Clozapine Worsens Glucose Intolerance, Nonalcoholic Fatty Liver Disease, Kidney Damage, and Retinal Injury and Increases Renal Reactive Oxygen Species Production and Chromium Loss in Obese Mice

Clozapine is widely employed in the treatment of schizophrenia. Compared with that of atypical first-generation antipsychotics, atypical second-generation antipsychotics such as clozapine have less severe side effects and may positively affect obesity and blood glucose level. However, no systematic study of clozapine’s adverse metabolic effects—such as changes in kidney and liver function, body weight, glucose and triglyceride levels, and retinopathy—was conducted. This research investigated how clozapine affects weight, the bodily distribution of chromium, liver damage, fatty liver scores, glucose homeostasis, renal impairment, and retinopathy in mice fed a high fat diet (HFD). We discovered that obese mice treated with clozapine gained more weight and had greater kidney, liver, and retroperitoneal and epididymal fat pad masses; higher daily food efficiency; higher serum or hepatic triglyceride, aspartate aminotransferase, alanine aminotransferase, blood urea nitrogen, and creatinine levels; and higher hepatic lipid regulation marker expression than did the HFD-fed control mice. Furthermore, the clozapine group mice exhibited insulin resistance, poorer insulin sensitivity, greater glucose intolerance, and less Akt phosphorylation; their GLUT4 expression was lower, they had renal damage, more reactive oxygen species, and IL-1 expression, and, finally, their levels of antioxidative enzymes (superoxide dismutase, glutathione peroxidase, and catalase) were lower. Moreover, clozapine reduced the thickness of retinal cell layers and increased iNOS and NF-κB expression; a net negative chromium balance occurred because more chromium was excreted through urine, and this influenced chromium mobilization, which did not help overcome the hyperglycemia. Our clozapine group had considerably higher fatty liver scores, which was supported by the findings of lowered adiponectin protein levels and increased FASN protein, PNPLA3 protein, FABP4 mRNA, and SREBP1 mRNA levels. We conclude that clozapine can worsen nonalcoholic fatty liver disease, diabetes, and kidney and retinal injury. Therefore, long-term administration of clozapine warrants higher attention.

Dietary Chromium Restriction of Pregnant Mice Changes the Methylation Status of Hepatic Genes Involved with Insulin Signaling in Adult Male Offspring

Maternal undernutrition is linked with an elevated risk of diabetes mellitus in offspring regardless of the postnatal dietary status. This is also found in maternal micro-nutrition deficiency, especial chromium which is a key glucose regulator. We investigated whether maternal chromium restriction contributes to the development of diabetes in offspring by affecting DNA methylation status in liver tissue. After being mated with control males, female weanling 8-week-old C57BL mice were fed a control diet (CON, 1.19 mg chromium/kg diet) or a low chromium diet (LC, 0.14 mg chromium/kg diet) during pregnancy and lactation. After weaning, some offspring were shifted to the other diet (CON-LC, or LC-CON), while others remained on the same diet (CON-CON, or LC-LC) for 29 weeks. Fasting blood glucose, serum insulin, and oral glucose tolerance test was performed to evaluate the glucose metabolism condition. Methylation differences in liver from the LC-CON group and CON-CON groups were studied by using a DNA methylation array. Bisulfite sequencing was carried out to validate the results of the methylation array. Maternal chromium limitation diet increased the body weight, blood glucose, and serum insulin levels. Even when switched to the control diet after weaning, the offspring also showed impaired glucose tolerance and insulin resistance. DNA methylation profiling of the offspring livers revealed 935 differentially methylated genes in livers of the maternal chromium restriction diet group. Pathway analysis identified the insulin signaling pathway was the main process affected by hypermethylated genes. Bisulfite sequencing confirmed that some genes in insulin signaling pathway were hypermethylated in livers of the LC-CON and LC-LC group. Accordingly, the expression of genes in insulin signaling pathway was downregulated. There findings suggest that maternal chromium restriction diet results in glucose intolerance in male offspring through alterations in DNA methylation which is associated with the insulin signaling pathway in the mice livers.

