A clinical trial investigating oral zinc supplementation in boys with Duchenne muscular dystrophy (DMD) found that treatment did not significantly improve key health measures.¹

Published in Nutrientsfocused the study on the role of zinc in muscle health and cellular function and aimed to assess changes in bioelectrical impedance parameters, which are indicators of muscle integrity, body composition and hydration. Despite its potential, zinc supplementation showed limited benefits, raising concerns about the appropriateness of current nutritional recommendations for patients with DMD.

The researchers found that nearly 30% of the 33 boys in the study, ages 5 to 24, had zinc levels below the healthy range at baseline, indicating a risk of zinc deficiency. After 4 months of supplementation, while zinc supplementation slightly reduced the proportion of boys with low zinc levels to 20%, the change was not statistically significant. There were also no statistically significant changes in muscle function or hydration measures such as phase angle (PA) and bioelectrical impedance vector analysis (BIVA), which monitor cellular health and body composition.

“DMD is a progressive neurodegenerative disease that induces permanent changes in muscle cell membranes,” the study authors said, noting the unique challenges of treating children with DMD. “Therefore, zinc supplementation may not be sufficient to change or improve the measured parameters.”

Muscle damage caused by DMD can limit zinc’s effectiveness. | Image credit: Celt Studio – stock.adobe.com

Zinc plays a critical role in maintaining cell membranes and supporting muscle function. But researchers found that muscle damage caused by DMD can limit zinc’s effectiveness. PA and BIVA results showed a decline in muscle health with age, and the study confirmed that these measures were not improved by zinc supplementation. The absence of changes in these parameters suggests that DMD’s progressive muscle deterioration requires more targeted interventions.

Zinc is an essential trace mineral required in small amounts but essential for nearly 100 enzymes that support critical body functions, including cell growth, DNA creation, tissue repair and immune function.² It plays a key role during periods of rapid growth, such as childhood, adolescence and pregnancy, when adequate zinc intake is essential for healthy development. The current recommended daily amount of zinc in adults is generally 11 mg per day for men and 8 mg for women, with an upper limit of 40 mg per day.³ The recommended dose ranges from 3 to 8 mg for children depending on age and 9 to 11 mg for teenagers.

“Given the inflammation and loss of lean mass in DMD, doses higher than those recommended for zinc are likely necessary to achieve an effect on the parameters measured,” the study authors said.¹

In addition to the limited effectiveness of zinc supplementation, the study also pointed to the utility of bioelectrical impedance measures such as PA and BIVA to monitor the health of patients with DMD. These tools can help track changes in body composition and detect worsening muscle loss, providing insights into disease progression and potential interventions.

The authors noted that future studies should include a more representative sample with a longer study period to determine the generalizability of these findings.

“Given the functions of zinc and the pathophysiology of DMD, it is important to implement strategies to prevent or treat zinc deficiency in this population,” the authors added. “Further studies investigating larger and safer doses of oral zinc supplementation are warranted.”

References

1. Vermeulen-Serpa KM, Lopes MMGD, Alves CX, et al. Effect of oral zinc supplementation on phase angle and bioelectrical impedance vector analysis in Duchenne muscular dystrophy: a non-randomized clinical trial. Nutrients. 2024;16(19):3299. doi:10.3390/nu16193299
2. Zinc. The source of nutrition. Updated March 2023. Accessed October 25, 2024. https://nutritionsource.hsph.harvard.edu/zinc/
3. Zinc. HHS. October 4, 2022. Accessed October 25, 2024.