Nobody has ever run methylcobalamin against cyanocobalamin
Cyanocobalamin at 1 to 2 milligrams a day cleared deficiency, and a separate trial of methylcobalamin saw the same markers fall. No trial gave the two forms to the same people.
What the study found
Both B12 forms fixed the blood work, never in the same trial
Cyanocobalamin at 2 milligrams a day corrected blood and nerve signs as fast as injection, and at 1000 micrograms a day cleared deficiency in people who could not absorb B12 at all. A separate trial gave methylcobalamin and saw the same markers fall. None ran the two against each other.
The caveat · No proof the two forms are equal
None of these trials set out to compare the forms, so this is an absence of evidence that one beats the other, not evidence they are the same. They enrolled different patients on different schedules, which is what a real comparison would have to hold constant.
What we don't know
None of these trials set out to compare the forms, so this is an absence of evidence that one beats the other, not evidence they are the same. They enrolled different patients on different schedules, which is what a real comparison would have to hold constant.