Dietary Chromium Supplementation Research Articles

Effects of dietary chromium and ascorbic acid supplementation on digestion of nutrients, serum antioxidant status, and mineral concentrations in laying hens reared at a low ambient temperature.

This experiment was conducted to evaluate the effects of chromium (chromium picolinate, CrPic) and vitamin C (L-ascorbic acid) supplementation on the digestion of nutrients and serum concentration of some antioxidant vitamins and minerals of laying hens (Hy-Line) reared at a low ambient temperature (6.8 degrees C). One hundred twenty laying hens (32 wk old) were divided into 4 groups, 30 hens per group. The laying hens were fed either a basal diet or the basal diet supplemented with either 400 microg of Cr/kg diet, 250 mg of L-ascorbic acid/kg diet, or 400 microg of Cr plus 250 mg L-ascorbic acid/kg diet. The digestibility of nutrients (DM, OM, CP, and EE) increased by the supplementation of chromium and vitamin C (p < 0.05). Supplemental chromium and vitamin C also increased serum vitamin C and E but decreased malondialdehyde concentrations (p < 0.05). Additionally, supplemental chromium and vitamin C caused an increase in the serum concentrations of Fe, Zn, Mn, and Cr (p < 0.05) but a decrease in Cu concentration. The results of the present study showed that each dietary supplement influenced most of the parameters measured in a similar way. Also, a combination of the two supplements resulted in an additive effect, and supplementing a combination of vitamin C (250 mg/kg of diet) and chromium (400 microg Cr/kg diet) may offer a potential protective management practice in preventing cold-stress-related depression in the performance of laying hens.

Optimal dietary concentration of chromium for alleviating the effect of heat stress on growth, carcass qualities, and some serum metabolites of broiler chickens.

This study was conducted to determine the effects of chromium (chromium picolinate, CrPic) supplementation at various levels (0, 200, 400, 800, or 1200 microg/kg of diet) on performance, carcass characteristics, and some serum metabolites of broiler chickens (Ross) reared under heat stress (32.8 degrees C). One hundred fifty old male broilers were randomly assigned to 5 treatment groups, 3 replicates of 10 birds each. The birds were fed either a control diet or the control diet supplemented with either 200, 400, 800, or 1200 microg Cr/kg of diet. Increased supplemental chromium resulted in an increase in body weight (p = 0.01, linear), feed intake (p < or = 0.05, linear), and carcass characteristics (p < or = 0.05, linear) and improved feed efficiency (p = 0.01, linear). Increased supplemental chromium decreased serum corticosterone concentration (p = 0.01, linear), whereas it increased serum insulin and T3 and T4 concentrations (p = 0.01). Serum glucose and cholesterol concentrations decreased (p = 0.01), whereas protein concentrations increased linearly (p = 0.001) with higher dietary chromium supplementation. Results of the present study conclude that a supplementation of diet with chromium at 1200 ppb can alleviate the detrimental effects of heat stress in broiler.

Health discussions on the Internet: A study of knowledge communication through citations

The Internet is a convenient but complex source for health information used by an increasing number of health consumers. Especially for people suffering from a chronic illness (e.g., diabetes), information seeking forms a part of the daily management of the disease, a “project of life.” This study of Web texts examines the citation patterns for a specific and controversial health issue: the beneficial or hazardous use of dietary chromium supplementation in diabetes self-management. Texts from different categories of Web sources (scientific, professional, educational, and commercial sources, as well as diabetes discussion groups) were analyzed in order to study how knowledge is transferred between sources, and how diabetics participating in discussion groups refer to and make sense of the information from different sources on the Internet. The citation patterns suggest that deviations from the traditional models of scientific knowledge dissemination can occur in the Internet environment.

