Effects of zinc supplementation on lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: Findings on the effects of zinc supplementation on the lipid profile in patients with type 2 diabetes mellitus (T2DM) are conflicting. The current comprehensive systematic review and meta-analysis aimed to summarize available evidence in this regard. METHODS AND RESULTS: After a systematic search in the online databases, we included the randomized controlled trials (RCTs) investigating the effect of zinc supplementation on lipid profile [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG)] in patients with T2DM. Altogether, 9 studies with a total sample size of 424 patients with T2DM were included in the analysis. Combining 9 effect sizes from 9 RCTs, we found a significant lowering effect of zinc supplementation on serum levels of TG (weighted mean difference (WMD): -17.08, 95% CI: -30.59, -3.58 mg/dL, P = 0.01) and TC (WMD: -26.16, 95% CI: -49.69, -2.62 mg/dL, P = 0.02). Although the overall effect of zinc supplementation on LDL-C levels was not significant, a beneficial effect was seen in studies that administered <100 mg/d zinc. Based on the non-linear dose-response analysis, a greater reduction in serum levels of TC and LDL-C following zinc supplementation was seen at <12 weeks' duration of intervention. Unlike the overall effect size, we found a significant increasing effect of zinc supplementation on serum HDL-C concentrations in most subgroups of RCTs according to the subgroup analyses. CONCLUSION: We found that zinc supplementation may beneficially influence lipid profile in patients with T2DM.

Zinc for Infection Prevention in Sickle Cell Anemia (ZIPS): study protocol for a randomized placebo-controlled trial in Ugandan children with sickle cell anemia.

BACKGROUND: Sickle cell anemia (SCA) is the most common inherited hemoglobinopathy worldwide. Infection is a major cause of illness and death in children with SCA, especially in sub-Saharan Africa where an estimated 50-90% of affected children die before their fifth birthday. Interventions to reduce the incidence and severity of infections are needed urgently. A high proportion of adults and children with SCA are zinc-deficient, and zinc deficiency leads to impaired immunity and an increased risk of infection. Zinc supplementation has been shown to decrease the risk of infection in adolescents and adults, but there are no data on the effectiveness of zinc for prevention of infection in children < 5 years of age with SCA. METHODS/DESIGN: The study will be a randomized, placebo-controlled, double-blind clinical trial in which 250 Ugandan children 1.00-4.99 years of age with SCA will receive daily zinc supplementation (10 mg oral dispersible tablet) or identical placebo for 12 months. DISCUSSION: If this trial shows a reduction in severe or invasive infection incidence, it would be the basis for a multi-site, multi-country clinical trial to assess real-world safety and efficacy of zinc in African children with SCA. Since zinc is safe, inexpensive, and easy to administer, this trial has the potential to improve the health of hundreds of thousands of African children with SCA through reduction of infection-related morbidity and mortality. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03528434. Registered on May 17, 2018 Protocol Version: 1.0. Date: Dec 11, 2017 Sponsor: Indiana University. Sponsor's protocol identifier, 1712339562.

The influence of zinc sulfate on neonatal jaundice: a systematic review and meta-analysis.

INTRODUCTION: Zinc sulfate may be a promising approach to treat neonatal jaundice. However, the results remain controversial. We conducted a systematic review and meta-analysis to evaluate the efficacy and safety of zinc sulfate on hyperbilirubinemia among neonates. METHODS: PubMed, EMbase, Web of science, EBSCO, Cochrane library databases, Ovid, BMJ database, and CINAHL were systematically searched. Randomized controlled trials (RCTs) assessing the effect of zinc sulfate versus placebo on the prevention of jaundice in neonates were included. Two investigators independently searched articles, extracted data, and assessed the quality of included studies. The primary outcomes were total serum bilirubin (TSB) on three days and seven days, the incidence of hyperbilirubinemia. Meta-analysis was performed using random- or fixed-effect models. RESULTS: Five RCTs involving 645 patients were included in the meta-analysis. Overall, compared with placebo, zinc sulfate supplementation failed to significantly reduce TSB on three days (mean difference (MD) = 0.09 mg/dL; 95% confidence interval (CI) = -0.49 to 0.67; p = .77), TSB on seven days (MD = -0.37 mg/dL; 95% CI = -98 to 0.25; p = .25) as well as the incidence of hyperbilirubinemia (OR = 1.14; 95% CI = 0.74 to 1.76; p = .56). Zinc sulfate showed no influence on phototherapy requirement (OR = 0.90; 95% CI = 0.41 to 1.98; p = .79), but resulted in significantly decreased duration of phototherapy (MD = -16.69 h; 95% CI = -25.09 to -8.3 h; p < .0001). CONCLUSIONS: Zinc sulfate could not reduce the TSB on three days and seven days, the incidence of hyperbilirubinemia and phototherapy requirement, but lead to significantly decreased duration of phototherapy.

