Vitamin B12
supplementcobalamin · methylcobalamin
Vitamins
Research status · Dietary supplement
Dietary supplement / essential nutrient; deficiency is confirmed with a blood test.
B12 supports red blood cells and nerve function. Deficiency is most common with plant-based diets, older age, or acid-reducing medications — a blood test tells you where you stand.
How it works
Cofactor for DNA synthesis, red-blood-cell formation, and neurological function.
Commonly discussed use cases
- Plant-based diets
- Confirmed low levels
- Energy (when deficient)
Supposed / potential benefits
- Corrects deficiency; energy benefits mainly apply when levels were low
Common side effects
- Well tolerated; excess is excreted
Warnings & contraindications
- Fatigue has many causes — test rather than assume B12 is the fix
Typical timing considerations
Any time of day; follow product guidance.
Administration route
Oral (injections are clinician-directed for confirmed deficiency)
Questions to ask your clinician
- Should we check my level first?
- Do any of my medications affect B12 absorption?
Commonly tracked in Reta
Tracking fields organize user-entered, clinician-directed routines — Reta never recommends or computes doses.
Sources
Track this in Reta
Beta members get a ready-made tracker for Vitamin B12 — schedule, dose log, reminders, and check-ins — for organizing a clinician-directed routine. Personal tracking is available to everyone during the Public Beta.
Reta is a tracking and education tool — not a medical provider. Nothing here is a diagnosis, treatment, prescription, or dosing recommendation. Peptides and medications should only be used under the direction of a licensed clinician. Talk to a qualified clinician before starting, stopping, combining, or changing anything. Many compounds below are not FDA-approved for human use; some are investigational or sold through unregulated channels where purity and dosing are not guaranteed.