Vitamin B12 Deficiency Test
Vitamin B12 deficiency is a reduction in vitamin B12 from inadequate dietary intake or impaired absorption. The condition is commonly asymptomatic, but can also present as anemia characterized by enlarged blood corpuscles with characteristic changes in neutrophils, known as megaloblastic anemia.
In serious cases deficiency can potentially cause severe and irreversible damage to the nervous system, including subacute combined degeneration of spinal cord.
The anemia is thought to be due to problems in DNA synthesis, specifically in the synthesis of thymine, which is dependent on products of the MTR reaction. Other blood cell types such as white blood cells and platelets are often also low. Bone marrow examination may show megaloblastic hemopoiesis. The anemia responds completely to vitamin B12; the neurological symptoms (if any) respond partly or completely, depending on prior severity and duration.
Presentation
Early and even fairly pronounced deficiency does not always cause distinct or specific symptoms. Common early symptoms are tiredness, a decreased mental work capacity, weakened concentration and memory, and irritability and depression.
Sleep disturbances may occur, because B12 may be involved in the regulation of the sleep wake cycle by the pineal gland (through melatonin).
Neurological signs of B12 deficiency, which can occur with or without anemia, include sensory disturbances (due to damage to peripheral nerves caused by demyelination) and irreversible nerve cell death. Symptoms include numbness and/or tingling of the extremities, altered proprioception, impaired sense of smell, loss of appetite (anorexia), disturbed coordination and, if not treated in time, an ataxic gait especially in the dark when there is less visual reference. In extreme cases, B12 deficiency can lead to a syndrome known as subacute combined degeneration of spinal cord.
B12 deficiency can also cause symptoms of mania, psychosis, fatigue, memory impairment, irritability, depression and personality changes.
B12 status may be associated with the onset and course of Alzheimer's disease. Some studies have found no relationship, while several recent studies indicate a relationship between B12, homocysteine, and Alzheimer's. B12 status is routinely measured at the time of Alzheimer's diagnosis, and there is some indication that ongoing measurements may be useful to detect the development of a severe deficiency. In addition to checking serum B12, checking the levels of other compounds (particularly methylmalonic acid) may be necessary to accurately detect a deficiency state, because serum levels do not necessarily correlate with efficient utilization of B12.
Studies showing a relationship between clinical depression levels and deficient B12 blood levels in elderly people are documented in the clinical literature.
Bipolar disorder appears to genetically co-segregate with the hereditary B12-deficiency disorder pernicious anemia .
Science Daily reported that "a deficiency of B-vitamins may cause vascular cognitive impairment, according to a new study by the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University." Aron Troen, PhD, said that: "The vascular changes occurred in the absence of neurotoxic or degenerative changes. Metabolic impairments induced by a diet deficient in three B-vitamins — folate, B12 and B6 — caused cognitive dysfunction and reductions in brain capillary length and density in our mouse model."
The following symptoms have been recorded, beginning with those perhaps most likely to be indicative of B12 deficiency.
1. Itchy or tingling tongue. The tongue suddenly itches from time to time without warning. This occurs on the edge of the tongue, along one side or the other or at the tip. Some individuals experience stinging, pain, or tingling instead of itching.
2. White spots in the skin, resulting from melanin becoming absent in the area. These often occur on the outside of the forearm, but may occur in other places. The longer these spots are there, the whiter they get. As time goes by, the spots become very dry and flaky to the extent that small raw spots of skin may be exposed.
3. Sharp stabbing, tingling pain in the palm of one or both hands. This occurs suddenly and for no apparent reason in a spot directly below the ring finger, approximately where the first palm crease is. If B12 deficiency is not treated, a tingling pain may begin to occur along the outside edge of the hand, starting from the wrist. This pain occurs when the wrist is extended.
4. Sores at the corners of the mouth, sometimes extending along the edge of the lip. These are raw spots, not blisters, and they tend to come and go.
5. Nerve shock in the side of the body. It can be felt coming on a few seconds before it hits, and then it hits almost like a mild but deep electric shock and quickly subsides. It can occur at the side of either hip or on either side of the upper body, along the ribs. It can occur consecutively in at least two or three locations, one right after the other.
6. Shortness of breath, but without chest pain. This can occur when walking just a few yards.
7. Eye twitch, usually in one eye or the other. It can occur on the eyelid or just below the eye.
8. Facial pain, usually on only one side of the face at a time. This pain varies so much that it would be difficult to describe all the possibilities. This can present as a dull pain in the cheek bone right underneath an eye, or a sharp shooting pain across the forehead, sometimes coming downward from the scalp to the edge of the nose by the eye.
9. Tingling along the back of one or both thighs, starting at the hips and shooting downward.
10. Memory loss and/or disorientation.
11. Migraine headaches. These may be preceded by a temporary blind spot in the center of the field of vision, usually lasting about ten minutes, and sometimes followed by facial pain under the eyes. After the blind spot vanishes, there may be zigzag streaks through the vision that may last up to hours. Even in the same person, there may be extreme variations in the headaches themselves. They may be quite severe with nausea or they may be virtually nonexistent.
