Is oral vitamin B₁₂ therapy effective?

Finally, the earliest studies on oral vitamin B₁₂ replacement using low doses of vitamin B₁₂ were failures, which gave evidence to the thinking that the only way vitamin B₁₂ could be replaced would be via parenteral administration.

Dr. Paauw is professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington Medical School. He is the Rathmann Family Foundation Chair in Patient-Centered Clinical Education. Contact Dr. Paauw at dpaauw@uw.edu.