Cianocobalamina

cyanocobalamin is evaluated for the following indications with varying evidence strength: Vitamin B12 deficiency anaemia (pernicious anaemia) (evidence tier A), B12 deficiency with neurological symptoms (evidence tier A), Chronic fatigue (evidence tier F). See the full indication matrix with dosing and citations above on this page.

Common side effects of cyanocobalamin (≥ 1 in 100): Injection site pain, Allergic reactions (urticaria, pruritus). See the Safety section for uncommon and serious reactions.

FDA category A. Safe at recommended doses. Pregnant vegans and women with confirmed deficiency require supplementation – maternal B12 deficiency increases the risk of neural tube defects and developmental delay in the foetus.

Transfers into breast milk. Maternal B12 deficiency (especially in vegan mothers) causes infant deficiency during breastfeeding – maternal supplementation is required.

cyanocobalamin is contraindicated in: Hypersensitivity to cyanocobalamin or other components; Polycythaemia vera, erythrocytosis; Thromboembolic disease (relative). Full list in the Safety section.

in patients with normal B12, there is no effect on energy or performance. Popular vitamin cocktails and B12 drips for healthy people lack evidence and carry injection-related risks.

both forms are effective for deficiency correction. Methylcobalamin is more expensive, and direct RCTs showing superiority are absent. Cyanocobalamin converts to active coenzyme forms in the body.

the 2018 Cochrane review showed comparable efficacy of high-dose oral and parenteral routes. In neurological involvement and severe anaemia, injections are preferred in the first 2–4 weeks, then switching to tablets is possible.