Migraines of most individuals have causes other than B12 deficiency, but migraines of certain individuals diminish or stop completely after they are treated for B12 deficiency.
12. Irritability and/or depression and/or personality changes.
Causes
- Inadequate dietary intake of vitamin B12. As the vitamin B12 occurs naturally only in animal products (eggs, meat, milk); a vegan diet can produce a deficiency unless one uses supplements or eats enriched food.
- Selective impaired absorption of vitamin B12 due to intrinsic factor deficiency. This may depend on loss of gastric parietal cells in chronic atrophic gastritis (in which case, the resulting megaloblastic anaemia takes the name of "pernicious anaemia"), or on wide surgical resection of stomach (such as in bariatric surgery), or on rare hereditary causes of impaired synthesis of intrinsic factor. Celiac disease which affects around one percent of the European population may cause impaired absorption of this vitamin.
- Impaired absorption of vitamin B12 in the setting of a more generalised malabsorption or maldigestion syndrome. This includes any form of structural damage or wide surgical resection of the terminal ileum (the principal site of vitamin B12 absorption), forms of achlorhydria (including that artificially induced by drugs such as proton pump inhibitors), as well as bacterial overgrowth (such as in blind loop syndrome).
- Chronic intestinal infestation by the fish tapeworm Diphyllobothrium , that competes for vitamin B12, seizing it for its own use and therefore leaving insufficient amount for the host organism. This is mostly confined to Scandinavia and parts of Eastern Europe (for example, in preparers of gefilte fish, who would acquire the tapeworm by nibbling bits of fish before it was cooked while making the Eastern European delicacy).
- The diabetes medication, metformin may interfere with B12 dietary absorption.
- Hereditary causes such as severe MTHFR deficiency, homocystinuria, and transcobalamin deficiency.
- Some studies have shown that giardiasis, or similar parasite should be considered as a cause of Vitamin B12 deficiency, this a result of the problems caused within the intestinal absorption system.
Incidence/prevalence
Recent research indicates that B12 deficiency is far more widespread than formerly believed. A large study in the US found that 39 percent of studied group of 3,000 had low values. This study at Tufts University used the B12 concentration 258 pmol/l (= 350 pg/liter) as a criterion of "low level". However, a recent research has found that B12 deficiency may occur at a much higher B12 concentration (500–600 pg/l). On this basis Mitsuyama and Kogoh proposed 550 pg/l, and Tiggelen et al. proposed 600 pg/l. Against this background, there are reasons to believe that B12 deficiency is present in a far greater proportion of the population than 39% as reported by Tufts University.
In the developing world the deficiency is very widespread, with significant levels of deficiency in Africa, India, and South and Central America. This is due to low intakes of animal products, particular among the poor. The increased bacterial load due to poor sanitation, unprocessed/unsterilized food, or other sources of dietary contamination could also lead to pathogen-related malabsorption issues.
B12 deficiency is even m
Anaemia due to vitamin B12 deficiency (pernicious ...
In cases of vitamin B12 deficiency, the red blood cells will be the usual colour but larger than normal. If the blood test shows a low vitamin B12 count, it must be established ...
Vitamin B12 Deficiency Anemia-Topic Overview
Vitamin B12 deficiency anemia usually happens when the digestive system is not able to absorb ... Topic Overview; Symptoms; Exams and Tests; Treatment Overview; Home Treatment
Vitamin B12-deficiency anaemia
Bupa health factsheet - People with vitamin B12-deficiency anaemia have symptoms ... If you have low levels of vitamin B12, you may need to have a test to look for the antibodies that ...
Vitamin B12 Deficiency Anemia-Exams and Tests
If vitamin B12 deficiency anemia is suspected, your doctor will do a physical exam and ask questions about your medical history and symptoms.
Vitamin B12 Deficiency
Vitamin B12 deficiency can be due to malabsorption of dietary B12 despite normal ... with dual protein bound aqueous vitamin B12 absorption test in subjects with low serum vitamin B12 ...
B12 Vitamin Deficiency Home Collection Urine Test Kit
B12 Vitamin Deficiency Home Collection Urine Test Kit and other health test kits. TestCountry.com provide information as well as secure shopping environment for your test kit needs
Vitamin B12 Deficiency
Overview of Vitamin B12 and folate deficiency and tests used to diagnose and monitor it
Vitamin B12 Deficiency Anemia - Exams and Tests ...
If vitamin B12 deficiency anemia is suspected, your doctor will do a physical exam and ask questions about your medical history and symptoms. You will also have blood tests, such ...
vitamin B12 deficiency - definition of vitamin B12 ...
Schilling test subacute combined degeneration subacute combined degeneration of ... vitamin B12 deficiency vitamin B12 neuropathy vitamin B2 vitamin B3 Vitamin B6
BetterTesting.org | Vitamin B12 and folate deficiency
There is little information from large scale consensus statements or large clinical trials. The guidance below is derived from a small number of reviews supplemented by ...