Copper status in healthy Korean young men and its relation to their bone status

Objective: Several studies suggest an association between copper (Cu) deficiency and bone status in age-related osteoporosis; however, limited research exists on the Cu status including daily Cu intake in healthy populations. This study aimed to investigate the Cu nutritional status and to examine the potential role of Cu nutrition in the bone status of healthy young men. Materials and methods: A total of 359 healthy Korean adult males aged 19 - 28 participated in this study. The subjects were evaluated for anthropometric characteristics and nutrient intake using the 24-hour recall method. Bone mineral density (BMD) of calcaneus was measured using quantitative ultrasound. Serum Cu levels were analyzed using ICP-AES. Bone metabolism markers including blood total alkaline phosphatase, N-mid osteocalcin, and type 1 collagen C-terminal telopeptide concentrations were also analyzed. Results: Cu intake of the subjects was estimated as 1.3 +/- 0.4 mu g/day (156.8% of recommended intake). Major food sources of dietary Cu in the young Korean men were cereal and cereal products (40.0% of total Cu intake), meats and meat products (19.1%), eggs (6.8%), and nuts and seeds (6.7%). Cu intake correlated positively with intake of energy, protein, and calcium (p < 0.001, respectively). After adjusting for potential compounders of bone metabolism (age, weight, energy intake, protein intake, calcium intake, alcohol intake, smoking cigarettes, and regular exercise status), daily total Cu intake had no correlation with calcaneus BMD and the bone metabolism markers, but serum Cu levels had a positive correlation with serum total alkaline phosphatase activity, a bone formation marker (p < 0.01). Conclusion: These findings indicate that Cu intake status of the young Korean men meets the current recommended intake and in the young men whose Cu intake was sufficient, dietary Cu intake had no correlation with bone status and bone metabolism markers. However, there is a possible positive relationship between serum Cu levels and bone metabolism of young adult males. Further investigations in a large population with a wide range of Cu intake are needed.