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Folic acid (folate, folacin, vitamin B9)

Folic acid (folate, folacin, vitamin B9)The most common term for this nutrient is folic acid, whereas vitamin B9 is hardly ever used. Folic acid is the synthetic form that is found in vitamin pills, while folate and folacin are the forms of the nutrient that are found naturally in food. Folic acid is very stable and gets converted into folate in the body. The vitamin is water-soluble. Most of it gets stored in the liver, which contains around half the body's total amount of folate. The nutrient is destroyed by boiling and heating.

Functions and importance for

  • Cell division in the body
  • Energy levels
  • Fertility (male and female)
  • Tissue growth and development during pregnancy
  • Synthesis of amino acids - the building blocks of protein
  • Formation of red blood cells (that carry oxygen to all the tissues in the body)
  • Blood levels of the amino acid homocysteine
  • Mental balance
  • The immune system
  • Reduction of fatigue and exhaustion

Planning of pregnancy

Folic acid reduces the risk of giving birth to a child with a neural tube defect. The neural tube of the fetus normally closes about a month after the time of conception and then continues developing into the brain and spinal cord. If the neural tube fails to close it may cause a deformity that prevents the brain from developing normally and may lead to stillbirth. Lack of folic acid may also cause heart defects and neural tube defect which can result in severe disabilities, including leg paralysis. Although these problems are relatively rare, it is advisable to take supplements of folic acid right from the time where the pregnancy is planned.

Deficiencies and poor utilisation may be caused by

  • Overconsumption of alcohol
  • Narcotics and medicine abuse
  • Pregnancy
  • Smoking
  • Poor intestinal flora
  • Unbalanced diets and inferior dieting strategies
  • Old age (especially in combination with an unbalanced diet)
  • Contraceptive pills
  • Cholesterol-lowering drugs (cholestyramine and Colestipol)
  • Epilepsy drugs (Phenytoin)
  • Methotrexate against rheumatism and cancer

Deficiency symptoms

  • Fetal damage (neural tube defects, heart defects)
  • Anemia (megaloblastic anemia), the same type as seen with vitamin B12 deficiencies. The symptoms occur because the cells lack oxygen. This may cause fatigue, heart palpitations, shortness of breath, dizziness, and in severe cases headache, heart cramp, and leg pain (intermittent claudication)
  • Impaired mental and physical development in the childhood (even though anemia does not occur)
  • Tongue infection with discolouring of the oral mucosa (glossitis)
  • Impaired sense of taste
  • Indigestion and intestinal gas
  • Diarrhea
  • Myelopathy (muscle disease)
  • Depression
  • Lack of folic acid is often accompanied by a vitamin B12 deficiency

Blood samples and diagnosis

Anemia and folic acid deficiency are detectable by means of a blood sample. An elevated level of the amino acid homocysteine in the blood also lends support to the diagnosis.


Mainly liver, legumes, kale, asparagus, sprouts, nuts, eggs, vegetables, fruit, and dairy products.

Content of folate (vitamin B9) in micrograms per 100 grams

Beef liver 2,300
Broccoli 239
Cholestyramine 140


Cheese 60

Recommended daily allowance (RDA)

Adults: 11 years of age and older: 200 micrograms
Children: 1-10 years of age: 75 micrograms
Pregnancy: 400 micrograms daily. It is important to continue supplementing at least 12 weeks into the pregnancy to reduce the risk of giving birth to a child with a neural tube defect. In addition, it is recommended to start supplementing from the moment the pregnancy is planned.

Increased need

  • The mentioned deficiency symptoms and with the use of medical drugs
  • In situations with a large number of cell divisions such as during pregnancy and child growth
  • Smoking
  • Dialysis (causes depletion of the nutrient)
  • Poor intestinal flora, celiac disease, and impaired nutrient absorption

Important information

Supplements should normally be taken with other B vitamins and not together with antacids.

Overdosing - side effects

Very rarely seen, as the vitamin is water-soluble and is excreted with the urine.


Supplements of folic acid should not be taken together with cholesterol-lowering drugs that work by binding bile.