Analysis index

1 ml serum (Stability in serum at 4°C – 8°C: 2 days)

Disruptive elements: Hemolysis, eating within the last 12 hours before blood extraction, it is therefore required to take bloods in an empty-stomached patient. A potential methotrexate treatment should be discontinued 1 week prior to blood extraction.

3,1 µg/l – 20,5 µg/l

Decreased folic acid supply in pregnant women, alcohol addicts, drug addicts, in case of insufficient intake of fresh fruit and vegetables as well as in people with structural or functional small intestinal disorders. It is indicated to test  patients with confirmed megaloblastic anemia as well as in all patients with anemia, hypersegmentation of granulocytes, liver damage and iron deficiency, malabsorption, hyperhomocysteinemia, in case of tropic and gluten-sensitive sprue as well as in case of treatment with folic acid antagonists such as methotrexate.

Folic acid (Pteroylglutamic acid, vitamin B9 or vitamin M) is found in vegetable- and animal-based food products; in addition, there is a synthesis in the intestinal flora. Despite this, folic acid deficiency is the most common vitamin deficiency. Apart from malnutrition and malabsorption, various medication such as anticonvulsants or folic acid antagonists can induce a deficiency, whereby folic acid antagonists mainly disturb the transformation into biologically active tetrahydrofolic acid (THF), whilst the folate level in the serum can still show normal values due to measuring inactive metabolites in the immunoassay. Folic acid is transformed intracellular into different metabolic active derivates such as THF, methyltetrahydrofolic acid (MTHF) or 5-formyl-THF. In the form of methyl- or formyl group donors, these play an integral part in the nuclein bases synthesis or methylation reaction, the latter via MTHF- and vitamin B12-induced transformation from homocysteine to methionine, which is the actual methyl group donor for proteins such as myelin, nucleic acids or neuro transmitters. Due to the joint effect of vitamin B12 and folic acid in biosynthesis of nuclein bases or methylation reaction, folic acid deficiency presents clinically identical to vitamin B12-deficiency with hyperchromic-macrocytic anemia and neurological symptoms. In addition to this, there is hyperhomocysteinemia, however no methylmalonic acidemia. Due to this, the additional evaluation of vitamin B12 is required for differential diagnostic reasons. Due to the markedly shorter storage capacity compared to vitamin B12, folate deficiency already shows after 4 – 5 months.

More recent studies show, that in 80 % of women between the age of 18 to 40, folic acid supply is suboptimal. Increased requirements during pregnancy, infections or growth periods. An insufficient folic acid supply in early pregnancy is jointly responsible for neural tube defects. Folic acid requirements during pregnancy are hardly met by normal eating habits. Accordingly, expert panels recommend the daily use 0,4 mg folic acid in addition to normal food to women, who don’t actively prevent conception or who desire to have a baby.