{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T20:40:34Z","timestamp":1788986434616,"version":"build-2803163510"},"reference-count":33,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T00:00:00Z","timestamp":1779062400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004606","name":"Chang Gung Memorial Hospital","doi-asserted-by":"publisher","award":["CMRPG 8C0621"],"award-info":[{"award-number":["CMRPG 8C0621"]}],"id":[{"id":"10.13039\/501100004606","id-type":"DOI","asserted-by":"publisher"}]},{"award":["CMRPG 8C0621"],"award-info":[{"award-number":["CMRPG 8C0621"]}],"id":[{"id":"https:\/\/ror.org\/02verss31","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background: Estrogen deficiency and glucocorticoid exposure are major contributors to osteoporosis. Although menaquinone-7 (MK-7) exhibits osteoprotective effects, whether low-dose supplementation is comparable to high-dose treatment remains unclear. Methods: Female Sprague\u2013Dawley rats were assigned to sham control (SC), ovariectomy plus dexamethasone (OVX+Dex), and OVX+Dex treated with low-dose MK-7 (100 \u03bcg\/kg) or high-dose MK-7 (20 mg\/kg). Bone microarchitecture, histopathology, and serum bone turnover markers were evaluated. Results: OVX+Dex induced marked deterioration of trabecular bone microarchitecture, characterized by reduced bone volume and structural disruption. These changes were accompanied by increased osteoclast activity (cathepsin K), decreased osteogenic and extracellular matrix\u2013related markers (cbfa-1, osteonectin, and biglycan), and downregulation of osteoprotegerin, indicating a pronounced imbalance in bone remodeling. Serum analysis further revealed reduced estradiol levels and alterations in circulating bone turnover markers, consistent with a dysregulated high-turnover state. Both low- and high-dose MK-7 significantly improved bone microarchitecture, restored remodeling-related protein expression, and partially normalized serum calcium-regulating hormones and bone turnover markers (all p &lt; 0.05), with no significant differences observed between doses. Conclusions: MK-7 attenuates osteoporosis by restoring the balance between bone resorption and formation. Notably, low-dose MK-7 provides protective effects comparable to high-dose treatment, supporting its potential clinical utility.<\/jats:p>","DOI":"10.3390\/nu18101605","type":"journal-article","created":{"date-parts":[[2026,5,18]],"date-time":"2026-05-18T14:40:31Z","timestamp":1779115231000},"page":"1605","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Comparable Protective Effects of Low- and High-Dose MK-7 on Bone Structure and Remodeling in a Rat Model of Osteoporosis Induced by Estrogen Deficiency and Glucocorticoid Exposure"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4201-6062","authenticated-orcid":false,"given":"Hsin-Ju","family":"Chiang","sequence":"first","affiliation":[{"name":"Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333323, Taiwan"},{"name":"AN-AN Women and Children Clinic, Kaohsiung 807038, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shu-Yuan","family":"Hsu","sequence":"additional","affiliation":[{"name":"Department of Anatomy, Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333323, Taiwan"},{"name":"Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833253, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1738-1028","authenticated-orcid":false,"given":"Steve","family":"Leu","sequence":"additional","affiliation":[{"name":"Institute for Translational Research in Biomedicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 833253, Taiwan"},{"name":"Department of Biotechnology, College of Life Science, Kaohsiung Medical University, Kaohsiung 807378, Taiwan"},{"name":"Department of Nutrition and Health Science, Fooyin University, Kaohsiung 831301, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Ozmen, S., Kurt, S., Timur, H.T., Yavuz, O., Kula, H., Demir, A.Y., and Balci, A. 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