Changes in Bone Parameters and Serum Zinc Levels Following Oral Zinc Supplementation in Duchenne Muscular Dystrophy: A Quasi-Experimental Study

Individuals with Duchenne muscular dystrophy (DMD) are prone to nutritional imbalances, and zinc deficiency may contribute to impaired bone health. This study evaluated serum zinc status and the effects of oral supplementation on bone parameters in DMD. In this quasi-experimental before-and-after study, 34 patients were assessed at three time points over eight months. Eligible participants who met the inclusion criteria and agreed to participate received the proposed interventions during routine follow-up at the Neurology outpatient clinic. Anthropometry, dietary intake, bone mineral density (BMD), bone mineral content (BMC), and serum zinc were measured; supplementation (5–15 mg/day) was provided for four months. Baseline zinc deficiency was observed in 36.7% of participants. No significant overall changes were detected. Stratified analyses revealed a modest increase in total body BMD among individuals with adequate baseline BMD (p = 0.02). As this finding emerged from a subgroup analysis, it should be interpreted cautiously, and the potential contribution of physiological growth to the observed change cannot be excluded. In addition, zinc-deficient participants showed a significant rise in serum zinc levels (p = 0.008). These findings suggest that the response to zinc supplementation may vary according to baseline nutritional and skeletal status and underscore the relevance of micronutrient monitoring in individuals with DMD. Trial registration: The trial was also registered in the Brazilian Registry of Clinical Trials under the code RBR-7cfdxm, approved on 14 June 2018.