The increase in prediabetes globally presents a major public health concern as individuals with prediabetes are at a higher risk of developing type 2 diabetes, highlighting the need for effective interventions. We present an intervention study protocol to evaluate the effects of daily supplementation with zinc, chromium, vitamin C, and copper (ZCC), combined with standard lifestyle interventions, on glucose profiles in prediabetic adults. We will conduct a randomized, double-blind, placebo-controlled trial over 12 months involving 670 prediabetic adults aged 35 to 64 in urban neighborhoods of Jakarta, Indonesia, with access to primary health centers or hospitals providing outpatient services. Participants will be divided into two groups: one will receive daily ZCC tablets (30 mg zinc, 50 μg chromium, 500 mg vitamin C, and 1 mg copper) alongside lifestyle interventions, while the other will receive an identical placebo with the same lifestyle intervention. Primary outcomes will include fasting blood glucose, a 2-h oral glucose tolerance test, hemoglobin A1c, and HOMA-IR levels, as well as the proportion of participants progressing to diabetes or becoming normal. Secondary outcomes will focus on lifestyle changes, lipid profiles, body weight and composition, and safety. Follow-up visits will be scheduled at 3, 6, and 12 months, with compliance monitored through returned tablet counts. This study aims to inform future nutritional interventions for diabetes prevention. TRIAL REGISTRATION: ClinicalTrials.gov ID NCT04511468. Registered on June 1st, 2020.