The effect of zinc supplementation on glucose homeostasis: a randomised double-blind placebo-controlled trial

John R. Attia, Elizabeth Holliday, Natasha Weaver, Roseanne Peel, Kerry C. Fleming, Alexis Hure, John Wiggers, Mark McEvoy, Andrew Searles, Penny Reeves, Priyanga Ranasinghe, Ranil Jayawardena, Samir Samman, Judy Luu, Chris Rissel, Shamasunder Acharya

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)
6 Downloads (Pure)


Aims: The burden and health costs of Type 2 Diabetes Mellitus continue to increase globally and prevention strategies in at-risk people need to be explored. Previous work, in both animal models and humans, supports the role of zinc in improving glucose homeostasis. We, therefore, aimed to test the effectiveness of zinc supplementation on glycaemic control in pre-diabetic adults. Methods: We conducted a randomized, double-blind, placebo-controlled trial across 10 General Practitioner (GP) practices in NSW, Australia. The trial is known as Zinc in Preventing the Progression of pre-Diabetes (ZIPPeD)Study. Pre-diabetic (haemoglobin A1c [HbA1c] 5.7–6.4%, 39–46 mmol/mol) men and women (N = 98) were all assigned to a free state government telephone health coaching service (New South Wales Get Healthy Information and Coaching Service) and then randomised to either daily 30 mg zinc gluconate or placebo. Blood tests were collected at baseline, 1, 6 and 12 months for the primary outcomes (HbA1c, fasting blood glucose (FBG)); secondary outcomes included Homeostasis Model Assessment 2 (HOMA 2) parameters, lipids, body weight, height, waist circumference, blood pressure and pulse. Results: The baseline-adjusted mean group difference at 6 months, expressed as treatment–placebo, (95% CI) was −0.02 (−0.14, 0.11, p = 0.78) for HbA1c and 0.17 (−0.07, 0.42; p = 0.17) for FBG, neither of which were statistically significant. There were also no significant differences between groups in any of the secondary outcomes. Zinc was well tolerated, and compliance was high (88%). Conclusion: We believe our results are consistent with other Western clinical trial studies and do not support the use of supplemental zinc in populations with a Western diet. There may still be a role for supplemental zinc in the developing world where diets may be zinc deficient. Trial registration: Australian and New Zealand Clinical Trials Registry, ACTRN12618001120268. Registered on 6 July 2018.

Original languageEnglish
Pages (from-to)965-975
Number of pages11
Issue number7
Early online date22 Apr 2022
Publication statusPublished - Jul 2022
Externally publishedYes


  • Adults
  • Australia
  • Diabetes prevention
  • General practice
  • Get healthy
  • Prediabetes
  • Prevention
  • Randomized controlled trial
  • Zinc supplementation


Dive into the research topics of 'The effect of zinc supplementation on glucose homeostasis: a randomised double-blind placebo-controlled trial'. Together they form a unique fingerprint.

Cite this