Zinc Supplementation in Treatment of Children With Urinary Tract Infection.

INTRODUCTION: Urinary tract infection (UTI) is very common in children. Precocious diagnosis and appropriate treatment are important because of the permanent disease complications. Zinc increases the response to treatment in many infections. In this study, we explored the effect of zinc in treating UTI. MATERIALS AND METHODS: Two hundred children with UTI were divided into 2 groups of 100 who were comparable in terms of age, sex, urine laboratory profiles, and clinical signs and symptoms. The control group received a standard treatment protocol for UTI and the intervention group received oral zinc sulfate syrup plus routine treatment of UTI. RESULTS: A faster recovery was observed in the patients receiving zinc, but abdominal pain was exacerbated by zinc and lasted longer. Three months after the treatment, there was no significant difference between the two groups in the time of fever stop and negative urine culture. CONCLUSIONS: In children with UTI, zinc supplementation has a positive effect in ameliorating severe dysuria and urinary frequency while the use of this medication is not recommended in the presence of abdominal pain.

Efficacy of zinc sulphate on in-hospital outcome of community-acquired pneumonia in people aged 50 years and over.

SETTING: Some studies have reported a beneficial effect of zinc sulphate in children with community-acquired pneumonia (CAP). OBJECTIVE: To evaluate the effect of adjuvant zinc therapy in adult hospitalised CAP patients aged ⩾50 years on standard antibiotic treatment. METHODS: In a randomised double-blind placebo-controlled clinical trial, 91 hospitalised patients diagnosed with CAP using standard clinical and radiological criteria were randomised to receive 220 mg (110 mg twice daily) zinc sulphate for 4 days or placebo, in addition to antibiotics. The primary endpoint was length of hospital stay, and secondary endpoints were time to normalisation of oxygen saturation, respiratory rate and temperature. Disease severity was scored using CURB-65 (mental Confusion, Urea >20 mg/dl, Respiratory rate ⩾30/min, low Blood pressure and age ⩾65 years) RESULTS: The results did not show significant differences in length of hospital stay, time to normalisation of respiratory rate and oxygen saturation between patients in the zinc sulphate and placebo groups (P = 0.18, 0.65 and 0.26, respectively). CONCLUSION: A short course of zinc supplementation does not improve outcome in hospitalised patients aged ⩾50 years with CAP. In this setting, it should not be recommended as routine adjunctive treatment.

Efficacy of zinc sulfate supplement on febrile seizure recurrence prevention in children with normal serum zinc level: A randomised clinical trial.

OBJECTIVE: Serum zinc level might be related to pathogenesis of febrile seizure (FS). The purpose of this study was to evaluate efficacy and safety of oral zinc supplementation on FS recurrence prevention in non-zinc-deficient children. MATERIALS AND METHODS: In a randomized clinical study, one hundred 18 to 60 mo old children with normal zinc level with first simple FS were referred to Shahid Sadoughi Hospital, Yazd, Iran from May 2012 to June 2013, were randomly assigned to two groups to receive 2 mg/kg/d zinc sulfate for six consecutive months or placebo as control group and were followed up for 1 y for FS recurrence. RESULTS: 41 girls and 59 boys with mean age of 2.47 ± 1.01 y were evaluated. Race, mean weight, height and body fat were similar in both groups. FS recurrence occurred in 19 children (38%) in the control group [95% confidence interval (CI): 19.45%-53.95%] and in 11 children (22%) in the zinc sulfate (95% CI: 57.47%-89.13%) groups, respectively; and the zinc group had lower FS recurrence (P = 0.03). The mean serum zinc level before intervention was lower in children with FS recurrence (72.43 ± 14.58 µg/dL versus 96.33 ± 12.69 µg/dL, P = 0.04). Gastrointestinal side effects (vomiting in five children, heartburn in two children and abdominal pain in one child) were seen in 16% of the zinc group and vomiting occurred in two children (4%) in control group and frequency of adverse events was similar in the two groups (P = 0.1). CONCLUSION: Zinc supplementation should be considered as effective and safe in prevention of FS recurrence.

