Description
Thiamine, or thiamin, sometimes called aneurin, is a water-soluble vitamin of the B complex (vitamin B1), whose phosphate derivatives are involved in many cellular processes. The best characterized form is thiamine diphosphate (ThDP), a coenzyme in the catabolism of sugars and amino acids.
Animals must cover all their needs from their food and insufficient intake results in a disease called beriberi affecting the peripheral nervous system (polyneuritis) and/or the cardiovascular system, with fatal outcome if not cured by thiamine administration. In less severe deficiency, nonspecific signs include malaise, weight loss, irritability and confusion.
Majority of thiamine in serum is bound to proteins, mainly albumin. Approximately 90% of total thiamine in blood is in erythrocytes. A specific binding protein called thiamine-binding protein (TBP) has been identified in rat serum and is believed to be a hormonally regulated carrier protein that is important for tissue distribution of thiamine.
Concentration of vitamin B1 is measured by means of analysis of a blood sample drawn from the vein in the arm.
Purpose of the test
The purpose of this test is to meassure the concentration of Vitamin B1 by means of analisys of a blood sample.
Thiamine derivatives and thiamine-dependent enzymes are present in all cells of the body, thus, a thiamine deficiency would seem to adversely affect all of the organ systems. However, the nervous system and the heart are particularly sensitive to thiamine deficiency, because of their high oxydative metabolism.
Total thiamine, measured as thiamine (vitamin B1) and thiamine monophosphate, is reported. However, the biologically active form of the vitamin, thiamine diphosphate (TDP), is best measured in whole blood, and is not found in measurable concentration in plasma. Plasma thiamine concentration reflects recent intake rather than body stores.
Whole blood is the preferred specimen for thiamine assessment. Approximately 80% of thiamine present in whole blood is found in red blood cells.
Reference range values
8-30 nmol/L
Abnormal findings
Thiamine deficiency can lead to myriad problems including neurodegeneration, wasting and death. A lack of thiamine can be caused by malnutrition, a diet high in thiaminase-rich foods (raw freshwater fish, raw shellfish, ferns) and/or foods high in anti-thiamine factors (tea, coffee, betel nuts) and by grossly impaired nutritional status associated with chronic diseases, such as alcoholism, gastrointestinal diseases, HIV-AIDS, and persistent vomiting. It is thought that many people with diabetes have a deficiency of thiamine and that this may be linked to some of the complications that can occur.
Well-known syndromes caused by thiamine deficiency include beriberi and Wernicke-Korsakoff syndrome, diseases also common with chronic alcoholism.