The influence of habitual salt intake on bone remodelling in young healthy people

Introduction: Sodium alters calcium metabolism by increasing calcium excretion, thus possibly influencing bone metabolism. The hypothesis of the present study is that amount of dietary sodium intake affects the bone remodelling. This study aimed to assess whether a habitual intake of sodium has an effect on peak bone mass and biochemical indicators of bone metabolism. Subjects and Methods: In a cross-sectional study that involved 41 young men and women, six biochemical markers were assessed from blood samples using ELISA: osteocalcin, C-terminal procollagen type I peptide, receptor activator kappa B ligand, pyridinoline, parathyroid hormone, and osteoprotegerin, while bone mineral density (BMD) and bone mineral content (BMC) were measured by dual x-ray absorptiometry. Subjects were divided into two groups according to habitual sodium intake (low-Na and high-Na group) assessed by questionnaire. Results: No difference was found between groups of low and high Na intake in BMD and BMC, or in biochemical markers of bone metabolism. Since the groups differed in Ca intake, energy and vitamin D, adjustments were made for those cofounders. Regression analysis showed that only the dietary intake of vitamin D was associated with dual femur BMD and BMC, and no correlation was found between bone remodelling indicators and Na intake after adjustment for vitamin D intake. Conclusion: The present results could not confirm that habitual sodium intake above recommended levels affects bone remodelling processes or decreases bone mineral density in young healthy people if combined with adequate calcium intake.