Effects of zinc sulfate supplementation on cell-mediated immune response in head and neck cancer patients treated with radiation therapy.

Zinc deficiency is an important factor that impairs cellular immunity and contributes to low T lymphocyte counts in head and neck cancers. Persistent T lymphopenia is clinically relevant in terms of tumor persistence and/or recurrence. The primary objective was to evaluate the impact of zinc sulfate supplementation on the absolute numbers of circulating T lymphocytes and T lymphocyte subpopulations. The secondary objectives were to evaluate overall survival, progression-free survival, and the adverse events of zinc sulfate. Seventy-two head and neck cancer patients were enrolled in a randomized, double-blind, placebo-controlled trial. Zinc sulfate 50 mg in 10 cc and an identically appearing placebo were self-administered 3 times daily at meal times. Blood samples were obtained for complete blood count, total T lymphocytes and T lymphocyte subpopulations before radiation therapy as baselines, at the fifth week during radiation therapy, and at the first month after completion of radiation therapy. The baseline characteristics of patients, tumors, and treatments and the baseline lymphocyte parameters were not significantly different between the 2 groups. Zinc sulfate supplementation during head and neck radiation therapy showed no increase in absolute numbers of circulating T lymphocytes, T lymphocyte subpopulations, or survival with acceptable side effects.

Nasal carriage of mecA-positive methicillin-resistant Staphylococcus aureus in pigs exhibits dose-response to zinc supplementation.

Zinc (Zn) is often supplemented at elevated concentrations in swine diets, particularly in piglets, to prevent enteric infections and promote growth. Previous studies from Denmark have suggested a genetic linkage and a phenotypic association between Zn resistance, encoded by czrC, and methicillin-resistance conferred by mecA in Staphylococcus aureus. Such an association has not been reported in the U.S. swine population. We conducted an analysis of the effects of Zn, supplemented as zinc oxide (ZnO), on the nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) in nursery (n=40) and finisher pigs (n=40) enrolled in a nutritional study. Nasal swabs, collected from nursery and finisher pigs, were inoculated onto MRSA CHROMagar and presumptive MRSA colonies were tested for the presence of mecA and czrC genes by polymerase chain reaction. Zinc susceptibility was determined by the agar dilution method. The prevalence of mecA-positive MRSA was 10% (4/40) and 20% (8/40) among nursery and finisher pigs, respectively. Of the 12 mecA-positive S. aureus isolates, 7 had the czrC gene (58.3%) compared to none among the 68 mecA-negative isolates. The presence of both mecA (p=0.002) and czrC (p=0.006) genes were positively associated with higher levels of Zn supplementation. The median minimum inhibitory concentrations of Zn for czrC-positive and czrC-negative isolates were 12 and 2 mM, respectively (p<0.0001). The link between czrC and mecA genes suggests the importance of elevated Zn supplementation in the co-selection and propagation of methicillin resistance among S. aureus in pigs.

Efficacy of combination therapy of oral zinc sulfate with imiquimod, podophyllin or cryotherapy in the treatment of vulvar warts.