Maternal Chromium Restriction Leads to Glucose Metabolism Imbalance in Mice Offspring through Insulin Signaling and Wnt Signaling Pathways

An adverse intrauterine environment, induced by a chromium-restricted diet, is a potential cause of metabolic disease in adult life. Up to now, the relative mechanism has not been clear. C57BL female mice were time-mated and fed either a control diet (CD), or a chromium-restricted diet (CR) throughout pregnancy and the lactation period. After weaning, some offspring continued the diet diagram (CD-CD or CR-CR), while other offspring were transferred to another diet diagram (CD-CR or CR-CD). At 32 weeks of age, glucose metabolism parameters were measured, and the liver from CR-CD group and CD-CD group was analyzed using a gene array. Quantitative real-time polymerase chain reaction (qPCR) and Western blot were used to verify the result of the gene array. A maternal chromium-restricted diet resulted in obesity, hyperglycemia, hyperinsulinemia, increased area under the curve (AUC) of glucose in oral glucose tolerance testing and homeostasis model assessment of insulin resistance (HOMA-IR). There were 463 genes that differed significantly (>1.5-fold change, p < 0.05) between CR-CD offspring (264 up-regulated genes, 199 down-regulated genes) and control offspring. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and STRING (Search Tool for the Retrieval of Interacting Genes/Proteins) analysis revealed that the insulin signaling pathway and Wnt signaling pathway were in the center of the gene network. Our study provides the first evidence that maternal chromium deficiency influences glucose metabolism in pups through the regulation of insulin signaling and Wnt signaling pathways.

Effects of Maternal Chromium Restriction on the Long-Term Programming in MAPK Signaling Pathway of Lipid Metabolism in Mice

It is now broadly accepted that the nutritional environment in early life is a key factor in susceptibility to metabolic diseases. In this study, we evaluated the effects of maternal chromium restriction in vivo on the modulation of lipid metabolism and the mechanisms involved in this process. Sixteen pregnant C57BL mice were randomly divided into two dietary treatments: a control (C) diet group and a low chromium (L) diet group. The diet treatment was maintained through gestation and lactation period. After weaning, some of the pups continued with either the control diet or low chromium diet (CC or LL), whereas other pups switched to another diet (CL or LC). At 32 weeks of age, serum lipid metabolism, proinflammatory indexes, oxidative stress and anti-oxidant markers, and DNA methylation status in adipose tissue were measured. The results indicated that the maternal low chromium diet increased body weight, fat pad weight, serum triglyceride (TG), low-density lipoprotein cholesterol (LDL), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA), and oxidized glutathione (GSSG). There was a decrease in serum reduced/oxidized glutathione (GSH/GSSG) ratio at 32 weeks of age in female offspring. From adipose tissue, we identified 1214 individual hypomethylated CpG sites and 411 individual hypermethylated CpG sites in the LC group when compared to the CC group. Pathway analysis of the differential methylation genes revealed a significant increase in hypomethylated genes in the mitogen-activated protein kinase (MAPK) signaling pathway in the LC group. Our study highlights the importance of the MAPK signaling pathway in epigenetic changes involved in the lipid metabolism of the offspring from chromium-restricted dams.

Chromium, zinc and magnesium status in type 1 diabetes

PURPOSE OF REVIEW

Chromium, zinc, and magnesium are involved in insulin signal transduction, glucose metabolism, and cellular antioxidative defense. This review details the statuses of chromium, zinc, and magnesium in type 1 diabetes patients.

RECENT FINDINGS

Blood levels of trace elements (especially magnesium and zinc) were lower in type 1 diabetes patients than in controls and were even lower in type 1 diabetes patients with poor glycemic control. Studies with mouse models have shown that chromium and magnesium supplementation alleviated diabetes-induced complications and improved glycemic control.

SUMMARY

Many studies indicated positive correlations between decreased levels of serum chromium, zinc, and magnesium and poor glycemic control. The supplementation of type 1 diabetes patients with zinc, magnesium, and chromium may help to control diabetes and prevent diabetes-related oxidative injuries, but require further study.

[Micronutrients and diabetes, the case of minerals]

Minerals are essential nutrients for the body, are of inorganic nature which gives them the characteristic of being resistant to heat, are involved in a lot of chemical reactions in metabolism, regulating electrolyte balance, in maintaining bone, in the process of blood clotting and the transmission of nerve impulses, particularly its role as enzyme cofactors confers a key role in various physiological processes. Glucose homeostasis involves a fine coordination of events where hormonal control by insulin plays a key role. However, the role of minerals like magnesium, zinc, chromium, iron and selenium in the diabetes is less obvious and in some cases may be controversial. This review shows the knowledge of these five elements and their correlation with diabetes.

