More than half of the magnesium found in the body is located in bone. In addition to its presence in bone, magnesium is important in calcium metabolism and bone health because it is required for parathyroid hormone secretion. Parathyroid hormone (PTH) is integral to bone health because it increases the production of the active form of vitamin D (1,25-dihydroxyvitamin D) and plays a role in the tubular reabsorption of calcium and phosphorus. Although magnesium deficiency is associated with abnormalities in vitamin D metabolism, hypocalcemia, and impaired PTH secretion, epidemiological studies linking magnesium intakes to measures of skeletal health have produced conflicting results. Some studies report significant associations between dietary magnesium intake and bone mineral density, but others have not supported this finding. Relationships between magnesium status and bone mass may be more challenging to elucidate due to the lack of a highly sensitive indicator of magnesium status. Studies have indicated that typical magnesium intakes in healthy adolescents may not be sufficient to maintain magnesium balance. Data on the impact of magnesium supplementation on bone mass remain controversial. While some studies have found magnesium supplementation to result in positive effects on bone mass, others have reported no significant benefit. Additional studies are needed to clarify these discrepancies and to assess the net effect of magnesium status and supplementation on bone metabolism. Because dietary intakes fall below recommended levels in several age groups and because of the known relationships between magnesium and hormones integral to bone health, increased attention should be focused on optimal magnesium intakes in relation to bone homeostasis. Zinc and copper play important roles in bone metabolism and bone health in part due to the roles they play as cofactors for various enzymes required for the synthesis or modification of bone matrix constituents. Zinc is a cofactor for a myriad of enzymes in the body, including alkaline phosphatase. Alkaline phosphatase is synthesized by osteoblasts and is essential for bone mineralization. Zinc also plays a role in the osteoblast via its involvement in aminoacyl-tRNA synthetase. Copper is a necessary cofactor for lysyl oxidase, an enzyme involved in collagen cross-linking. Both copper and zinc are found as components of superoxide dismutase, and they may protect bone from oxidative damage. Genetic defects that cause zinc deficiency (acrodermatitis enteropathica) or copper deficiency (Menkes' disease) result in growth retardation, stunting, and impaired bone growth. Although more research on the roles of zinc and copper in bone health and fracture risk is clearly needed, the importance of these nutrients in skeletal health should be recognized and optimal intakes should be promoted in relation to skeletal homeostasis.