AIM: Zinc sulfate is beneficial in the treatment of epithelial warts. We conducted this study to compare the efficacy of combination therapy of oral zinc sulfate with conventional treatments in the treatment of vulvar warts. MATERIAL AND METHODS: This study was a randomized controlled trial. The sample size was 42 in each group. Women aged 20-50 years were placed by the block randomized method into six groups: the podophyllin-, imiquimod- and cryotherapy-treated groups, and another three groups receiving 8-week combination therapy of 400 mg oral zinc sulfate with one of the above-mentioned treatments. Data were analyzed using anova and Fischer's exact test with spss16. RESULTS: A total of 228 patients were recruited and completed the study in six treatment groups. No significant difference was observed in the response to treatment among these groups. Relapse after 6 months was significantly higher in the podophyllin-, imiquimod- and cryotherapy-treated patients compared to patients receiving these treatments in combination with oral zinc sulfate (P<0.05). CONCLUSIONS: Combined therapy of oral zinc sulfate with conventional treatments of vulvar warts appears to reduce the relapse rate.

Zinc for the common cold.

BACKGROUND: The common cold is one of the most widespread illnesses and is a leading cause of visits to the doctor and absenteeism from school and work. Trials conducted in high-income countries since 1984 investigating the role of zinc for the common cold symptoms have had mixed results. Inadequate treatment masking and reduced bioavailability of zinc from some formulations have been cited as influencing results. OBJECTIVES: To assess whether zinc (irrespective of the zinc salt or formulation used) is efficacious in reducing the incidence, severity and duration of common cold symptoms. In addition, we aimed to identify potential sources of heterogeneity in results obtained and to assess their clinical significance. SEARCH METHODS: In this updated review, we searched CENTRAL (2012, Issue 12), MEDLINE (1966 to January week 2, 2013), EMBASE (1974 to January 2013), CINAHL (1981 to January 2013), Web of Science (1985 to January 2013), LILACS (1982 to January 2013), WHO ICTRP and clinicaltrials.gov. SELECTION CRITERIA: Randomised, double-blind, placebo-controlled trials using zinc for at least five consecutive days to treat, or for at least five months to prevent the common cold. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed trial quality. MAIN RESULTS: Five trials were identified in the updated searches in January 2013 and two of them did not meet our inclusion criteria. We included 16 therapeutic trials (1387 participants) and two preventive trials (394 participants). Intake of zinc was associated with a significant reduction in the duration (days) (mean difference (MD) -1.03, 95% confidence interval (CI) -1.72 to -0.34) (P = 0.003) (I(2) statistic = 89%) but not the severity of common cold symptoms (MD -1.06, 95% CI -2.36 to 0.23) (P = 0.11) (I(2) statistic = 84%). The proportion of participants who were symptomatic after seven days of treatment was significantly smaller (odds ratio (OR) 0.45, 95% CI 0.20 to 1.00) (P = 0.05) than those in the control, (I(2 )statistic = 75%). The incidence rate ratio (IRR) of developing a cold (IRR 0.64, 95% CI 0.47 to 0.88) (P = 0.006) (I(2) statistic = 88%), school absence (P = 0.0003) and prescription of antibiotics (P < 0.00001) was lower in the zinc group. Overall adverse events (OR 1.58, 95% CI 1.19 to 2.09) (P = 0.002), bad taste (OR 2.31, 95% CI 1.71 to 3.11) (P < 0.00001) and nausea (OR 2.15, 95% CI 1.44 to 3.23) (P = 0.002) were higher in the zinc group. The very high heterogeneity means that the averaged estimates must be viewed with caution. AUTHORS' CONCLUSIONS: Zinc administered within 24 hours of onset of symptoms reduces the duration of common cold symptoms in healthy people but some caution is needed due to the heterogeneity of the data. As the zinc lozenges formulation has been widely studied and there is a significant reduction in the duration of cold at a dose of ≥ 75 mg/day, for those considering using zinc it would be best to use it at this dose throughout the cold. Regarding prophylactic zinc supplementation, currently no firm recommendation can be made because of insufficient data. When using zinc lozenges (not as syrup or tablets) the likely benefit has to be balanced against side effects, notably a bad taste and nausea.

Short-course prophylactic zinc supplementation for diarrhea morbidity in infants of 6 to 11 months.

