Folic Acid

Description Folic Acid, known as folate in its natural form, is a synthetic water-soluble vitamin and is part of the B-vitamins group. Folic acid is generally consumed in the form of food supplements or in fortified foods.
Function/ Used for Essential during pregnancy for efficient neural tube development which forms the brain and spinal cord. ‘Neural tube defects’, such as spina bifida, in babies appear to be linked to a ‘metabolic defect’ in folate metabolism in the mother. This means that, even though the mother may have an adequate dietary intake of folic acid, her body cannot use it efficiently. Taking extra folic acid at the time when the neural tube is forming can reduce the chance of the baby having a neural tube defect. However, the neural tube is formed very early during pregnancy – about a month after conception. Women are advised to take folic acid for 12 weeks prior to conception and to continue taking folic acid supplements until the 12th week of pregnancy.


In addition, folic acid is essential for the formation of red blood cells and has been shown to reduce the levels of an amino acid (homocysteine). This reduction may have a protective effect against heart disease.1

Folic Acid also contributes to brain health, immune function as well as helping to reduce tiredness and fatigue.

Intake Recommended Intake

EU NRV: 200µg


Women of childbearing age (14-49 years) who are planning or who may become pregnant are advised to take a supplement containing 400µg folic acid every day.


UK average daily intake

Requirements vary depending on age and gender. The UK National Diet and Nutrition Survey lists up-to-date intake requirements and average intakes2.

As a supplement Available as a single supplement. Also commonly available as part of a multivitamin and mineral formula.

Different multivitamin and minerals products will vary in the percentage NRVs they include. People should always check the label for information about a specific product.

Found in (dietary sources) ‘Folate’ can be found naturally in yeast extract, wholegrain cereals, liver, brussels sprouts, broccoli, leafy green vegetables, beans, oranges and beer.

Levels of folate are unstable, unless the foods are refrigerated, and can also be destroyed by processing and cooking.

‘Folic acid’ can be sourced from fortified foods, such as breakfast cereals, marmite, bovril and fat spreads.

Deficiency Folate deficiency may lead to an increased risk of neural tube defect (spina bifida) in babies.

Folate deficiency may cause macrocytic megaloblastic anaemia (enlarged but fewer red blood cells).5

Precautions and contraindications Safe Upper Level: 1000µg/day3
Use in pregnancy and breastfeeding No problems have been reported. Supplements are required during pregnancy and when planning a pregnancy.
Interactions e.g. with other medications Those taking anti-epileptic drugs should seek doctor’s advice. Prolonged use of oral contraceptives may cause folic acid depletion4.

Adequate amounts of all B vitamins are required for optimal functioning. Deficiency or excess of one B vitamin may lead to abnormalities in the metabolism of another. Folic acid may reduce the absorption of zinc.

Adverse effects Folic acid is generally considered to be safe even in high doses, but it may lead to convulsions in patients taking anticonvulsants and  to neuropathy in patients with pernicious anaemia.5


Some gastrointestinal disturbance has been reported at doses of 15 mg daily. Allergic reactions (shortness of breath, wheezing, fever, erythema, skin rash, itching) have been reported rarely.5

References 1.       NHS Choices.


3.       Expert Group on Vitamins and Minerals, 2003.

4.       Gaby, A. R. A-Z Guide to Drug-Herb-Vitamin Interactions. HealthNotes 2006.

5.       Mason, P. Dietary Supplements. Pharmaceutical Press, London, 2001. 4.