Vitamin B12 (methylcobalamin vs cyanocobalamin) and energy
What 3 graded rows on vitamin b12 (methylcobalamin vs cyanocobalamin) agree on for energy, and where they differ. Counted side by side, never averaged.
Consensus finder Rows from the Vitamin B12 (methylcobalamin vs cyanocobalamin) page, reviewed Oct 21, 2026 How it decides
What the rows agree on
Each block and row is one graded row from the Vitamin B12 (methylcobalamin vs cyanocobalamin) page, with its PubMed record.
Your question
Vitamin B12 (methylcobalamin vs cyanocobalamin) and energy
3 rows · 303 peopleMostly no difference: 2 of 3 rows, and most of the people. 1 found an improvement.
- CGrade C× 2
- DGrade D× 1
- Rows
- 3
- Trials
- 3
- At least: a review without a trial count
- People
- 303
- Pooled reviews may count some twice
Where they differ
From the rowsThe best-graded row, grade C, is a systematic review of 153 people (2018) and found no difference.
Only the 2 rows that found no difference include pooled reviews of several trials (1 of 2); the row that found an improvement is a single study.
The row that found an improvement ran longer (4 months) than the 2 rows that found no difference (4 weeks to 3 months).
Only the row that found an improvement names older adults in its population.
The rows
1 improved · 2 no difference- CGrade CRaising low blood B12: high-dose oral vs injection · No difference
Systematic review · n 153 · 2018 · 3 RCTs in people with vitamin B12 deficiency, mean ages 38.6–72
1,000–2,000 mcg/day oral · 3–4 months
At 1,000 mcg/day, no clinically relevant difference in serum B12 versus injections (2 trials); at 2,000 mcg/day (1 trial), serum B12 was 680 pg/mL higher with oral. Oral treatment cost less in one trial.
Row on the Vitamin B12 (methylcobalamin vs cyanocobalamin) page · PubMed 29543316 (opens PubMed)
- DGrade DRaising low blood B12: sublingual vs swallowed tablet · No difference
RCT · n 30 · 2003 · Adults with low serum cobalamin
500 mcg/day · 4 weeks
Serum B12 rose significantly in all groups with no difference between sublingual and oral routes.
Row on the Vitamin B12 (methylcobalamin vs cyanocobalamin) page · PubMed 14616423 (opens PubMed)
- CGrade CB12 status marker (methylmalonic acid) by oral dose · Improved
RCT · n 120 · 2005 · Older people with mild vitamin B12 deficiency
2.5, 100, 250, 500 or 1,000 mcg/day · 16 weeks
Methylmalonic acid fell 16%, 16%, 23%, 33% and 33% across doses. Daily doses of 647–1,032 mcg produced 80–90% of the maximum estimated reduction.
Row on the Vitamin B12 (methylcobalamin vs cyanocobalamin) page · PubMed 15911731 (opens PubMed)