Oral dosing of vitamins K1 and K2 in ovariectomized rats: Effects on bone loss and serum/bone levels
Bibliographic record
Abstract
Vitamin K (VK) exists in multiple forms that share common biochemical structures to support VK‐dependent protein carboxylation. Vitamin K may benefit bone by carboxylating the bone protein, osteocalcin. The unique side chains of the menaquinones (MKn) may further enhance K bone benefits. Despite plausible biological mechanisms, a causal role of vitamin K in bone and differential abilities of MKn and VK1 to benefit bone remains unclear. To assess this, ovariectomized (OVX) rats were randomized to 6 dosing groups of 16/group [Sham OVX (SOVX); OVX; OVX + Bisphosphonate (BP) (100ìg/kg/100 ìg/mL saline sc); OVX + VK1; OVX + MK4; and OVX + MK7] for 12 weeks. Equimolar doses of 107 mg K1/kg, 147 mg MK4/kg, and 201 mg/Kg MK7 were added to vitamin K deficient diets daily. As expected, OVX significantly increased weight and decreased bone strength vs. SOVX (p<0.05). OVX failed to significantly alter serum or bone vitamin K concentrations vs. SOVX. BP significantly increased bone strength and bone mineral density (BMD) vs. OVX (p<0.05). However, VK failed to prevent bone loss. VK1 supplementation significantly increased serum/bone concentrations of VK 1 vs. the concentrations of MK 4 or MK 7 following their supplementation (p<0.05). Unexpectedly, an MK7 epoxide was found in serum, not bone. Further studies evaluating the safety of MK 7 and potential efficacy of other doses of K vitamers are warranted. (Funding: Wyeth)
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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".