Folic acid (vitamin B9)

Folic acid or vitamin B9 is an active ingredient and a vitamin from the B group. It is water-soluble and a central building block in DNA and RNA synthesis. Vitamin B9 is very important during pregnancy as it prevents neural tube defects and deficiencies. Folic acid can also be used as a treatment for megaloblastic anemia. It is usually available as a yellowish or orange-colored crystalline powder and is a prodrug. A prodrug is an inactive substance that only becomes active in the body and only after conversion. Folic acid or vitamin B9 is found in various foods such as wholemeal products, green leafy vegetables, spinach, carrots and many more. It is sensitive to light, heat and oxygen and should therefore not be cooked for too long.

Folic acid has a protective effect on cardiovascular diseases and cancer. The daily requirement for adults and children aged 13 and over is 0.3-0.4 mg per day. It should be noted that women who are pregnant or breastfeeding have a higher requirement. This is between 0.4 mg and 0.6 mg daily. In blood findings, a folic acid concentration of >2.5 ng/ml in serum/plasma is considered normal, below this level it is considered deficient. German pediatricians are calling for the mandatory addition of folic acid to flour in order to reduce neural tube defects. This has already been practiced in the USA and Canada for many years. Vitamin deficiencies and the number of children born with neural tube defects are declining significantly. However, German consumer advocates are critical of this.

Vitamin B9 is responsible for or involved in several mechanisms in the body. As a central building block, however, it is required in DNA and RNA synthesis, above all in the synthesis of purines, pyrimidines and the amino acid methionine. Folic acid is also needed in the body in processes where a lot of cell division takes place, which explains its necessity during pregnancy and childhood. It is also needed for blood formation.

Vitamin B9 is converted in the liver and excreted in the urine. The maximum plasma concentration (Cmax), i.e. the maximum concentration of the active ingredient in the blood plasma (liquid cell-free part of the blood), is reached after about one hour. The metabolites (products from the conversion of folic acid) of folic acid can cross both the blood-brain barrier and the blood-cerebrospinal fluid barrier.

Always take folic acid exactly as described in the package leaflet or as advised by your doctor.

The usual recommended dose for megaloblastic anemia is 1 mg daily.

The recommended maintenance dose is 0.4 mg daily and 0.8 mg daily during pregnancy and breastfeeding .

The recommended intake for the treatment of folic acid deficiency or for vitamin supplementation is 0.4 mg per day. Up to 0.5 mg should be taken daily during breastfeeding and up to 0.6 mg during pregnancy .

The following side effects may occur:

• allergic reactions of the skin
• shortness of breath
• nausea
• gastrointestinal complaints
• sleep disturbances
• agitation
• depression
• Mucosal damage
• diarrhea

Interactions may occur if the following medicines are taken at the same time:

• Medication for the treatment of epilepsy (anticonvulsants)
• Trimethoprim
• proguanil
• pyrimethamine
• methotrexate
• 5-Fluorouracil
• chloramphenicol

Folic acid/vitamin B9 must NOT be taken in the following cases

• in case of allergy to folic acid
• in case of megaloblastic anemia due to a vitamin B12 deficiency

Folic acid can be used from birth.

Folic acid should be used during pregnancy to prevent neural tube defects and primitive neuroectodermal tumors in the unborn child. A dosage of 0.4 mg daily is usually recommended in the first trimester of pregnancy. If you wish to have children, you can also start taking 0.4 mg folic acid daily 4 weeks before pregnancy.

Folic acid can also be taken prophylactically during breastfeeding in order to cover the higher requirement during the breastfeeding period.

Folic acid was first discovered in 1941 and was first isolated from spinach leaves. The name comes from the Latin term "folium", which means "leaf".