Vitamin B12 (Adenosylcobalamin) vs Vitamin B12 (Cyanocobalamin)
Two forms of the same compound. What differs is how much of it your body absorbs, how well you tolerate it and what it costs per month.
Side by side
Green marks the better value| Vitamin B12 (Adenosylcobalamin) | Vitamin B12 (Cyanocobalamin) | |
|---|---|---|
| Bioavailability | 80% | 70% |
| Safety rating | 10/10 | 9/10 |
| Cost per month | $60 | $8 |
| Daily dose | 1000-3000 mcg | 250-1000 mcg |
| Best timing | Morning with food | Morning with food |
| Evidence level | B | A |
Verdict
Vitamin B12 (Adenosylcobalamin) wins on 2 of the measurable metrics.
It absorbs at 80% against 70%, which is the number that decides how much of the dose actually reaches you. It does cost more per month — that is the trade-off.
What actually differs
Vitamin B12 (Adenosylcobalamin)
Mitochondrial coenzyme form of B12 essential for energy metabolism and cellular respiration
- Mitochondrial specific
- Active form
- Energy focused
- Complements methylB12
- Very expensive
- Limited availability
- Less stable
- Limited research vs other forms
Vitamin B12 (Cyanocobalamin)
Most stable and researched form of vitamin B12, requiring conversion to active forms in the body
- Most stable
- Least expensive
- Most research
- Long shelf life
- Requires conversion
- Contains cyanide group
- Lower bioactivity
How these numbers are read
- Bioavailability is the share of the dose that reaches your bloodstream — the single most useful number when choosing a form.
- Safety rating reflects tolerance at normal doses, not toxicity risk.
- Cost is per month at the typical daily dose, so a cheaper form taken at double the dose is not cheaper.
- Evidence level A means the form itself was studied, not just the parent compound.
Where to buy
Both forms deliver the same compound — pick by the numbers above, then check the label matches.
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Common questions
Which is better, Vitamin B12 (Adenosylcobalamin) or Vitamin B12 (Cyanocobalamin)?
Vitamin B12 (Adenosylcobalamin) absorbs better — 80% against 70%. Absorption decides how much of the dose actually reaches you, so it usually matters more than the milligrams printed on the label.
What is the difference between Vitamin B12 (Adenosylcobalamin) and Vitamin B12 (Cyanocobalamin)?
Both deliver the same active compound. They differ in how well the body takes them up, how they are tolerated and what a month costs: $60 against $8.
Can you take Vitamin B12 (Adenosylcobalamin) and Vitamin B12 (Cyanocobalamin) together?
You can, but there is rarely a reason to. Two forms of the same compound stack the same active dose, so the usual approach is to pick the better absorbed one and dose it properly.