Vitamin B12 in Health and Disease
Vitamin B12 deficiency anemia can cause symptoms including weak If you have a follow-up appointment, write down the date, time, and purpose for that visit. You need to take in a well-balanced mix of nutrients to maintain optimal health, and sometimes understanding the interactions between the essential vitamins. Dec 11, Vitamin B12 deficiency is associated with anemia, megaloblastosis, neuropathy, between serum folate and vitamin B12 status in relation to anemia, Our goal in the present study was to determine whether higher folate.
The Schilling test was the classical procedure for assessing the absorption of vitamin B12 but is now rarely used.
As there has been no replacement a number of individual tests must be used to diagnose the cause of vitamin B12 deficiency. Tests that diagnose atrophic gastritis, a common cause of vitamin B12 malabsorption, include gastroscopy or serum gastrin and pepsinogen levels.
Specific tests for pernicious anaemia include IF antibodies and serum gastrin estimation. MMA and tHcy are better markers of vitamin B12 status, although they are not appropriate for testing absorption [ 16 ]. An overview of the medical management of vitamin B12 deficiency can be found in a recent article by Ralph Carmel [ 17 ]. Food Sources and Bioavailability of Vitamin B12 Vitamin B12 is synthesised by certain bacteria in the gastrointestinal tract of animals and is then absorbed by the host animal.
Vitamin B12 is concentrated in animal tissues, hence, vitamin B12 is found only in foods of animal origin [ 11 ].
Relationships of vitamin B1, B12, folate and the cognitive ability of the Thai rural elderly.
There are no naturally occurring bioactive forms of vitamin B12 from plant sources. Some plant foods contain added vitamin B12 and others e. Some foods that are contaminated or fermented by bacteria e. A number of methods have been used to determine the vitamin B12 content of foods. Microbiological assays using vitamin B12 requiring bacteria were used, however, they are no longer the reference method as measurement uncertainty is high. Radio isotope dilution assays with labeled vitamin B12 and hog IF are used [ 20 ].
Further advances are expected with the development of more specific monoclonal antibodies tests using specific binding proteins [ 21 ]. As outlined previously, vitamin B12 absorption is complex and there are adverse changes with age.
In view of the technical challenges and biological factors, there is little data on the bioavailability of dietary vitamin B12 in humans. It is thought that 1. In normal humans the absorption of vitamin B12 from foods has been shown to vary depending on the quantity and type of protein consumed [ 19 ].
Vitamin B12 from foods appear to have different absorption rates with better absorption from chicken and beef as compared to eggs.
Vitamin B12 And Folic Acid
Studies assessing absorption of food bound vitamin B12 from whole foods are described in Table 1. However, the US and Australian Nutrient Reference Values suggest that older adults with atrophic gastritis may require higher intakes of vitamin Brich foods, vitamin B12 fortified foods or supplements [ 322 ]. The US Institute of Medicine has recommended that adults over 51 years consume most of their vitamin B12 from fortified foods or from supplements, again recognising the high rates of malabsorption due to gastritis that occurs with age.
Low TSH levels could be a consequence of AD-related neurodegeneration leading to reduced hypothalamic thyrotrophin-releasing hormone TRH secretion or decreased pituitary responsiveness and consequently low TSH levels.
The thyroid dysfunction with elevated thyroid hormone levels appears to be associated with increased necrotic neuron death[ 34 ] and oxidative stress. Raised TC observed in all the 3 dementia groups in the present study is supported by the findings of Notkola et al. We also found that blood levels of vitamin B12 and folate also had negative correlation with MMSE score. At present, no effective explanation can be given for the same.
The explanation may lie in the limitations or shortfalls of the study. We may put forward 3 reasons: One, vitamin B12 and folate levels were measured in our study at the time when patient had developed dementia; second, total vitamin B12 levels in the plasma may not signify the deficiency state of vitamin B12 at the tissue level; and finally, to establish that such correlation sample size should have been much larger.
However, Li et al. Based on the findings of the present study, it can be concluded that the low levels of these biochemical markers, that is, vitamin B12 and folate may be relevant to the clinical course of AD and VaD and should be considered for therapeutic intervention. However, it remains an open question whether or not these interventions in terms of B vitamin supplementation a combination of folate, vitamin B12, and vitamin B6 will improve cognitive functions or retard the rate of cognitive decline in older adults with or without dementia.
Hence at present, B vitamin supplementation should be reserved for the treatment of documented deficiency states, but not expressly for the prevention or treatment of cognitive disorders, including AD. Footnotes Conflict of Interest: The worldwide challenge of the dementias: A role for B vitamins and homocysteine?
Folate, vitamin B12, and serum total homocysteine levels in confirmed Alzheimer disease. Vitamin B12 and folate status in acute psychogeriatric inpatients: Affective and cognitive characteristics of a vitamin nondeficient population. Time dependency of cognitive recovery with cobalamin replacement: Report of a pilot study. Kaferle J, Strzoda CE. Cecil Textbook of Medicine. Arendt JF, Nexo E.
Vitamin B12 Deficiency: Recognition and Management - - American Family Physician
Cobalamin related parameters and disease patterns in patients with increased serum cobalamin levels. The pathophysiology of elevated vitamin B12 in clinical practice. Laboratory testing for cobalamin deficiency in megaloblastic anemia.
Pathophysiology and laboratory diagnosis of pernicious anemia. Moridani M, Ben-Poorat S. Laboratory investigation of vitamin B12 deficiency. How I treat cobalamin vitamin B12 deficiency. Oral vitamin B12 versus intramuscular vitamin B12 for vitamin B12 deficiency. Cochrane Database Syst Rev. Effective treatment of cobalamin deficiency with oral cobalamin.
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