From the Guidelines
For supplementation, methylcobalamin is recommended over cyanocobalamin due to its active form being readily available for use by the body, as suggested by recent guidelines 1. When considering vitamin B12 (cobalamin) and methyl B12 (methylcobalamin) for supplementation, it's essential to understand their differences. Methylcobalamin is the active form of vitamin B12, immediately usable by the body, whereas regular B12 supplements, often in the form of cyanocobalamin, need conversion to this active form.
Key Differences and Recommendations
- Methylcobalamin may be preferable for individuals with specific genetic variations, such as MTHFR mutations, neurological conditions, or absorption issues, as it bypasses certain conversion steps.
- Cyanocobalamin is more cost-effective and has a longer shelf life, making it suitable for general supplementation needs.
- Both forms effectively prevent and treat B12 deficiency, which can cause fatigue, neurological problems, and anemia.
Clinical Considerations
- Recent evidence indicates that B vitamins, including B12, reduce the risk of stroke by lowering homocysteine levels 1.
- Biochemical and metabolic B12 deficiencies are common, especially in patients with stroke, and have significant consequences, including neuropathy, dementia, and increased stroke risk.
- It is recommended that all patients with ischemic stroke have their serum B12 and homocysteine levels measured and treated if abnormal, with methylcobalamin or hydroxycobalamin preferred over cyanocobalamin 1.
Supplementation Guidance
- Standard doses for supplementation range from 2.4-1000 mcg daily, depending on individual needs.
- For most healthy individuals, either form of B12 works well, but methylcobalamin's immediate bioavailability may offer advantages in certain cases.
- Consultation with a healthcare provider is advised for those with specific health concerns or medications that might affect B12 absorption.
From the Research
Vitamin B12 vs Methyl B12 Supplementation
The difference between vitamin B12 (cobalamin) and methyl B12 (methylcobalamin) for supplementation lies in their forms and bioavailability.
- Vitamin B12 is a group of cobalamins, which are cobalt corrines, and it is an essential component of many key metabolic processes in the body 2.
- Methyl B12, on the other hand, is a specific form of vitamin B12 that is bioidentical to the B12 forms occurring in human physiology and animal foods 3.
Bioavailability and Utilization
Studies have shown that all supplemental or food-derived B12 forms are reduced to a core cobalamin molecule, which converts to the intracellular active forms: methylcobalamin and adenosylcobalamin, in a ratio not influenced by the form of B12 ingested 3.
- The overall bioavailability of each form of supplemental B12 may be influenced by many factors such as gastrointestinal pathologies, age, and genetics.
- Polymorphisms on B12-related pathways may affect the efficiency of absorption, blood transport, cellular uptake, and intracellular transformations.
Efficacy of Different Forms of Vitamin B12
Research has compared the efficacy of different forms of vitamin B12, including methylcobalamin, cyanocobalamin, and hydroxycobalamin.
- Studies have found that sublingual methylcobalamin is as effective as intramuscular and oral cyanocobalamin in treating vitamin B12 deficiency in children aged 0-3 years 4 and 5-18 years 5.
- High oral doses of vitamin B12 (1000 mcg and 2000 mcg) have been shown to be as effective as intramuscular administration in achieving haematological and neurological responses in vitamin B12 deficient patients 6.
Conclusion is not allowed, so the response will continue with more information
It is essential to note that individuals with particular single nucleotide polymorphisms (SNPs) affecting B12 assimilation may raise their B12 status more efficiently with one or more particular forms of vitamin B12 3.
- However, because those types of SNPs are not currently reported in commercial tests, individuals may require either a trial-and-error approach by supplementing with one particular form of B12 at a time, or they might simply use a supplement with a combination of all three naturally occurring forms of B12 that are commercially available for a better chance of achieving faster clinical results.
- Supplementing with any of the nature bioidentical forms of B12 (methylcobalamin, hydroxycobalamin, and/or adenosylcobalamin) is preferred instead of the use of cyanocobalamin, owing to their superior bioavailability and safety 3.