***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Acute renal failure is a serious complication in critically ill patients and frequently requires renal replacement therapy , which alters trace element and vitamin metabolism . OBJECTIVE The objective was to study trace element balances during continuous renal replacement therapy ( CRRT ) in intensive care patients . DESIGN In a prospect i ve r and omized crossover trial , patients with acute renal failure received CRRT with either sodium bicarbonate ( Bic ) or sodium lactate ( Lac ) as a buffering agent over 2 consecutive 24-h periods .  Copper , selenium , zinc , and thiamine were measured with highly sensitive analytic methods in plasma , replacement solutions , and effluent during 8-h periods . Balances were calculated as the difference between fluids administered and effluent losses and were compared with the recommended intakes ( RI ) from parenteral nutrition . RESULTS Nineteen sessions were conducted in 11 patients aged 65 + /- 10 y.  Baseline plasma concentrations of copper were normal , whereas those of selenium and zinc were below reference ranges ; glutathione peroxidase was in the lower range of normal . The replacement solutions contained no detectable copper , 0.01 micromol Se/L ( Bic and Lac ) , and 1.42 ( Bic ) and 0.85 ( Lac ) micromol Zn/L. Micronutrients were detectable in all effluents , and losses were stable in each patient ; no significant differences were found between the Bic and Lac groups . The 24-h balances were negative for selenium ( -0.97 micromol , or 2 times the daily RI ) , copper ( -6.54 micromol , or 0.3 times the daily RI ) , and thiamine ( -4.12 mg , or 1.5 times the RI ) and modestly positive for zinc ( 20.7 micromol , or 0.2 times the RI ) . CONCLUSIONS CRRT results in significant losses and negative balances of selenium , copper , and thiamine , which contribute to low plasma concentrations . Prolonged CRRT is likely to result in selenium and thiamine depletion despite supplementation at recommended amounts Background and Aims : Patients on maintenance hemodialysis ( HD ) face an increased risk of atherosclerosis , a crucial problem and the leading cause of cardiovascular morbidity and mortality . This study was design ed to evaluate the effects of zinc supplementation on paraoxonase ( PON ) enzyme activity in patients on HD . Methods : This double-blind r and omized controlled trial was conducted from June 2005 to June 2007 . Sixty HD patients were enrolled and divided into two groups : treatment ( case ) and control . The treatment and control groups were treated with 100 mg/day zinc or placebo , respectively , for 2 months . Serum zinc concentration was measured by atomic absorption spectrophotometry . PON activity  was evaluated by spectrophotometric method . Lipid profile  was determined using commercial kits , and apolipoprotein AI ( Apo-AI ) and B ( Apo-B ) levels were measured by commercial immunoturbidimetric kits . Results : In the case group , there was no significant change in the serum total cholesterol ( TC ) , triglyceride ( TG ) , low-density lipoprotein ( LDL ) , and Apo-B levels , while the serum levels of high-density lipoprotein ( HDL ) , Apo-AI , and PON activity were significantly increased ( p = 0.02 ) . In the control group , although significant increases were observed in the serum levels of TC , TG , and Apo-B ( p = 0.009 , 0.019 , and 0.001 , respectively ) , the serum PON activity was significantly decreased ( p = 0.025 ) and the serum levels of HDL , LDL , and Apo-AI were not changed . At the end of intervention period , the serum level of Apo-AI and PON activity were significantly higher in the case group . Conclusions : Zinc supplementation increased both the activity of PON and the serum level of Apo-AI in the HD patients Introduction Zinc is an essential trace element for human nutrition , and its deficiency is associated with anorexia , poor food efficiency , growth retardation , and impaired neurological and immune systems . The zinc-deficiency rate is particularly high in many disease states , such as with end-stage renal disease patients undertaking hemodialysis . The aim of this study was to determine the effect of zinc supplementation on body mass index ( BMI ) and serum levels of zinc and leptin in pediatric hemodialysis patients . Patients and methods This was a prospect i ve