Biologically active vitamin Β9 (folic acid) is a test based on a microbiological method that measures the total vitamin Β9 content in a blood sample.
What are the benefits of measuring Biologically Active Vitamins?
This test measures the biologically active in vivo metabolites of B vitamins. Vitamins' biological action (bioactivity) has more excellent value. It is a more representative indication of their active concentration than the simple chemical measurement of their levels, especially in cases where these indications are used to determine substitution therapy or to check a therapeutic intervention.
Folic acid (vitamin B9) belongs to the group of the vitamin B complex; it is water soluble, sensitive to light, oxygen, and increased temperatures, and is essentially involved in all body growth and development processes. Folic acid is necessary to form red blood cells, for optimal bone marrow function and healthy nerve activity. Folic acid is also essential for all cell divisions (hence its importance in fetal development). Although folic acid is found in most plant and animal foods, an undersupply of folic acid is the most common vitamin deficiency in Europe and North America. According to studies, only one in four north-Europeans consumes enough folic acid, often resulting from an unbalanced diet with little fresh fruit and vegetables. However, age, various diseases, and the intake of certain medicines, such as cotrimoxazole, can also lead to absorption disorders and an associated deficiency.
Lowered folic acid levels occur because of:
- Decreased supply (e.g., folic acid antagonists).
- Disrupted resorption (e.g., in celiac disease and chronic diarrhea).
- Increased requirement (e.g., increased alcohol consumption. when taking contraceptives. during pregnancy. anemia, or cancer).
Symptoms of Deficiency
The early symptoms of deficiency are fatigue, irritability, depression, poor concentration, and loss of appetite; other consequences are inflammation of the mucous membranes, anemia, and severe neurological damage. During pregnancy, when the need for folic acid doubles, a deficiency can lead to premature birth and severe malformations. Optimal folic acid supply during pregnancy can reduce the risk of neural tube defects in the fetus by 85%. Since both a folic acid and a vitamin B12 deficiency can cause megaloblastic anemia, determining both vitamins is particularly important in this clinical picture to supplement the proper vitamin. Treatment of megaloblastic anemia caused by vitamin B12 deficiency with folic acid alone can lead to irreversible damage to the central nervous system.
Folic acid and arteriosclerosis
A folic acid deficiency is known to be the most common cause of hyperhomocysteinemia. Hyperhomocysteinaemia has been recognized as an independent factor in arteriosclerosis. Therefore, folic acid can be determined within a coronary disease risk analysis framework. Apart from the influence of folic acid on the homocysteine levels, a further positive effect on the endothelial function in heart patients has been established – the development of nitrate tolerance during continuous nitrate therapy, e.g., in such patients, an increased release of oxygen radicals occurs without folic acid supplementation.
Indications of biologically active vitamin Β9 measurement
- Macrocytic anemia
- Long-term therapy with antiepileptic drugs or folic acid antagonists
- Long-term hemodialysis
- Multiple pregnancy / planned pregnancy
- Enhanced erythropoiesis
- Chronic liver diseases
- Psoriasis, dermatitis
- Stomatitis, glossitis
- Chronic alcohol abuse
How are Biologically Active Vitamins measured?
To test the biologically active vitamins, the blood sample is subjected to an enzymatic pre-treatment and then placed in microplates containing microorganisms sensitive to these vitamins (e.g., Lactobacillus fermentum, Lactobacillus rhamnosus, Lactobacillus leichmanii, Saccharomyces cerevisiae). The nutrient medium, specific and unique to each vitamin, contains all the necessary ingredients for the growth of microorganisms, except for the vitamin to be measured. When the patient's blood is added to the material, the microorganisms grow until the examined vitamin is depleted. The growth of microorganisms is measured after 72 hours of incubation in a special multi-channel analyzer and compared to standard concentrations of vitamins. The bioactivity of the tested vitamin is directly proportional to the measured growth of microorganisms.
