The effects of zinc supplementation on metabolic profile and oxidative stress in overweight/obese patients with non-alcoholic fatty liver disease: A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Evidence indicates the positive effects of zinc on insulin resistance and oxidative stress in metabolic syndrome or diabetes. Non-alcoholic fatty liver disease (NAFLD) is the main hepatic manifestation of insulin resistance and metabolic syndrome. The present study is the first clinical trial that evaluated the effects of zinc supplementation on metabolic and oxidative stress status in overweight/obese patients with NAFLD undergoing calorie- restriction diet. METHODS: Fifty six overweight/obese patients with confirmed mild to moderate NAFLD using ultrasonography were randomly allocated to receive 30 mg elemental zinc supplement (n = 29) or placebo (n = 27) along with weight loss diet for 12 weeks. Serum levels of zinc, homeostasis model of assessment-estimated insulin resistance (HOMA-IR), lipid profile, serum superoxide dismutas1 (SOD1) and malondialdhyde (MDA) levels were assessed. RESULTS: Serum levels of insulin, SOD1, MDA and HOMA-IR were improved in the treatment group (p < 0.05). Within group comparison showed significant reduction in serum FBS, HbA1C, TC, LDL-c and TG in the treatment group. CONCLUSION: Zinc supplementation for three months improved insulin resistance and oxidative stress status in overweight/obese NAFLD patients with no beneficial effects on lipid profiles over weight loss diet. Registration ID in IRCT (IRCT NO: 20181005041238N1).

The Effect of Zinc Supplementation on Steatosis Severity and Liver Function Enzymes in Overweight/Obese Patients with Mild to Moderate Non-alcoholic Fatty Liver Following Calorie-Restricted Diet: a Double-Blind, Randomized Placebo-Controlled Trial.

The role of zinc is known in balancing the oxidant/antioxidant system and also in improving insulin resistance in many diseases. Recently, in vivo and in vitro studies revealed roles of zinc on lipophagy and suppressing hepatic lipid deposition. The present study is the first double-blind randomized clinical trial that investigated the effect of zinc supplement on clinical manifestations and anthropometric parameters of overweight/obese non-alcoholic fatty liver patients following calorie-restricted diet. Fifty-six overweight/obese subjects with confirmed non-alcoholic fatty liver disease (NAFLD) using ultrasonography were randomized to treatment (calorie-restricted diet plus 30 mg/day zinc supplement) or placebo (calorie-restricted diet and placebo) groups. Serum liver enzymes and liver steatosis were measured at the baseline and 12 weeks post-intervention. Anthropometric measurements and food recalls were collected at the beginning, weeks 6 and 12. Zinc supplementation significantly elevated serum zinc concentrations in the treatment group (p < 0.001). Treatment also reduced alanine aminotransferase and γ-glutamyl transpeptidase enzymes in the treatment group (p < 0.05). Waist circumference was also significantly lowered in the zinc group (p < 0.05). Liver steatosis and fatty liver index changes were not significant between the groups. Overall, beneficial effects of zinc supplementation were shown on serum levels of zinc and liver enzymes in overweight/obese NAFLD patients.

Baseline levels determine magnitude of increment in 25 hydroxy vitamin D following vitamin D3 prescription in healthy subjects.

INTRODUCTION: Vitamin D deficiency is a major health problem which affects about one billion people in the world. Although, vitamin D supplementation is recommended as standard treatment of vitamin D deficiency, there are controversies on dose response relationship. In this regard, the present study aimed to determine the impact of vitamin D3 supplement on raising of serum 25 hydroxyvitamin D[25(OH)D] in healthy subjects with varying degrees of vitamin D deficiency. MATERIALS AND METHODS: In this clinical trial 114 subjects with varying degrees of vitamin D deficiency were entered and divided into three groups: serum levels of 25(OH) D less than 10 ng/ml, 10-20 ng/ml, and 20-30 ng/ml. All of the participants were given 50,000 units vitamin D3 per week for 8 weeks, thereafter, changes in serum levels of vitamin D and PTH were evaluated at week twelve. The results were analyzed using SPSS version 16 and P < 0.05 was considered to be significant. RESULTS: Of the 114 vitamin D deficient subjects, serum level of vitamin D was below 10 ng/ml in 22 persons (19.3%), 10-20 ng/ml in 52 persons (45.6%) and 20-30 ng/ml in 40 persons (35.1%). Following vitamin D prescription all people with varying degrees of vitamin D deficiency obtained a favorable serum level. The increase in vitamin D levels were 26.4, 18.5, and 8.3 ng/ml, in individuals with baseline vitamin D levels below 10 ng/ml, 10-20 ng/ml and 20-30 ng/ml, respectively. The changes in 25(OH) vitamin D in all three groups were significant (P < 0.05), nonetheless no significant alterations in serum levels of PTH were observed (P > 0.05). CONCLUSION: Our results indicated an inverse relationship between baseline serum levels of 25(OH) D and its increment following treatment with vitamin D3. Therefore, the magnitude of increments in serum 25(OH) D is greater in subjects with lower baseline levels of 25(OH) D.