BACKGROUND: Zinc supplementation during diarrhea substantially reduces the incidence and severity of diarrhea. However, the effect of short-course zinc prophylaxis has been observed only in children >12 months of age. Because the incidence of diarrhea is comparatively high in children aged 6 to 11 months, we assessed the prophylactic effect of zinc on incidence and duration of diarrhea in this age group. METHODS: In this randomized, double-blind, placebo-controlled trial, we enrolled infants aged 6 to 11 months from an urban resettlement colony in Delhi, India, between January 1, 2011, and January 15, 2012. We randomly assigned 272 infants to receive either 20 mg of zinc or a placebo suspension orally every day for 2 weeks. The primary outcome was the incidence of diarrhea per child-year. All analyses were done by intention-to-treat. RESULTS: A total of 134 infants in the zinc and 124 in the placebo groups were assessed for the incidence of diarrhea. There was a 39% reduction (crude incident rate ratio [IRR] 0.61, 95% confidence interval [CI] 0.53-0.71) in episodes of diarrhea, 39% (adjusted IRR 0.61, 95% CI 0.54-0.69) in the total number of days that a child suffered from diarrhea, and reduction of 36% in duration per episode of diarrhea (IRR 0.64, 95% CI 0.56-0.74) during the 5 months of follow-up. CONCLUSIONS: Short-course prophylactic zinc supplementation for 2 weeks may reduce diarrhea morbidity in infants of 6 to 11 months for up to 5 months, in populations with high prevalence of wasting and stunting.

Antioxidant and antitumor activities of selenium- and zinc-enriched oyster mushroom in mice.

Selenium and zinc are well-known essential trace elements with potent biological functions. However, the possible health benefits of the combined administration of dietary selenium and zinc have not been studied extensively. In this study, we prepared selenium- and zinc-enriched mushrooms (SZMs) containing increased levels of selenium and zinc. The effects of SZMs on antioxidant and antitumor activities were evaluated. Mice were fed with either a control diet or a diet supplemented with SZMs or sodium selenite and zinc sulfate for 6 weeks. Antioxidant capacity was investigated by measuring the activities of antioxidant enzymes and the levels of lipid peroxide products. Results showed that treatment with SZMs significantly increased the activities of glutathione peroxidase (GPx) and superoxide dismutase and decreased the levels of malondialdehyde and lipofuscin. Furthermore, using a mouse model of lung tumors, we found that SZMs significantly decreased the number of tumor nodes with an increase in the activity of GPx. SZMs had a greater effect on the increase in both antioxidant and antitumor activities than did sodium selenite and zinc sulfate. These findings suggest that SZMs may be effective for improving antioxidant capacity and preventing tumors.

Long term excessive Zn-supplementation promotes metabolic syndrome-X in Wistar rats fed sucrose and fat rich semisynthetic diet.

During the last two decades Zinc (Zn) as a micronutrient is being used indiscriminately in agricultural and husbandry practices and also in baby foods and multivitamin supplements with a view that Zn is non-toxic and promotes linear growth and body weight in the consumers. The long-term effect of increasing Zn load in the body has not been worked out so far. In this study, three groups of rats were fed on a semi-synthetic diet containing 20 mg (control, group-I), 40 mg (group-II) and 80 mg Zn /kg (group-III) diet respectively for 6 months. The results revealed that the gain in body weight increased in rats in Zn-concentration dependent manner. The urine examined on weekly basis showed glucosuria in group-II on week 10 and in group-III on week 8 and thereafter. The arterial blood pressure was significantly higher in group-II and III than their control counter parts on monthly basis. Histochemical examination of skin revealed an increase in the number of adipocytes filled with triglycerides making a subcutaneous fatty tissue thicker in group-II and group-III than that of control group. The blood profile after 180 days of dietary treatment, displayed a significant rise in glucose, total lipids, cholesterol, triglycerides, LDL-cholesterol, VLDL-cholesterol, insulin, cortisol and aldosterone whereas HDL-cholesterol, T3, T4 and TSH showed a reduction in their levels in the blood serum. The tissue metal status showed an increase of Zn, Cu and Mg in the serum, a rise in Zn in liver, hair and abdominal muscles and fall in Cu and Mg concentrations in liver, hair and abdominal muscles. This data suggest that Zn in excess in diet when fed for longer periods of time induces metabolic syndrome-X.

Oral zinc sulphate causes murine hair hypopigmentation and is a potent inhibitor of eumelanogenesis in vivo.