Effects of dietary chromium picolinate supplementation on egg production, egg quality and serum concentrations of insulin, corticosterone, and some metabolites of Japanese quails

The effect of chromium (chromium picolinate, CrPic) supplementation on egg production, egg quality and serum concentrations of insulin, corticosterone and some metabolites of Japanese quails (Coturnix coturnix japanica) was evaluated. One hundred and fifty laying Japanese quails (45-d-old) were divided into five groups, 30 birds per group. The quails were fed either a control diet containing 1285.96 μg chromium (Cr)/kg of diet or the control diet supplemented with either 200 μg of Cr/kg of diet, 400 μg of Cr/kg of diet, 800 μg of Cr/kg of diet or 1200 μg of Cr/kg of diet. Increased supplemental chromium resulted in an increase in body weight ( P = 0.05, linear), feed intake ( P = 0.05, linear), egg production ( P = 0.01, linear), and also improved feed efficiency ( P = 0.01, linear). Increased supplemental chromium decreased ( P = 0.05, linear) egg shape index, whereas linearly increased egg weight ( P = 0.01), eggshell weight ( P = 0.01), eggshell thickness ( P = 0.01), albumen index ( P = 0.01), albumen weight ( P = 0.05), yolk index ( P = 0.05),yolk weight ( P = 0.01), and egg specific gravity ( P = 0.05). Serum insulin concentration linearly increased ( P = 0.01), whereas corticosterone concentration linearly decreased ( P = 0.05) as dietary chromium supplementation increased. Serum glucose and cholesterol concentrations decreased ( P = 0.01), while protein concentrations increased linearly ( P = 0.001) with higher dietary chromium supplementation. The results of the present study show that chromium supplementation, particularly at 1200 ppb, increases the performance, egg quality, and serum insulin concentrations of Japanese quails.

Effects of chromium nicotinate on performance, carcase characteristics and blood chemistry of growing turkeys

1. The objective of this trial was to study the effects of chromium nicotinate (Cr) supplementation on the performance, carcase characteristics and blood constituents of 9 to 22 week-old male turkeys. 2. Fifty-four 8-week-old male turkeys weighing 2.9 ± 0.28 kg were allocated at random into 9 groups with 3 dietary treatments and 3 replicates. The dietary treatment was different dietary concentrations of chromium in the basal diet, to provide 0 (control), 1 or 3 mg/kg. The feeding trial lasted for 14 weeks. 3. Results showed that 1 mg/kg chromium supplementation significantly improved weight gain and food intake at 9 to 18 weeks of age but did not significantly influence performance at 19 to 22 week of age. The breast and thigh muscle were significantly increased in birds receiving 1 mg/kg chromium supplementation but were decreased by 3 mg/kg of supplementation. 4. Dietary chromium supplementation did not significantly influence other serum constituents, including insulin, HDL, VLDL+LDL, HDL‐C, VLDL‐C+LDL‐C, total protein, albumin, and γ -globulin at 18 and 22 weeks of age. 5. The serum triacylglycerol (TG) and uric acid contents were significantly increased, while glycerol and α -globulin were significantly reduced by 3 mg/kg chromium supplementation. However, 1 mg/kg chromium supplementation significantly reduced serum cholesterol and glycerol at 18-weeks old. At 22 weeks of age, 1 mg/kg chromium supplementation significantly increased serum glucose and decreased the uric acid concentration whereas 3 mg/kg chromium supplementation significantly increased the creatinine concentration and decreased β -globulin concentration.

Effects of dietary chromium picolinate supplementation on performance and plasma concentrations of insulin and corticosterone in laying hens under low ambient temperature.

This experiment was conducted to evaluate the effects of chromium (chromium picolinate) on performance and plasma concentrations of insulin and corticosterone of laying hens (Ross Brown) under a low ambient temperature (6.9 degrees C). One hundred and twenty laying hens (46 weeks old) were divided into four groups, 30 hens per group. The laying hens were fed either a control diet containing 710.3 p.p.b. chromium or the control diet supplemented with 100, 200 or 400 microg chromium/kg diet. Increasing supplemental chromium increased live weight change (p < or = 0.001, linear) and egg production (p < or = 0.001, linear) and also improved feed efficiency linearly (p < or = 0.001). Live weight change and egg production also had quadratic responses (p < or = 0.001) to increasing chromium supplementation. Plasma insulin concentration increased linearly (p < or = 0.001), whereas corticosterone concentration decreased linearly (p < or = 0.001) as dietary chromium supplementation increased. The results of this study indicate that supplemental dietary chromium, 200 p.p.b. in particular, had a positive effect on performance and increased the plasma insulin concentration of laying hens under cold stress.

