Vitamin D Works Best With Vitamin K for Fracture Healing – review

The role and therapeutic potential of vitamins in fracture healing

Nutrition Journal (BMC), 11 July 2026 (Article in Press), https://doi.org/10.1186/s12937-026-01360-4

Qingyuan Yu, Gongchang Yu, Huiqiang Dong, Chenyu Wang, Mengqi Guan, Bin Shi, Zhenhua Li - China

Summary by Claude - July, 2026

Up to 10% of fractures end in delayed or non-union, and this narrative review argues that vitamins — A, C, E, K, B and D — act as stage-specific modulators across the four phases of bone repair (

  • inflammation,
  • soft callus,
  • hard callus,
  • remodeling).

It is a mechanism-focused review, not a trial, so it pools no new outcome data; most claims rest on cell, animal, and observational studies.

For vitamin D specifically, the review positions it as a regulator of the entire healing process, not just calcium supply. Beyond 1,25(OH)₂D–VDR–RXR control of RUNX2, ALP, osteocalcin, RANKL and OPG, it highlights that the metabolite 24R,25(OH)₂D₃ appears to actively contribute to fracture repair rather than being an inert byproduct. Effects are dose- and stage-dependent: low doses stimulate precursor proliferation and early RUNX2, while higher doses may impair late-stage mineralization.

The most practically useful sections are on vitamin interactions. Vitamin D and K are synergistic — D drives osteocalcin/MGP expression, K carboxylates them so they can bind calcium; combined D3+K2 gave spinal-fusion rates of 86.1% at 3 months vs controls. Conversely, excess vitamin A suppresses 1,25(OH)₂D (via FGF23 and reduced 1α-hydroxylase) and high vitamin A:D ratios track with more fractures, and high-dose α-tocopherol can antagonize vitamin K. The authors' takeaway is "the right amount at the right stage, in the right combination," monitored with biomarkers (ucOC/total OC, MGP, Hcy, SAM/SAH).

"the effective application of vitamins in the context of fracture healing is not predicated on the notion that 'more is better'"

What this does not show / limitations:

No new clinical data and no systematic search or pooled effect sizes — it's a narrative synthesis, so it can't establish that supplementing any vitamin improves human fracture outcomes. Much of the mechanistic detail is from cell lines and rodents. Achieved 25(OH)D levels and specific fracture-healing doses are largely unspecified. It's an unedited accepted manuscript, and the reference list contains several citation mismatches, so specific claims should be verified against primary sources before use.PDF


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