Effect of vitamin K in bone metabolism and vascular calcification: A review of mechanisms of action and evidences.
Level 5 - mechanism / opinion, no new human data
Narrative review detailing biological mechanisms without systematic trial synthesis
PubMed 27437760 · doi:10.1080/10408398.2016.1211616
What was done
This was a narrative review examining the biological mechanisms and evidence regarding the actions of vitamin K, particularly vitamin K2 (menaquinone), on bone metabolism and vascular calcification.
What was found
No quantitative trial outcome numbers or effect estimates were reported in the abstract. Mechanistically, vitamin K2 stimulates bone formation by enhancing osteoblast differentiation, carboxylating osteocalcin, increasing alkaline phosphatase, IGF-1, GDF-15, and stanniocalcin 2, and decreasing Fas and Bax proteins. It decreases osteoclast differentiation by increasing osteoprotegerin and decreasing RANKL. In vessels, vitamin K2 inhibits hydroxyapatite formation through carboxylation of matrix Gla protein and Gla-rich protein, reduces vascular smooth muscle cell apoptosis via Gas6, and decreases vascular smooth muscle cell transdifferentiation into osteoblasts. A commonly cited human dosage is 45 mg/day.
Why it matters
It outlines the dual molecular pathways by which vitamin K2 simultaneously supports bone mineralization and prevents vascular calcification, particularly in post-menopausal osteoporosis.
Limits
The paper is a non-systematic narrative review providing mechanistic descriptions rather than empirical human outcome data. No quantitative effect sizes, clinical fracture reductions, or cardiovascular endpoints are reported in the abstract.
Cited by
- supports Without adequate vitamin K2, calcium is deposited in blood vessels and forms bone spurs rather than being incorporated into bones.