Written by Alexa Heathorn, MS, CNS, Science Writer. Daily supplementation with 210 mg of zinc gluconate (30 mg elemental zinc) for 12 weeks improved hunger, desire to eat, prospective food consumption, and reduced pruritus in adults undergoing hemodialysis, without adverse effects or changes in body composition or muscle strength.

Chronic kidney disease (CKD) is characterized by impaired renal function, including the reduced excretion of nitrogenous waste products and dysregulation of electrolyte balance and blood pressure¹. CKD represents a significant global health burden, affecting approximately 10% of the world’s population¹. In advanced stages of the disease, dialysis becomes necessary to replace lost kidney function by removing excess fluid and metabolic waste from the body¹.

Hemodialysis (HD) is the most commonly used form of dialysis. While it is life-sustaining, HD is associated with a high burden of secondary complications. Among the most prevalent are malnutrition—affecting an estimated 30–70% of patients, and skin abnormalities such as xerosis (severe dry skin) and pruritus (persistent itchy skin), reported in up to 50–80% of individuals undergoing treatment¹.

Malnutrition in HD patients is closely linked to adverse changes in body composition, including muscle wasting, reduced lean mass, and increased fat mass¹. These alterations are strongly associated with declines in functional capacity, quality of life, and overall survival among individuals with end-stage kidney disease¹. Consequently, there is a need for supportive adjunctive therapies that can reduce the consequences of long-term hemodialysis, with the goal of improving patients quality of life and survival.

Zinc is an essential dietary trace element involved in numerous biochemical processes, including gene expression, protein synthesis, immune regulation, and neurological function¹. Zinc deficiency is highly prevalent among individuals undergoing hemodialysis, with estimates ranging from 40–80% of patients¹. This high burden of deficiency has led to growing interest in zinc repletion as a potential strategy to mitigate several complications associated with HD, including malnutrition and skin abnormalities¹.

Previous clinical studies have demonstrated that zinc supplementation can improve appetite in children with CKD, increase food intake in adults with CKD, and favorably influence body composition through its role in muscle growth and regeneration¹. In addition to its nutritional effects, zinc has been widely used in dermatologic care, with evidence supporting its role in the management of skin infections, inflammatory dermatoses, pigment disorders, and certain neoplasms¹.

Despite this supportive evidence, data specifically evaluating zinc supplementation in hemodialysis patients remain limited. Moreover, most prior studies have used zinc sulfate, a form associated with lower bioavailability and a higher incidence of gastrointestinal side effects¹. More absorbable forms of zinc, such as zinc gluconate, have not been adequately studied in this population¹. To address this gap, a parallel, double-blind, randomized clinical trial was conducted in 75 hemodialysis patients to evaluate the effects of zinc gluconate supplementation on malnutrition indices and skin abnormalities¹.

In this 12-week, parallel, double-blind randomized clinical trial, hemodialysis patients were randomly assigned to receive either one daily tablet of zinc gluconate (210 mg, providing 30 mg elemental zinc) or an identical placebo containing 30 mg of starch¹.

Participants in both groups were provided standardized dietary guidance, including avoidance of solid oils, fried foods, salty foods, high-fat dairy products, processed foods, and junk foods. They were also instructed to limit sugar-sweetened beverages and foods high in phosphorus¹.

Clinical assessments were conducted at baseline and at the end of the intervention period. Outcomes included measures of skin abnormalities (xerosis and pruritus), body composition, anthropometric variables, handgrip strength, and appetite¹.

The results of the 12-week study were as follows:

• Appetite outcomes
  • Zinc supplementation significantly improved:
    • Hunger (95% CI: 9.55 [3.67–15.42])
    • Desire to eat (95% CI: 7.03 [1.82–12.24])
    • Prospective food consumption (95% CI: 3.46 [0.30–14.10])
  • No significant effect was observed on fullness.
• Skin outcomes
  • Pruritus severity significantly decreased in the zinc group compared with placebo (95% CI: −0.52 [−0.82 to −0.22]), even after adjustment for baseline values.
  • Xerosis scores improved within both groups but did not differ significantly between zinc and placebo.
• Body composition & functional outcomes
  • No significant between-group differences were observed in:
    • Dry weight or BMI
    • Body fat, visceral fat, or muscle mass
    • Handgrip strength
  • Baseline body composition values were largely within normal ranges, limiting detectable change.

Potential limitations of the study include:

• The sample size was relatively modest (75 participants), which may limit the generalizability of the findings to the broader hemodialysis population.
• The study was conducted exclusively in Iranian adults, as all participants were recruited from dialysis centers in Iran; therefore, results may not be fully representative of patients in other geographic regions with different dietary patterns, healthcare systems, or genetic backgrounds.
• Participants were not severely malnourished at baseline, with most body composition and nutritional measures falling within normal ranges, which may have limited the ability to detect changes in muscle mass or strength.
• The intervention period was relatively short (12 weeks), making it unclear whether improvements in appetite and pruritus would be sustained over longer durations.
• Appetite outcomes were assessed using self-reported questionnaires, which may be influenced by individual perception and reporting bias.
• Serum zinc levels were not used to assess biological response or compliance, as zinc biomarkers are known to be unreliable in individuals with advanced kidney disease.

This study suggests that zinc gluconate supplementation may benefit people undergoing hemodialysis by improving appetite and reducing itching (pruritus), two common challenges in this population. While no changes in body composition or muscle strength were observed over 12 weeks, improved appetite may still support nutritional intake and quality of life. Zinc gluconate appears safe when used under clinical supervision, though longer-term studies are needed to assess sustained benefits and broader clinical outcomes.

Click here to read the full text study.

Posted January 29, 2026.

Alexa Heathorn, MS, CNS-c, is a clinical nutritionist specializing in metabolic health, hormonal balance, and gastrointestinal restoration through root-cause functional nutrition. She earned her master’s degree in Nutrition from Bastyr University and is currently a Certified Nutrition Specialist (CNS) candidate. Alexa also works as a research writer and functional health consultant, translating complex science into actionable strategies for practitioners and wellness companies. Learn more at www.bloomedwellness.com.

References:

1. Tavassoli M, Shahidi S, Askari G, Tavakoli N, Clark CCT, Rouhani MH. The Efficacy of Zinc Gluconate Supplementation in the Improvement of Malnutrition Indices and Skin Abnormalities in Hemodialysis Patients: A Randomized Clinical Trial. Int J Prev Med. 2024;15:63. doi:10.4103/ijpvm.ijpvm_206_23