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Vitamin B12
•Last Updated: March 16, 2024
Vitamin B12 is an essential water-soluble vitamin that plays a role in neurological function and is important for DNA synthesis.
Vitamin B12 is most often used for
Last Updated:March 16, 2024
Vitamin B12 is a water-soluble B vitamin that plays a crucial role in one-carbon metabolism and various metabolic processes in the body. It acts as a cofactor in the production of methionine, an amino acid that is essential for DNA synthesis.
Vitamin B12 is primarily used to combat general fatigue and may benefit individuals with myalgic encephalomyelitis (ME/CFS) and various types of neuropathy. It is also crucial during the first trimester of pregnancy to prevent neural tube defects, though its effectiveness for cognitive symptoms in neurodegenerative diseases and viral infections requires further research.
Vitamin B12 is generally safe and has low toxicity risk, but high levels may be associated with increased cancer risks, particularly prostate and lung cancer in certain populations. Additionally, the relationship between vitamin B12 and cardiovascular disease remains unclear, and conflicting evidence exists for its effect on mortality and outcomes.
Vitamin B12 is essential for various chemical reactions in the body, including the synthesis of methionine and the production of myelin sheaths around nerves, which are crucial for nerve signal transmission. A deficiency in vitamin B12 can lead to megaloblastic anemia and neurological symptoms, including peripheral neuropathy.
Note that Vitamin B12 is also known as:
- Cyanocobalamin
- Cobalamin
- Methylcobalamin
- 5-Deoxyadenosylcobalamin
- 5-deoxyadenosylcobalamin
- Cobamamide
- Dibencozide
- Hydroxocobalamin
The Recommended Daily Allowance (RDA) of vitamin B12 is 2.4 μg for adults without known health conditions. During pregnancy, the RDA increases to 2.6 μg.[1] For children 8 years and under, the RDA is 1.2 μg.[1] Supplementing with B12 is probably not helpful in people who are able to get enough of the vitamin through their diet and have no difficulty with absorption.
Supplements that are available over the counter contain 500–2000 μg of vitamin B12 per tablet. Long-term use is not recommended without monitoring of vitamin B12 levels.
For replenishing stores of vitamin B12, 1000 μg should be given by intramuscular injection three times per week for two weeks. This can then be done weekly for four weeks, then once monthly. In cases where absorption is not an issue, the maintenance dose can also be given orally.[2]
Research FeedRead all studies
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