Correlation of hair mineral concentrations with insulin resistance in Korean males

Calcium and magnesium that are associated with insulin resistance play an antagonistic role with each other in cells. This study was conducted to investigate the relationship between hair mineral concentrations and insulin resistance in Korean adult males. A total of 123 male subjects (63 patients with metabolic syndrome and 60 normal control patients) were recruited and fasting plasma glucose, total cholesterol, triglyceride, as well as HDL cholesterol levels, HOMA-IR, and hair mineral concentrations were measured. The ratio of calcium/magnesium in hair showed a significantly positive correlation with the HOMA-IR (r = 0.191, P = 0.038) and insulin (r = 0.198, P = 0.031). The result of multiple regression analysis after adjusting the age also showed a significant correlation of the Ca/Mg ratio with HOMA-IR (R² = 0.115, P = 0.047). The hair chromium concentration was lower in the metabolic syndrome group than in the control group, and it showed a significantly negative correlation with the fasting blood glucoseand the triglyceride. The result of this study showed that insulin resistance increased as the ratio of Ca/Mg increased, or as the chromium concentration in hair decreased.

Zinc, copper, iron, and chromium concentrations in young patients with type 2 diabetes mellitus

Homeostasis of trace elements can be disrupted by diabetes mellitus. On the other hand, disturbance in trace element status in diabetes mellitus may contribute to the insulin resistance and development of diabetic complications. The aim of present study was to compare the concentration of essential trace elements, zinc, copper, iron, and chromium in serum of patients who have type 2 diabetes mellitus (n = 20) with those of nondiabetic control subjects (n = 20). The serum concentrations of zinc, copper, iron, and chromium were measured by means of an atomic absorption spectrophotometer (Shimadzu AA 670, Kyoto, Japan) after acid digestion. The results of this study showed that the mean values of zinc, copper, and chromium were significantly lower in the serum of patients with diabetes as compared to the control subjects (P < 0.05). Our results show that deficiency of some essential trace elements may play a role in the development of diabetes mellitus.

Comparison of dietary intake between fixed orthodontic patients and control subjects

BACKGROUND

Adolescence is a period of rapid physiological and psychological development which is associated with an increased demand in nutritional requirements. Orthodontic therapy is also commonly initiated during this phase of life and nutritional intake may also change during treatment.

AIMS

To compare the nutrient intakes of adolescents wearing fixed orthodontic appliances and a control group matched for age and gender.

METHOD

A total of 180 patients aged between 15 and 17 years participated in this study (90 in the study group and 90 controls). Demographic data were collected by questionnaire and dietary intake was assessed using a 24-hour memory recall and was analysed using Dietplan6 software (Forestfield Software Ltd, UK). Comparisons between groups were assessed by the Independent sample t-test dnd the SPSS was used for statistical analysis.

RESULTS

Orthodontic patients consumed a similar number of total calories, protein and carbohydrate (p > 0.05); however, they had a greater intake of total fat, saturated fat, monosaturated fat, polysaturated fat, linolenic fat, linoleic fat and cholesterol and significantly lower intake of fibre, chromium and beta-carotene (p < 0.05) compared with the Control group. The intake of other macro- and micro-nutrients did not differ significantly between groups.

CONCLUSIONS

Adolescents receiving orthodontic treatment have an altered dietary intake that can be harmful to their health. As adolescents are at a critical stage of development and dietary intake is of particular importance, it is recommended that targeted nutritional guidance is provided to patients during orthodontic treatment.

Chronic maternal dietary chromium restriction modulates visceral adiposity: probable underlying mechanisms

OBJECTIVE

We demonstrated previously that chronic maternal micronutrient restriction altered the body composition in rat offspring and may predispose offspring to adult-onset diseases. Chromium (Cr) regulates glucose and fat metabolism. The objective of this study is to determine the long-term effects of maternal Cr restriction on adipose tissue development and function in a rat model.

RESEARCH DESIGN AND METHODS

Female weanling WNIN rats received, ad libitum, a control diet or the same with 65% restriction of Cr (CrR) for 3 months and mated with control males. Some pregnant CrR mothers were rehabilitated from conception or parturition and their pups weaned to control diet. Whereas some CrR offspring were weaned to control diet, others continued on CrR diet. Various parameters were monitored in the offspring at three monthly intervals up to 15-18 months of age.

