Nutrients, Nutraceuticals, and Bone

Background. Nutrients and nutraceuticals are widely used as supplements for osteoporosis prevention or as adjunctive therapy, but the evidence from human studies is inconsistent. Objective. To review data on micro-and macronutrients and nutraceuticals that influence bone mineral density (BMD), turnover, microarchitecture, or fracture risk, contextualizing findings within guidelines. Methods. Narrative review of randomized controlled trials (RCTs), meta-analyses, and extensive observational studies published through August 19, 2025. Outcomes prioritized include BMD, fractures, bone turnover markers (BTMs), and indices of bone quality such as trabecular bone score (TBS). Results and discussion. Substantial evidence supports correcting low calcium (Ca) intake and reduced vitamin D levels, the only supplements consistently endorsed by guidelines for osteoporosis management. Moderate evidence includes collagen peptides, vitamin K2 (MK-7), with site-specific but mixed results; alkali salts improve turnover and BMD, resveratrol shows small gains, and prebiotics enhance Ca absorption. There is weak evidence available for omega-3 fatty acids, isoflavones, green tea catechins, prunes, hesperidin, probiotics, minerals, and silicon. Main botanicals and carotenoids remain experimental. Safety profiles vary across compounds, and long-term safety data are insufficient for most nutraceuticals. Conclusions. Nutrients and nutraceuticals can complement lifestyle and pharmacotherapy when tailored to address specific deficiencies or phenotypes. Large, long-term RCTs with safety, fracture outcomes, and microarchitectural endpoints are needed to clarify efficacy and guide evidence-based recommendations.