Vitamin B12 And Folic Acid | Dr. Schweikart
RBC folate, Serum vitamin B, Dietary of the test without additional laboratory assessment. . the relation of vitamin B to methylmalonic acid. Laboratory tests for folate and vitamin B12 are essential for the diagnosis of of serum and red cell folate levels in relation to body folate stores. Overview of vitamin B12 and folate deficiencies and tests used to diagnose and monitor these conditions.
You may also have this test if you have a disease or condition that could lead to B deficiency. Symptoms of B deficiency include: Fatigue Numbness or "pins and needles" in the hands and feet Difficulty walking Difficulty thinking normally Changes in mood Symptoms of having too little folate are diarrhea, weight loss, and other vague symptoms that could be caused by many other conditions.
It's important that women who are pregnant, thinking of becoming pregnant, or breastfeeding have enough folate. This test measures both vitamin B and folate, but either of these nutrients can be measured separately in different lab tests.
Your healthcare provider may order this combined test if you have a condition for which it's important to know both levels. What other tests might I have along with this test? Your healthcare provider may also order these tests: Homocysteine and methylmalonate, or methylmalonic acid. These substances can build up in your body if you have a B or folate deficiency.Methyl Trap of Homocysteine Cycle - Folate and B12
Red blood cell Pernicious anemia. This includes measuring levels of gastrin, pepsinogen I, pepsinogen II, and antibodies against a substance called intrinsic factor. What do my test results mean? Test results may vary depending on your age, gender, health history, the method used for the test, and other things.
Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. If your B results are low, it may mean you have: Pernicious anemia Stomach issues, such as lack of stomach acid, that make it difficult to absorb the vitamin Folate deficiency Your diet can also lead to B deficiency.
Vitamin B and Folate - Health Encyclopedia - University of Rochester Medical Center
Preferred biochemical nomenclature for vitamin B is cobalamin, which is the generic term for the group of cobamide vitamers that all possess the base 5,6-dimethylbenzimidazole as the lower axial ligand coordinated to the central cobalt atom and one of several upper axial ligands CN, OH, methyl, adenosyl, and others. The term vitamin B12 referred originally to the form of cobalamin that was first isolated and characterized, which was cyanocobalamin.
The designation of folate in the B-vitamin numbering system is B9, but this term is rarely used. For 2 related reasons, the nutrients folate vitamin B-9 and vitamin B B12, cobalamin are inextricably linked.
Metabolically, both vitamins participate in an enzyme reaction involving one-carbon metabolism in which the substrate homocysteine is converted to methionine through transfer of a methyl group from the cosubstrate methyltetrahydrofolate. This enzyme, methionine synthase, requires vitamin B in the form of methylcobalamin as a cofactor, and it is at the crossroads linking the important pathway of methylation through synthesis of S-adenosyl methionine and the pathways of purine and pyrimidine thymidine synthesis through generation of tetrahydrofolate.
Deficiency of either vitamin can result in perturbation of these 2 key pathways with consequent disruption of DNA synthesis caused by thymidine lack and resulting megaloblastic anemia. In addition, deficiency of these vitamins can result in disturbances of methylation, leading to effects on the nervous system and other organs. Because of the adverse consequences of such deficiencies, and the potential to prevent and correct them, the ability to assess folate and vitamin B status is important for public health.
The hematologic complications of folate or vitamin B deficiencies are identical so that for effective treatment it is critical to have a reliable means to discriminate between these 2 vitamin deficiencies.
The ability to detect or confirm the presence of folate or vitamin B deficiency and to distinguish one from the other rests on dependable laboratory testing.
Another aspect of the importance of laboratory testing relates to the importance of monitoring the efficacy of intervention programs designed to prevent or ameliorate deficiencies of folate and vitamin B The methods used to assess folate and vitamin B status fall broadly into 1 of 2 categories. In one, concentrations of the vitamins are measured directly in the blood and in the other, metabolites that accumulate as a result of the vitamin deficiencies are measured.
Tests to determine the presence of folate or vitamin B deficiency may be used singly or in combination to establish the nutritional status and prevalence of deficiencies of the vitamins in various populations. Deficiencies of folate or vitamin B ultimately cause structural or morphologic changes that most conspicuously become evident through changes in the blood, including anemia with associated morphologic changes.
In essence, tests to assess folate or vitamin B status can also be used as surrogates for monitoring the efficacy of intervention. However, correction of an abnormal laboratory value does not necessarily connote a successful outcome of the intervention unless there is evidence of objective improvement in the health of an individual or there is a reduction of disease prevalence in a population.
Before discussing the indicators for assessing folate and vitamin B status, the causes of deficiency of these vitamins will be reviewed briefly. In some situations, such as chronic generalized malabsorption or malnutrition, deficiencies of both vitamins may coexist. A detailed consideration of all causes of folate or vitamin B deficiency lies beyond the scope of this communication, and for this, the reader is referred to several recent reviews of the subject 1 — 3.
Briefly, causes of deficiencies of these vitamins may be classified into 3 broad categories: In general, folate deficiency is most often the result of decreased intake and is more common in developing and socioeconomically distressed countries. Situations in which inadequate intake is further compounded occur when there is an increased folate requirement. Such situations arise in physiologic conditions including pregnancy, lactation, and prematurity as well as among populations in which there is a high prevalence of chronic hemolytic anemias, typically caused by hemoglobinpathies, most notably sickle cell anemia and the thalassemias.
Other conditions associated with increased cell turnover such as leukemias, aggressive lymphomas, and other tumors associated with a high proliferative rate can also cause increased folate demand 3. Generalized exfoliative dermatitis also causes folate deficiency through increased loss of folate, as does hemodialysis. Causes of decreased intake include poor nutrition, old age, poverty, and alcoholism.
Less commonly, inadequate intake can arise through inappropriate and prolonged hyperalimentation or other use of synthetic diets as well as the use of goat milk, which is low in folate. Although less common, impaired absorption may be a cause of folate deficiency, and it occurs in a variety of small intestinal diseases that include both tropical and nontropical sprue adult celiac disease and inflammatory bowel disease.
Congenital selective malabsorption of folate is a rare but important disorder that has been found to be caused by mutations in the recently described proton-coupled folate transporter 3.
As a matter of public health, the widespread implementation of folic acid fortification programs in many countries around the world has drastically reduced the prevalence of folate deficiency in those countries 4 and has tilted the distribution of causes of deficiency away from inadequate intake and toward increased requirements.
Low vitamin B status denotes a condition in which laboratory tests indicate depletion of vitamin B stores as judged by being outside of the normal reference range.