clinical trial study in which 60 hemodialysis patients were r and omly divided into two groups : group I received 50–100 mg zinc sulfate ( equivalent to 11–22 mg elemental zinc ) according to age , sex , and nutritional status of the child ; and group II received placebo ( cornstarch ) twice daily for 90 days . Anthropometric measurements were taken , and serum zinc and leptin levels were determined by colorimetric test with 5-Br-3′-phosphoadenosine-5′-phosphosulfate and enzyme-linked immunosorbent assay , respectively , at days 0 and 90 of the study . Results Zinc supplementation result ed in a significant increase in mean serum zinc level and BMI . Serum leptin decreased significantly after supplementation in children under hemodialysis . A significant negative correlation was observed between serum zinc and leptin levels as a result of zinc supplementation . Conclusion There was an increase in serum zinc level and BMI and decreased serum leptin  after zinc supplementation in children under hemodialysis Peroxidation of the membrane lipid structure of red blood cell leads to haemolysis and anaemia in haemodialysis patients . Dietary constituents of antioxidant vitamins and trace elements may play an important role in protecting against oxidant damage . In this study , the effects of supplementation of vitamin C and zinc on osmotic fragility and lipid peroxidation of erythrocytes were investigated in 34 zinc‐deficient haemodialysis patients . Sixteen sex‐ and age‐matched normal volunteers acted as controls . Patients were r and omized to receive vitamin C ( 250 mg day−1 ) , zinc ( 20 mg day−1 ) or a placebo treatment for 3 months . The levels of vitamin C , zinc , malondialdehyde ( MDA ) and osmotic fragility were measured initially and 3 months after supplementation . Mean serum concentration of vitamin C and zinc increased significantly in the groups at the end of the respective study periods . Supplementation with vitamin C and zinc improved osmotic fragility , and decreased the level of MDA in the groups , but some side‐effects ( i.e. nausea , vomiting , fever , muscle pain , weakness ) were observed during the zinc treatment . The results showed that the supplementation of both treatments decreased osmotic fragilty and MDA in zinc‐deficient haemodialysis patients . However , vitamin C treatment was found to be safer than zinc supplementation . Copyright © 2001 John Wiley & Sons , Background : In hemodialysis ( HD ) patients , zinc depletion caused by inadequate intake , malabsorption , and removal by HD treatment leads to erythropoiesis-stimulating agent ( ESA ) hyporesponsiveness . This study investigated the effects of zinc supplementation in HD patients with zinc deficiency on changes in the erythropoietin responsiveness index ( ERI ) . Methods : Patients on HD with low serum zinc levels ( < 65 μg/dL ) were r and omly assigned to two groups : The polaprezinc group ( who received daily polaprezinc , containing 34 mg/day of zinc ) ( n = 35 ) and the control group ( no supplementation ) ( n = 35 ) for 12 months . All the 70 patients had been taking epoetin alpha as treatment for renal anemia .  ERI was measured with the following equation : Weekly ESA dose (units)/dry weight (kg)/hemoglobin ( g/dL ) . Results : There were no significant changes in hemoglobin levels within groups or between the control and polaprezinc groups during the study period . Although reticulocyte counts were increased immediately after zinc supplementation , this change was transient . Serum zinc levels were significantly increased and serum copper levels were significantly decreased in the polaprezinc group after three months ; this persisted throughout the study period . Although there was no significant change in the serum iron or transferrin saturation levels in the polaprezinc group during the study period , serum ferritin levels significantly decreased following polaprezinc treatment . Further , in the polaprezinc  group , ESA dosage and ERI were significantly decreased at 10 months and nine months , respectively , as compared with the baseline value . Multiple stepwise regression analysis revealed that the change in the serum zinc level was an independent predictor of lowered ERI . Conclusions : Zinc supplementation  reduces ERI in patients undergoing HD and may be a novel therapeutic strategy for patients with renal anemia and low