The effects of dietary chromium supplementation on some blood parameters in sheep.

The effects of dietary inorganic chromium on some biochemical parameters were determined in lambs fed either a control diet or a 200-ppb or 400-ppb chromium-supplemented diet. The live weight of the animals were measured and jugular blood samples were collected prior to supplementation (d 0) and on d 20, 40, and 55. On d 55, three animals from each group were slaughtered to measure subcutaneous fat. Sera were analyzed for glucose, triglyceride, total cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol, total protein, albumin, ALT, AST, and GGT levels. Chromium supplementation had no significant effect on live weight, but subcutaneous fat was reduced significantly in both chromium groups. There was a slight decrease in glucose concentrations in the 200-ppb chromium group, although only the differences on d 55 were significant. Triglyceride levels in both chromium groups were lower than the control group with marked differences in the 400-ppb chromium group. HDL cholesterol levels increased in both treatment groups compare to control, although the differences in the 400-ppb chromium group on d 40 were significant. Serum Cr concentrations slightly but not significantly increased in both chromium groups. No significant differences were found in total and LDL cholesterol, total protein, albumin, ALT, AST, and GGT levels. In conclusion, chromium supplementation may affect carbohydrate and lipid metabolisms and lipid deposition in lambs.

Lack of effect of dietary chromium supplementation on glucose tolerance, plasma insulin and lipoprotein levels in patients with type 2 diabetes.

Chromium is essential for the regulation of insulin action, thereby influencing carbohydrate and lipid metabolism. An uncontrolled pilot study was designed to measure the habitual daily intake of chromium in a group of healthy individuals with type 2 diabetes and to monitor the effect of daily supplementation with high chromium yeast on glucose tolerance, plasma insulin and lipoproteins. Twelve free-living adults with type 2 diabetes underwent a glucose tolerance test (GTT) on recruitment, at 4 weeks (after a 7-d duplicate diet collection) and at 12 weeks (following 8 weeks daily supplementation with 100 micrograms of chromium). Urine samples were collected on the day before and the day of each GTT. Blood samples were taken at half hourly intervals for 3 hours during the GTT and the plasma glucose, cholesterol, triglyceride, HDL, LDL and insulin concentration measured. The chromium content of diets and urine samples was determined. Fasting glucose concentrations and glucose area under the curve profiles did not alter significantly post supplementation with the chromium rich yeast. No significant changes in insulin and lipoprotein concentrations were observed. The results of this study do not support the hypothesis that individuals with type 2 diabetes benefit from yeast-based chromium supplements (100 micrograms/day).

Increased chromium excretion in pregnancy is associated with insulin resistance

The purpose of this study was to evaluate the basic physiology of chromium excretion during normal pregnancy with particular reference to whether changes in excretion are related to any alterations in glucose handling or insulin sensitivity. Healthy pregnant women (n = 126) gave urine samples every 4 weeks from 16 weeks gestation to delivery and then 6 and 10 weeks post-partum. A subgroup of 12 volunteers provided fasting blood samples at 28 weeks gestation for the investigation of insulin sensitivity. Our current study provides clear evidence of persistent increased chromium loss in at least 22% of women experiencing a healthy pregnancy and further has highlighted significant differences in insulin resistance in women excreting increased levels of chromium. A 65% reduction in the sensitivity to insulin was apparent (P < 0.03). The data suggest the possibility that chromium may be being used preferentially by the fetus and that, in some women, dietary intake is insufficient to serve the needs of both fetus and mother. Dietary chromium supplementation for women who lose excessive chromium during pregnancy might restore maternal insulin sensitivity. J. Trace Elem. Exp. Med. 13:389–396, 2000. © 2000 Wiley-Liss, Inc.

