common foods high in folic acid include:¹⁶

Baked goods / grains

In the UK, non-wholemeal wheat flour is commonly fortified with folic acid. This means that that baked goods like the one’s listed below typically have good levels of folate – please always check the label though:

• cakes
• white bread
• biscuits
• pastries
• croissants

PS: If you prefer to eat wholegrain products e.g. wholemeal bread, it may be harder to find products that have been fortified (even though they are still very good for you!) It is recommended that you look to other food sources to meet your folic acid requirements. The same goes for gluten-free products.

Breakfast cereals

Breakfast cereals are commonly fortified with folic acid, making them a great source of this B vitamin. Check the labels to see how much folic acid they contain.

Yeast extracts

• Nutritional yeast – 5g serving contains approx. 220mcg


• Marmite – 8g serving contains approx. 210mcg

What foods are the best sources of folate?

Natural folate is available in a number of foods, including:^{15 [1]8 19 20}

Vegetables (especially leafy green ones)

• Asparagus (boiled) – 125g contains approx. 216mcg


• Wakame seaweed – 100g contains approx. 196mcg


• Dried shiitake mushrooms – 100g contains approx. 163 mcg


• Spinach (cooked) – 82g contains approx. 131mcg


• Artichokes – 100g contains approx. 119mcg


• Brussels sprouts (cooked) – 90g contains approx. 99mcg


• Kale (boiled) – 95g contains 82mcg


• White cabbage (raw) – 90g contains approx. 76mcg


• Pak choi (steamed) – 90g contains approx. 72mcg


• Rocket (raw) – 90g contains approx. 70mcg


• Broccoli (steamed) – 85g contains approx. 61mcg


• Red pepper (raw) – 90g contains approx. 60mcg


• Lettuce – 80g contains approx. 48mcg


• Beetroot (boiled) – 40g contains approx. 44mcg


• Sweetcorn (canned) – 85g contains approx. 38mcg


• Garden peas (frozen and boiled) – 80g contains approx. 25mcg

Top tip: avoid over-cooking vegetables as folate is water-soluble (dissolves easily in water) and can be lost from vegetables through cooking. Try microwaving or steaming your vegetables instead of boiling to reduce the loss.

Beans and legumes

• Edamame beans – 100g contains approx. 311mcg


• Blackeye beans – 100g contains approx. 208mcg


• Chickpeas – 100g contains approx. 172 mcg


• Pinto beans – 100g contains approx. 172 mcg


• Mung beans – 100g contains approx. 159mcg


• Black beans – 100g contains approx. 149 mcg


• Fava beans – 100g contains approx. 148 mcg


• Pea sprouts – 100g contains approx. 144mcg


• Kidney beans – 100g contains approx. 130mcg


• Lentils (red, cooked) – 120g contains approx. 40 mcg

Fruit

• Oranges – 160g contains approx. 52mcg

Orange juice can contain even more as it is often fortified (check the label)

Wholegrains

Some grains naturally have folate in small amounts, but some loaves of bread, cereal, pasta, etc. will be fortified with folic acid (see above).

• Wheat germ – 14g contains approx. 39mcg


• Quinoa – 100g contains approx. 42mcg

Meat and animal products

Popular meat products are generally low in folate, but exceptions to the rule include offal items like liver, seafood and eggs.

• Liver (not advised during pregnancy) – 100g of lamb’s liver contains approx. 400mcg


• Cooked blue mussels – 100g contains approx. 76 mcg


• Crab (Dungeness) – 80g contains approx. 36mcg


• Hardboiled egg – 1 large egg contains approx. 22mcg


• Fish (halibut, cooked) – 80g contains approx. 12mcg


• Ground beef (cooked) – 80g contains approx. 12mcg


• Chicken breast (roasted) – 80g contains approx. 3mcg

Herbs and spices

You may only use them in small amounts in cooking, but as you can see below, every little helps! Add some flavour and some folate to your dishes with herbs and spices.

• Dried basil – 10g contains approx. 31mcg


• Dried rosemary – 10g contains approx. 31mcg


• Dried coriander – 10g contains approx. 27mcg


• Ground sage – 10g contains approx. 27mcg


• Dried tarragon – 10g contains approx. 27mcg


• Dried oregano – 10g contains approx. 24mcg


• Bay leaves – 10g contains approx. 18mcg

Nuts and seeds

• Raw peanuts – 100g contains approx. 240mcg


• Dry roasted sunflower seeds – 100g contains approx. 237 mcg


• Hazelnuts – 100g contains approx. 113mcg


• Hemp seeds – 100g contains approx. 110mcg


• Toasted sesame seeds – 100g contains approx. 98mcg


• Tahini (raw sesame butter) – 100g contains approx. 98mcg


• Walnuts – 100g contains approx. 98mcg


• Flaxseed – 100g contains approx. 97 mcg

Soy products

• Firm tofu (steamed, fried)– 100g contains approx. 27 mcg


• Soy milk (fortified) – 200g contains approx. 28mcg


• Tempeh (fermented soy beans) – 100g contains approx. 76 mcg

Folate deficiency

What are the symptoms of folate deficiency?

You can get all the folate you need from your food, so a folic acid deficiency is rare. It’s usually caused by a poor or restricted diet, or by taking medication that stops your body absorbing nutrients properly.²¹ If left untreated, you could develop folate deficiency anaemia, when the body produces large red blood cells that don’t function normally. Symptoms of folate deficiency anaemia include:²²

• tiredness
• lack of energy
• weakness
• problems with memory
• sore, red tongue

Folic acid supplements

When should I take a folic acid supplement?

You’re pregnant, are trying for a baby, or could get pregnant

As mentioned above, it’s recommended that all women who are planning to get pregnant, or are in the early stages of pregnancy, take 400mcg of folic acid every day for the first 12 weeks. This should be increased to 5000mcg if you have a family history of neural tube defects, or diabetes.²⁴

You have folate deficiency anaemia

If you have folate deficiency anaemia, your GP will usually prescribe folic acid tablets you can take daily to help build up your folate levels. Most people will have to take supplements for around 4 months.²⁵ Shop Folic Acid Advice is for information only and should not replace medical care. Please talk to your GP if you’re interested in taking folic acid.

Last updated: 4 August 2020