BACKGROUND: C57BL/6 a/a mice have been widely used to study melanogenesis, including in electron paramagnetic resonance (EPR) studies. Zinc cations modulate melanogenesis, but the net effect of Zn2+ in vivo is unclear, as the reported effects of Zn2+ on melanogenesis are ambiguous: zinc inhibits tyrosinase and glutathione reductase in vitro, but also enhances the activity of dopachrome tautomerase (tyrosinase-related protein-2) and has agonistic effects on melanocortin receptor signalling. OBJECTIVES: To determine in a C57BL/6 a/a murine pilot study whether excess zinc ions inhibit, enhance or in any other way alter hair follicle melanogenesis in vivo, and to test the usefulness of EPR for this study. METHODS: ZnSO(4).7H2O was continuously administered orally to C57BL/6 a/a mice during spontaneous and depilation-induced hair follicle cycling (20 mg mL-1; in drinking water; mean+/-SD daily dose 1.2+/-0.53 mL), and hair pigmentation was examined macroscopically, by routine histology and by EPR. RESULTS: Oral zinc cations induced a bright brown lightening of new hair shafts produced during anagen, but without inducing an EPR-detectable switch from eumelanogenesis to phaeomelanogenesis. The total content of melanin in the skin and hair shafts during the subsequent telogen phase, i.e. after completion of a full hair cycle, was significantly reduced in Zn-treated mice (P=0.0005). Compared with controls, melanin granules in precortical hair matrix keratinocytes, hair bulb melanocytes and hair shafts of zinc-treated animals were reduced and poorly pigmented. Over the course of several hair cycles, lasting hair shaft depigmentation was seen during long-term exposure to high-dose oral Zn2+. CONCLUSIONS: High-dose oral Zn2+ is a potent downregulator of eumelanin content in murine hair shafts in vivo. The C57BL/6 mouse model offers an excellent tool for further dissecting the as yet unclear underlying molecular basis of this phenomenon, while EPR technology is well suited for the rapid, qualitative and quantitative monitoring of hair pigmentation changes.

Effects of dietary zinc supplementation on hen performance, ammonia volatilization, and nitrogen retention in manure.

This investigation was undertaken to evaluate the effects of dietary ZnSO4 supplementation on ammonia volatilization and nitrogen retention in hen manure. One hundred twenty, 45-wk-old commercial Leghorn laying hens were sequentially fed diets with 1000, 2000, and 3000 ppm Zn as ZnSO4 (Zn-1000, Zn-2000, and Zn-3000), then followed by two control dietary periods with 114 ppm Zn (Control-1 and Control-2) for a total of five consecutive eight-day experiment periods, respectively. When hens were fed the 1000 and 2000 ppm Zn treatment diets, room ammonia levels were significantly reduced compared to the control diets. Dietary Zn treatments reduced the decomposition of uric acid, resulting in an increase in manure total-N retention compared to the control fed birds. The 1000 ppm Zn supplement had no adverse effects on hen body weight, feed consumption, egg production, egg weight, albumen height, or shell thickness. However, hens fed the diet containing 3000 ppm Zn had significantly depressed body weight, feed consumption, egg production, egg weight, and shell thickness. Zinc levels of egg contents increased linearly as dietary Zn levels increased. These levels in eggs would not be a problem for human consumption because these are much less than the daily Zn recommended dietary allowance. Although land application of such manure will not cause environmental problems or crop toxicity, proper monitoring of soil and crop Zn levels and effective nutrient management planning would be well advised.

Effects of dietary zinc supplementation on broiler performance and nitrogen loss from manure.

