Vitamin B12

Overview

Vitamin B12 is an essential water-soluble vitamin built around a corrin ring coordinating a central cobalt atom — the only known biological molecule to contain cobalt, and the largest and most structurally complex of the vitamins. Cyanocobalamin is the synthetic form most commonly used in supplementation and in the published trial literature; it is converted in the body to the active coenzyme forms methylcobalamin and adenosylcobalamin. Unlike most compounds in this database, the essentiality of B12 is entirely settled science; the published research questions concern optimal dose, route and the populations in which supplementation produces measurable benefit.

For research use only · Not FDA/EMA approved · Not for human consumption

Mechanism of Action

Vitamin B12 functions as a cofactor for two enzymes in human metabolism. Methylcobalamin is required by methionine synthase, which converts homocysteine to methionine, linking B12 status to folate metabolism and to circulating homocysteine concentration. Adenosylcobalamin is required by methylmalonyl-CoA mutase, which converts methylmalonyl-CoA to succinyl-CoA in the catabolism of certain fatty acids and amino acids. Deficiency accordingly raises both homocysteine and methylmalonic acid, and published work uses these metabolites as functional status markers, which is discussed in the literature as more informative than serum B12 concentration alone.

For research use only · Not FDA/EMA approved · Not for human consumption

Key Research Areas

• Oral dose-finding in older adults with deficiency
• Sublingual supplementation in vegans and vegetarians
• Alternative delivery routes including fortified formulations
• Prevention of deficiency in at-risk populations
• B vitamins and homocysteine in stroke prevention research

For research use only · Not FDA/EMA approved · Not for human consumption

Published Studies (4 cited)

For research use only · Not FDA/EMA approved · Not for human consumption

Dosage in Published Research

Published trials span a wide dose range depending on route and population. Oral dose-finding work in deficient older adults examined doses well above nutritional requirements, reflecting the low fractional absorption of oral B12 when intrinsic factor-mediated uptake is saturated or impaired. Sublingual trials have compared distinct dosages in marginally deficient vegetarians and vegans. Parenteral protocols follow separate clinical schedules. All figures are reported from published clinical literature for reference purposes only.

For research use only · Not FDA/EMA approved · Not for human consumption

Storage & Handling

Store protected from light — cyanocobalamin solutions are photosensitive and degrade on light exposure, which is why amber containers are standard in published protocols. Store the solid at room temperature or refrigerated in a sealed, light-protected container. Solutions should be refrigerated at 2–8°C and protected from light. Handle under laboratory conditions using appropriate PPE.

For research use only · Not FDA/EMA approved · Not for human consumption

Safety Profile (Literature Only)

Vitamin B12 is water-soluble with excess excreted renally, and the published literature describes a wide margin of tolerability; no tolerable upper intake level has been set by the principal nutrition authorities on the basis of the available evidence. Published clinical guidance emphasises one practically important point: supplementation can correct the haematological signs of deficiency while permitting neurological consequences to progress if the deficiency is not properly diagnosed and monitored. This compound is supplied for laboratory research use only.

For research use only · Not FDA/EMA approved · Not for human consumption