The Association between Dietary and Circulating Copper Levels and Osteoporosis: a Scoping Review.

Copper plays a crucial role in osteoporosis by regulating osteoblast function, inhibiting osteoclast activity, and promoting bone matrix maturation. However, the epidemiological relationship between copper and osteoporosis remains inconclusive. This scoping review systematically examined the existing evidence on the association between dietary and circulating copper levels and bone related diseases with a special focus on osteoporosis. Studies were identified through comprehensive search of electronic databases from inception to January 2025. Eligible studies included randomized clinical trials, cohort studies, case-control studies, and cross-sectional studies involving human subjects and published in English. The review included 18 studies. For dietary copper, studies reported that higher intake was associated with improved bone mineral density (BMD). For circulating copper, studies reported that lower levels were associated with higher subsequent risk of osteoporosis and fractures. For environmental copper, exposed via drinking water or hair copper levels were not associated with osteoporosis. Current evidence on the relationship between copper and bone health remains largely consistent, suggesting a potential inverse association between copper levels and osteoporosis risk.