From the Guidelines
The best source of methylated vitamin B12 (methylcobalamin) is through supplements, specifically sublingual tablets or oral capsules, as they provide a direct and absorbable form of the vitamin, especially for individuals with dietary restrictions or deficiencies. When considering sources of methylated vitamin B12, it's essential to prioritize forms that are readily absorbable and usable by the body. Animal-based foods such as liver, clams, fish, meat, eggs, and dairy products are natural sources, but for those requiring higher concentrations or with specific dietary needs, supplements are more reliable.
Methylcobalamin supplements are available in various forms, including sublingual tablets, oral capsules, and injections, typically in doses ranging from 500-5000 mcg daily 1. The sublingual form is often preferred for its better absorption rate, bypassing potential digestive issues. Methylcobalamin is considered superior to cyanocobalamin because it is the active form of B12 that is ready for immediate use by the body without requiring conversion, making it beneficial for people with methylation issues or certain genetic variants like MTHFR.
For individuals with severe deficiencies, healthcare providers might recommend B12 injections, usually starting with more frequent doses before transitioning to maintenance doses 1. It's crucial for vegans and vegetarians to consider supplementation since plant foods do not naturally contain B12. The guidelines for treating vitamin B12 deficiency emphasize the importance of immediate treatment, especially in cases with possible neurological involvement, and highlight the role of hydroxocobalamin injections in management 1. However, for the purpose of sourcing methylated B12, supplements and certain foods remain the primary considerations.
From the Research
Sources of Methylated Vitamin B12
- Methylcobalamin (MeCbl) is a form of vitamin B12 that can be found in various sources, including supplements and certain foods 2.
- Sublingual methylcobalamin has been shown to be an effective treatment for vitamin B12 deficiency in children aged 0-3 years, with efficacy comparable to oral and intramuscular cyanocobalamin 3.
- Vitamin B12 deficiency can be caused by inadequate intake, inadequate bioavailability, or malabsorption, and can affect individuals of all ages, with elderly individuals and those with restricted dietary intake being at higher risk 4.
- Methylcobalamin is one of four forms of vitamin B12 used for supplementation, along with cyanocobalamin, hydroxocobalamin, and 5'-deoxyadenosylcobalamin, each with its own biochemical role, bioavailability, and efficacy 5.
Administration Methods
- Sublingual administration of vitamin B12 has been shown to be effective in restoring B12 levels, with some studies suggesting it may be superior to intramuscular injection 6.
- The oral route has been proven to be comparable to the intramuscular route for rectifying vitamin B12 deficiency 2.
- Sublingual methylcobalamin treatment has been found to be as effective as oral and intramuscular cyanocobalamin treatments in children aged 0-3 years 3.