B complex vitamins are nutrients that the body needs in small amounts (micronutrients) for metabolism, energy production, and overall health of cells, skin, bones, muscles, and the nervous system. The typical way to analyze vitamins is to measure them by a chemical analytical method (usually HPLC), which, however, cannot separate the active from the inactive metabolites of the vitamins. By measuring the biologically active vitamins, their real active concentration is determined.
The B complex vitamins tested are: bioactive vitamin B1 (thiamine), bioactive vitamin B2 (riboflavin), bioactive vitamin B6 (pyridoxine), and bioactive vitamin B12 (holotranscobalamin)
What are the benefits of measuring Biologically Active Vitamins?
This test measures the biologically active in vivo metabolites of B vitamins. The biological action (bioactivity) of vitamins has a greater value and is a more representative indication of the active concentration of vitamins 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.
Measurement of biologically active vitamins is recommended when the examination of vitamins in plasma, serum, or whole blood, are in the gray zone, i.e. have borderline values and when the measured levels of vitamins are not compatible with the observed clinical picture or other laboratory tests.
The B Complex Active Vitamins Profile, measures the activity of 4 vitamins in the blood, in order to objectively evaluate the real nutritional status of a person.
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 (eg Lactobacillus fermentum, Lactobacillus rhamnosus, Lactobacillus leichmanii, Saccharomyces cerevisiae). The nutrient medium, which is 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 vitamin being examined 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.
More Information on Measured Vitamins
Vitamin B1 (thiamine)
Thiamine is passively absorbed from the intestine through diffusion and also through active transport. An enzyme converts it to thiamine pyrophosphate (TPP), the biologically active form of vitamin B1. Thiamine acts as a coenzyme in the metabolism of pentose in the liver and erythrocytes. In the nervous system, it is essential for energy metabolism and the biosynthesis of lipids and acetylcholine. Clinical symptoms of vitamin B1 deficiency include neuropathy with impaired sensitivity, burning sensation in the legs, muscle weakness, muscle spasms, loss of coordination, mood disorders and depression, fatigue, lack of concentration, memory disorders, irritability, cardiovascular disorders with tachycardia and changes in the electrocardiogram.
Vitamin B2 (riboflavin)
Vitamin B2 in its biologically active forms, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is a cofactor of many redox enzymes. Food-derived riboflavin must be released from its binding to proteins under the influence of gastric acid before it can be absorbed in the small intestine. Clinical symptoms of vitamin B2 deficiency include inflammatory disorders of the skin and mucous membranes, slow wound healing, thrombosis, atherosclerotic changes, and an increase in homocysteine.
Vitamin B6 (pyridoxal, pyridoxine, pyridoxamine)
Vitamin B6 is active as pyridoxal phosphate in many enzymatic reactions in all areas of metabolism, especially as a cofactor in amino acid metabolic reactions. Vitamin B6 is particularly important for the production of serotonin by tryptophan and as a cofactor of the histamine breakdown enzyme, diaminoxidase (DAO). Clinical symptoms of vitamin B6 deficiency are neurological disorders (ataxia, paralysis), insomnia, irritability, sensitivity disorders, inflammation of the skin and mucous membranes, neuritis, changes in blood tests (cytopenia, anemia), histamine intolerance, disturbance of intestinal absorption of trace elements and increased homocysteine.
Serum vitamin B12 is bound to two protein carriers. About 70-90% of vitamin B12 is bound to Haptocorrin (HC, also called Transcobalamine 1) and this form is metabolically inactive. The remaining 10-30% of B12 is bound to Transcobalamin 2 (TC2) and this is the bioavailable, active fraction, as it can bind to receptors on cell membranes and then be received by these cells. The Transcobalamin 2-Vitamin B12 complex is called Holotranscobalamin or Active B12.
The standard chemical measurement of vitamin B12 measures total B12, ie both the HC-B12 complex (inactive fraction) and the active B12. This sometimes leads to diagnostic problems. A typical example is low B12 levels which do not correspond to the observed clinical picture. Clinical studies show that 15-40% of patients with low B12 do not actually have B12 deficiency.