Effect of Supplemental Chromium on Whole-Body Kinetics of Glucose, Lactate, and Propionate in Rams Fed a High Grain Diet

The isotope dilution technique of [6-3H]glucose, [U-14C]lactate and [1-14C]propionate was used to evaluate the effect of dietary chromium (Cr) supplementation on whole-body kinetics of glucose, lactate, and propionate in rams. Rams were fed a high grain diet at 2% of body weight with or without 0.5 ppm of supplemental Cr from chelated Cr for the initial 14 days, and then intake was increased to 2.5% at body weight for the last 9 days. Weight gain was enhanced (P < 0.01) with Cr supplementation. Plasma concentrations of glucose, lactate, and propionate were not influenced by Cr supplementation. Turnover rates of glucose and lactate, and their interconversion were also not influenced. Propionate turnover rate tended to increase (P = 0.11) and the conversion of propionate to glucose increased (P < 0.05) with Cr supplementation, leading the increased proportional contribution of propionate to glucose turnover rate (P < 0.05). Chromium supplementation may influence the contribution of each glucogenic substrate for glucose production in rams fed a high grain diet.

Effects of dietary chromium supplementation on cardiac mass, metabolic enzymes, and contractile proteins

Chromium, a popular but controversial micronutrient, can increase skeletal muscle growth when provided in supplemented quantities, presumably because of its suspected insulin like action. Whether chromium similarly affects cardiac muscle is an important issue because inappropriate cardiac growth can suggest decrements in cardiac performance. Therefore, the purpose of this study was to determine if chromium supplementation impacted contractile and metabolic properties of the heart. Male Sprague-Dawley rats received a semi-purified basal diet supplemented with 300 PPB chromium picolinate (CONTR), or supplemented with 1500 PPB chromium picolinate (SUPPLEM). After 12 weeks on the respective diets, animals were killed, and the left ventricles removed and analyzed for differences in cardiac metabolic and contractile proteins. Chromium supplementation failed to alter body weights, left ventricular mass, total protein content, and myofibrillar protein content, citrate synthase, or hexokinase activity. The amount of the high ATPase myosin isoform, V1 was diminished by 11% in the SUPPLEM group (p ≤ 0.05). These findings demonstrate that the adaptive response of the heart to dietary chromium supplementation is limited to changes in the myosin isoform. These changes may provide the heart with a more economical contractile apparatus without compromising cardiac performance.

Dietary Chromium Supplementation with or without Somatotropin Treatment Alters Serum Hormones and Metabolites in Growing Pigs without Affecting Growth Performance

Twenty-four castrated male pigs were used in a 2 x 2 treatment array to determine the main effects of and interactions between dietary chromium supplementation and pituitary porcine somatotropin (ppST) administration on growth performance and serum hormone and metabolite concentrations. The treatments were 1) control (basal diet); 2) chromium (basal diet+300 micrograms/kg diet added trivalent chromium as chromium picolinate); 3) ppST (100 micrograms/(kg body wt.d); and 4) chromium+ppST. Treatments were administered when pigs weighed between 30 and 60 kg. Blood was collected when pigs weighted 45 and 60 kg. All pigs treated with ppST exhibited improvements in growth performance (P < 0.05). Pigs given chromium showed no improvements in growth rate, feed efficiency or composition of gain. Measurements at 60 kg body weight revealed that ppST increased the cholesterol:HDL cholesterol ratio (P < 0.05). Chromium lowered serum insulin and glucose concentrations relative to controls (P < 0.05) and normalized the increase in glucose and insulin resulting from ppST treatment. No ppST x chromium interactions were noted, suggesting these changes in glucose and insulin metabolism are exerted through different mechanisms. These results indicate that chromium does not affect growth performance of young growing pigs. Chromium does normalize altered hormone and metabolite concentrations resulting from ppST treatment.

Alterations of Rat Adipose Tissue Metabolism Associated with Dietary Chromium Supplementation

Net free fatty acid release from adipose tissue taken from male rats fed a stock diet unsupplemented with chromium was significantly greater than that from adipose tissue taken from chromium-supplemented rats. This enhanced net lipolysis was unaccompanied by any evidence of a compensatory increase in reesterification. Specifically, the glycerokinase-catalyzed direct phosphorylation of glycerol, which might have provided an alternate supply of alpha-glycerophosphate for reesterification in the absence of glycolytic production of alpha-glycerophosphate, was significantly reduced. These animals also showed an abnormal glucose tolerance response. In contrast, male rats fed a purified diet unsupplemented with chromium appeared to be marginally chromium-deficient as judged by a glucose tolerance test but did not show any alterations in adipose tissue metabolism attributable to the adequacy of chromium nutriture.