Learn all about Vitamin B12 (Cobalamin)
What is Vitamin B12 (Cobalamin)?
Revitalise energy & support brain function with active vitamin B12. Essential for DNA synthesis & red blood cell formation. Feel recharged!
Benefits of Vitamin B12 (Cobalamin)
"B12 deficiency remains worryingly common, particularly in older adults and those with dietary restrictions. What makes it especially concerning is that neurological damage can occur even before blood tests show frank deficiency, and once symptoms develop, the damage may be irreversible despite treatment. For these high-risk groups, supplementation is often the safest approach rather than waiting for symptoms to appear."
- Dr. Sally Pacholok, RN, BSN, co-author of 'Could It Be B12?: An Epidemic of Misdiagnoses' (source)
How to use Vitamin B12 (Cobalamin)
Dosage
2.4mcg daily for adults (recommended dietary allowance); 25-1000mcg daily for therapeutic purposes depending on condition and severity of deficiency
Timing
Any time of day, but preferably with meals for optimal absorption; sublingual forms may be taken on empty stomach
Notes
Cyanocobalamin is most stable in supplements; methylcobalamin and adenosylcobalamin are active forms that may benefit certain populations; injections recommended for severe deficiency or absorption issues
Who should take Vitamin B12 (Cobalamin)?
- Vegans and strict vegetarians due to absence in plant foods
- Adults over 50 with decreased stomach acid production affecting absorption
- People with gastrointestinal disorders affecting nutrient absorption (Crohn's, coeliac disease)
- Those taking medications that deplete B12 (metformin, proton pump inhibitors)
- Individuals with genetic mutations affecting B12 metabolism (MTHFR variants)
How does Vitamin B12 (Cobalamin) work?
Vitamin B12 functions as a cofactor for two critical enzymes: methionine synthase (converting homocysteine to methionine, important for DNA synthesis) and methylmalonyl-CoA mutase (involved in fatty acid metabolism). After absorption with intrinsic factor in the terminal ileum, B12 binds to transcobalamin for transport through the bloodstream. In cells, it supports the conversion of folate to its active form, enabling DNA synthesis and red blood cell maturation. In the nervous system, B12 is essential for maintaining myelin, the protective sheath around nerves that enables proper signal transmission.
Frequently asked questions
Natural sources of Vitamin B12 (Cobalamin)
B12 occurs naturally only in animal products, with highest concentrations in liver (85mcg per 85g serving), clams (84mcg per 85g), nutritional yeast (fortified, 24mcg per tablespoon), and sardines (8mcg per 85g). Eggs, dairy products, and meat provide moderate amounts, with beef containing approximately 2mcg per 85g serving. Plant sources contain B12 only when fortified, including certain non-dairy milks, breakfast cereals, and meat substitutes. Some nutritional yeasts naturally contain B12 due to bacterial synthesis during production.
Potential side effects & risks
Warnings
Can mask folate deficiency symptoms while allowing neurological damage to progress; those with Leber's disease (hereditary optic nerve atrophy) should avoid; cobalt sensitivity may cause allergic reactions to cyanocobalamin
Side effects
Generally well-tolerated even at high doses; occasional mild diarrhoea, itching, or skin rash; rarely causes acne-like skin eruptions with high-dose injections
Interactions
May reduce effectiveness of certain medications including chloramphenicol, proton pump inhibitors, and metformin; high doses may interfere with some lab tests and potentially interact with folate metabolism