High-Dose Intramuscular Vitamin D Provides Long-Lasting Moderate Increases in Serum 25-Hydroxvitamin D Levels and Shorter-Term Changes in Plasma Calcium
Bibliographic record
Abstract
The best management of vitamin D deficiency, defined as a 25-hydroxyvitamin D [(25(OH)D] level <50 nM, is unclear. Intramuscular (IM) injection of a large bolus of vitamin D (≥100 000 IU) is used, but its safety is uncertain. In 10 adults given an IM injection of 600 000IU vitamin D3, we measured at baseline and at 1, 2, 3, and 4 weeks postinjection the serum levels of vitamin D3, 25(OH)D3, 25(OH)D2, total 25(OH)D, 3-epi-25(OH)D3, and 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] using a standardized LC with tandem MS (MS/MS) assay; serum levels of 25(OH)D using the Abbott ARCHITECT i2000 immunoassay; and markers of bone metabolism. Bone markers and 25(OH)D (immunoassay) were remeasured at 24 weeks. All participants had baseline total 25(OH)D levels >50 nM. Serum 25(OH)D levels increased at 3, 4, and 24 weeks postinjection, peaking at 4 weeks [mean ± SEM of 126 ± 7.9 nM (immunoassay) and 100 ± 5.5 nM (LC-MS/MS)] but generally remained <125 nM, the upper limit recommended by the U.S. Institute of Medicine. Serum 24,25(OH)2D3 levels increased at 3 and 4 weeks postinjection. Serum ionized calcium levels were higher than baseline at 1, 3, and 4 weeks postinjection but remained within the clinically normal range. Other biochemical parameters, including other vitamin D metabolites, plasma alkaline phosphatase, and parathyroid hormone levels, were unchanged. IM injection of a large bolus of vitamin D effectively increases serum 25(OH)D levels without evidence of metabolic abnormality.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".