Oral B12 in Crohnʼs Disease: Is B12 by injection obsolete?
Bibliographic record
Abstract
It has been known for several years that there is an alternate pathway for vitamin B12 absorption that requires neither Intrinsic Factor nor the terminal ileum. It was established many years ago that resection of more than 60 cm of ileum almost always results in B12 malabsorption. To replace monthly B12 injections with daily high dose oral B12 in patients with Crohn's disease. Patients with more than 60 cm of ileal resection and/or disease were assumed to have B12 malabsorption. For patients with less than 60 cm ileal resection and/or disease, a Schilling test was performed. A trough serum B12 was obtained for each patient just prior to the due date of the next B12 injection. Oral B12 therapy was then started, with one tablet of 1200 mcg, once daily. Serum B12 levels were measured at 3 and 6 months. Six patients declined to switch to oral therapy; their reasons were recorded. Of 30 patients, all but one attained or maintained normal serum B12 levels. In many patients, the levels increased from baseline values, including 4 patients with short bowel syndrome. However, compliance with follow-up testing was fair, meaning that some patients had to be contacted and reminded to get their levels checked. For the one patient whose 3-month level was below normal, his dose was increased to 2 tablets daily, with a small improvement. High-dose oral B12 tablets should be the first choice for Crohn's patients with ileal resection and/or disease sufficient to produce vitamin B12 malabsorption. B12 injections should be reserved for those people who fail oral therapy, or who are reimbursed for injection therapy and cannot afford the cost of oral therapy.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.004 | 0.004 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".