Effects of zinc and multimineral vitamin supplementation on glycemic and lipid control in adult diabetes

AIMS To evaluate the effects of zinc with or without other antioxidants on blood glucose, lipid profile, and serum creatinine in adult diabetics on long-term follow-up. MATERIALS AND METHODS Patients (n = 96) were randomly allocated to three groups: group A (n = 29) was supplemented with oral zinc sulfate (22 mg/day) and multivitamin/mineral (zinc+MVM) preparation; group B (n = 31) was given the same preparation without zinc (MVM); and group C (n = 36) was given a matching placebo for a period of 4 months in a single-blinded study. Blood samples were taken at baseline and after 4 months of supplementation to assess blood glucose (fasting and postprandial) and glycosylated hemoglobin (Hb(A1C)%) and serum levels of zinc, creatinine, and lipids. RESULTS The zinc+MVM group had a mean change of fasting blood sugar -0.33 mmol/L (standard error of the mean 0.21 mmol/L) and was significant (P = 0.05) when compared with the other two groups (mean change in the MVM group +0.19 (0.31) mmol/L and +0.43 (0.23) mmol/L in the control group, respectively). The Hb(A1C)% level reduced significantly, irrespective of the baseline level, in zinc+MVM-supplemented individuals. In the other two groups, the change of Hb(A1C)% level was not significant. Serum lipid levels reduced significantly in the zinc+MVM and MVM groups. CONCLUSIONS Zinc+MVM supplementation showed beneficial effects in the metabolic control of adult diabetics in addition to elevating their serum zinc level. Zinc supplementation improved glycemic control measured by Hb(A1C)% and fasting and postprandial glucose. Furthermore, zinc supplementation lowered serum cholesterol and cholesterol/high-density lipoprotein ratio.