An experiment was conducted to evaluate the effects of ZnSO4 or ZnO supplementation of broiler diets on growth performance and loss of uric acid N and total N from manure. A total of 240, 1-d-old broiler males were used for this experiment. Each dietary treatment was replicated 3 times with 10 birds per replicate. Chicks were fed a control diet for the first 6 d and then treatment diets for the next 12 d. There were 8 dietary treatments: the control, CuSO4-20, ZnSO4-500, ZnSO4-1,000, ZnSO4-1,500, ZnO-500, ZnO-1,000, and ZnO-1,500 containing 0, 0, 500, 1,000, 1,500 ppm supplemental Zn as ZnSO4 and 500, 1,000, and 1,500 ppm supplemental Zn as ZnO, respectively. A 300-g sample of the broiler manure from each treatment was incubated in a pan for 3 wk at room temperature. After incubation, samples were collected for the measurement of total N and uric acid N. Weight gain, feed consumption, and feed efficiency of chicks fed the diets supplemented with 1,500 ppm Zn as ZnSO4 were significantly lower than those of the other treatments, whereas the ZnO treatments had no negative effects on growth performance. After the 21-d incubation, the uric acid-N levels of manure from chicks fed the ZnO-1,000 treatment were significantly higher than those of manure from chicks fed the ZnSO4-500. The manure from chicks fed the Zn-supplemented diets had significantly less total N loss compared with that from chicks fed the control. The manure from chicks fed ZnO-1,500 had significantly less total N loss than that from chicks fed the other treatment diets. This study indicated that the Zn treatments significantly reduced nitrogen loss in poultry manure, and ZnO could be a better Zn source to prevent nitrogen loss to the atmosphere without any detrimental effect on growth performance.

Zinc supplementation at conventional doses does not improve the disturbance of taste perception in hemodialysis patients.

OBJECTIVE: To determine the effect of zinc supplementation on taste perception in a group of hemodialysis patients. DESIGN AND SETTING: Double-blind randomized placebo-controlled study in a teaching hospital dialysis unit. PATIENTS: Fifteen stable hemodialysis patients randomized to placebo (6 male, 2 female; median age, 67; range, 30 to 72 years) or treatment (5 male, 2 female; median age, 60; range, 31 to 76 years). INTERVENTION: Treatment group received zinc sulfate 220 mg per day for 6 weeks, and the placebo group received an apparently identical dummy pill. MAIN OUTCOME MEASURES: Taste scores by visual analogue scales, normalized protein catabolic rate and plasma, whole blood and red cell zinc levels. RESULTS: At baseline, sweet and salt tastes were identified correctly by both groups. Sour was often confused with salt. Sour solutions of different concentrations were not distinguishable. Taste scores were not different after 6 weeks for either group. There was no significant increment in zinc levels or normalized protein catabolic rate for either group. CONCLUSION: We found a disturbance of taste perception in hemodialysis patients, particularly for the sour modality, which was not corrected by this regimen of zinc supplementation. These results cast doubts on the conclusions of earlier studies that indicated an improvement in taste after zinc supplementation.

Cofortification of iron-fortified flour with zinc sulfate, but not zinc oxide, decreases iron absorption in Indonesian children.

BACKGROUND: Iron deficiency is a major nutritional concern in developing countries, and food fortification is a common strategy to treat it. In Indonesia wheat flour is fortified with 60 mg Fe/kg, but because of increasing concerns about marginal zinc status in at-risk populations, consideration is being given to cofortifying flour with zinc. However, little is known about the effect of zinc fortification of flour on iron bioavailability or about the optimum form of zinc supplementation. OBJECTIVE: We measured iron and zinc bioavailability from wheat-flour dumplings containing 25 g flour fortified with 60 mg Fe/kg, either alone or with 60 mg Zn/kg as zinc oxide or as zinc sulfate. DESIGN: Ninety children aged 4-8 y were recruited and assigned randomly to the 3 groups; 86 completed the study. Iron and zinc absorption were measured with established stable-isotope methods. RESULTS: Iron absorption from the flour fortified with iron only was good (15.9 +/- 6.8%), but when corrections were made for hemoglobin concentrations, it was significantly lower from the flour cofortified with zinc sulfate (11.5 +/- 4.9%; P < 0.05) but not from the flour cofortified with zinc oxide (14.0 +/- 8.9%). Zinc absorption was not significantly different between the zinc oxide and zinc sulfate cofortified flours (24.1 +/- 8.2% compared with 23.7 +/- 11.2%; P = 0.87). CONCLUSIONS: Iron and zinc appear to be highly bioavailable from foods made from fortified flour, but zinc sulfate cofortification may have a detrimental effect on iron absorption.