serum zinc levels Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more Increased homocysteine ( hCys ) level is an independent risk factor for cardiovascular complications in end-stage renal disease ( ESRD ) patients . The aim of this study was to evaluate effect of zinc ( Zn ) supplement on serum hCys level in ESRD patients . One hundred ESRD patients with Zn deficiency were enrolled in this double-blind r and omized clinical trial . They were r and omly subdivided into two groups and supplemented with Zn ( Zn group ) or placebo ( control group ) for 6 weeks . Fasting plasma hCys and Zn levels were measured before and at 43rd days after the start of the study . Serum Zn levels increased significantly ( p < 0.0001 ) , in Zn-treated group in comparison to placebo-treated group . In the Zn-treated group , serum hCys levels reduced significantly ( p < 0.0001 ) , compared to placebo group ( p > 0.05 ) . There was a significant ( p < 0.0001 ) reduction of mean percentage of hCys in Zn-treated group compared to the placebo group . Our study showed that Zn supplementation decreases serum hCys levels in ESRD patients with Zn deficiency OBJECTIVE To evaluate the intake and status of  antioxidants  in chronic kidney disease ( CKD ) patients . DESIGN R and omized control trial . SETTING Hospital outpatient department . SUBJECTS One hundred eighty-five subjects ( 145 predialysis CKD patients and 40 apparently healthy controls ) were enrolled for this study . The patients were divided into moderate and severe renal failure groups based on their creatinine and glomerular filtration rates . INTERVENTION All patients completed a food frequency question naire , 24-hour dietary recall form , and anthropometric measurements and underwent biochemical and antioxidant lab tests . MAIN OUTCOME MEASURES Dietary intake , anthropometry , biochemical measures of blood and antioxidant enzymes as well as oxidative stress . RESULTS Overall , the diet was significantly lower in antioxidant-rich food intake in all the CKD patients as compared with controls . The oxidative stress measured in blood was found to be in consonance with the intake from diet . CONCLUSION Micronutrients play a major role in the antioxidant status of the patients and must be monitored , as deficiency of these might elevate the oxidative stress of the body , especially in the chronic diseases The depression of the immune system in chronic uremia is a well-known phenomenon but the role of serum zinc ( Zn ) levels on both cell-mediated and humoral immunity is still controversial . The aim of this study was to investigate the effect of Zn supplementation on the immune system and on antibody response to  multivalent influenza vaccine ( MIV ) in hemodialysis patients ( HP ) . Twenty-six HP and 11 healthy subjects ( HS ) were vaccinated with MIV .  Hemodialysis patients were r and omly divided into two groups . Group 1 ( 13 HP ) was supplemented with 120 mg ZnS04 after each dialysis session . Group II ( 13 HP ) and Grouip III ( 11 HS ) were given placebo . In all cases , the serum Zn levels , CD3 , CD4 , CD8 , CD19 , HLA-DR+ cell percentages , CD4/CD8 ratio and CD3+HLA-DR+ cell percentages were determined before and 30 days after vaccination . Antibody levels to subgroups of MIV were also measured . All the baseline parameters studied were not statistically different between Group I and II . However , there was a significant difference between the basal parameters of Group III and the other two groups , except for CD3 and CD4 cell percentages . Serum Zn , CD19 cell percentage and antibody levels to MIV subgroups were significantly increased in Group I at the end of the first month of the study ( p<0.01 , p<0.05 , p<0.001 , p<0.001 , and p<0.01 , respectively ) , but the other parameters showed no significant changes . The only significant change observed in Groups II and III was an increase in antibody levels to MIV subgroups one month after vaccination . Antibody levels to MIV subgroups , were not statistically different between Groups I and II , but in Group III they were strikingly higher than those of HP ( p<0.001 ) 
    Output:
    
The results showed no differences in lipid profile .
Results of subgroup analysis supported the above results .
Our analysis shows that zinc supplementation may benefit the nutritional status of MHD patients and show a time-effect relationship