RESULTS

Maternal Cr restriction significantly increased body weight and fat percentage, especially the central adiposity in both male and female offspring. Further, the expression of leptin and 11 beta-hydroxysteroid dehydrogenase 1 genes were significantly increased in CrR offspring of both the sexes. Adipocytokine levels were altered in plasma and adipose tissue; circulating triglyceride and FFA levels were increased, albeit in female offspring only. Rehabilitation regimes did not correct body adiposity but restored the circulating levels of lipids and adipocytokines.

CONCLUSIONS

Chronic maternal Cr restriction increased body adiposity probably due to increased stress and altered lipid metabolism in WNIN rat offspring, which may predispose them to obesity and associated diseases in later life.

Chromium status and glucose tolerance in Saudi men with and without coronary artery disease

Chromium deficiency is associated with impaired glucose tolerance (IGT) and dyslipidemia. Hence, the objective of the current study was to investigate chromium status among Saudi men with and without established cardiovascular disease (CVD) and its relationship to glucose tolerance, lipid profile and other established CVD risk factors. We measured serum and urine chromium concentrations, fasted lipid profile, plasma glucose, and serum lipid peroxide in 130 Saudi men with an established history of myocardial infarction and 130 age-matched controls without established CVD. Patients with established CVD had higher serum triglycerides (p < 0.05) and plasma glucose (p < 0.0001) and lower serum and urinary chromium concentrations (p < 0.0001) than controls. Serum chromium was inversely correlated with plasma glucose among cases and controls (r = -0.189, p < 0.05 and r = -0.354, p < 0.00001, respectively). Plasma glucose (OR 1.127, CI 1.0-1.269, p < 0.05), serum chromium (OR 0.99, CI 0.985-0.995, p < 0.0001), and urinary chromium (OR 0.988, CI 0.981-0.995, p < 0.001) were independently associated with the presence of established coronary disease applying this model. While chromium metabolism appears to be altered in individuals with CVD, it is unclear whether chromium supplementation would be effective in CVD prevention among patients with IGT. This would need to be tested in long-term outcome trials.

The effects of feeding with different levels of zinc and chromium on plasma thiobarbituric acid reactive substances and antioxidant enzymes in rats

This study was designed to investigate the effects of supplementation and deficiency of dietary chromium (Cr), zinc (Zn) and combination of zinc and chromium on lipid peroxidation and antioxidant enzymes. A total of 84 male Wistar albino rats were fed rat chow containing different levels of Zn and Cr throughout the 84 days. Blood samples were collected for analysis of Thiobarbituric acid reactive substances (TBARS), Superoxide dismutase (SOD), Catalase (CAT) and Glutathione peroxidase (GSH-Px). TBARS concentrations in rats fed high-Cr diet, high-Zn and Cr diet and low-Zn diet were significantly higher than those determined in the control group (p < or = 0.05). CAT activities in rats fed high-Cr diet were significantly higher than those observed in the control group. Cu-Zn SOD and GSH-Px activities were significantly higher in rats fed high-Cr diet, high-Zn and Cr diet, low-Zn diet, and low-Zn and Cr diet when compared to the activities found in the controls. These results suggest that trivalent chromium supplementation increase antioxidant enzymes by enhancement of lipid peroxidation, but Zn supplementation does not have any effect on lipid peroxidation. Also Zn deficiency resulted in increased lipid peroxidation, SOD and GSH-Px activities because of the oxidative stress caused by zinc deficiency.

Clinical studies on chromium picolinate supplementation in diabetes mellitus--a review

Chromium (Cr) picolinate (CrPic) is a widely used nutritional supplement for optimal insulin function. A relationship among Cr status, diabetes, and associated pathologies has been established. Virtually all trials using CrPic supplementation for subjects with diabetes have demonstrated beneficial effects. Thirteen of 15 clinical studies (including 11 randomized, controlled studies) involving a total of 1,690 subjects (1,505 in CrPic group) reported significant improvement in at least one outcome of glycemic control. All 15 studies showed salutary effects in at least one parameter of diabetes management, including dyslipidemia. Positive outcomes from CrPic supplementation included reduced blood glucose, insulin, cholesterol, and triglyceride levels and reduced requirements for hypoglycemic medication. The greater bioavailability of CrPic compared with other forms of Cr (e.g., niacin-bound Cr or CrCl(3)) may explain its comparatively superior efficacy in glycemic and lipidemic control. The pooled data from studies using CrPic supplementation for type 2 diabetes mellitus subjects show substantial reductions in hyperglycemia and hyperinsulinemia, which equate to a reduced risk for disease complications. Collectively, the data support the safety and therapeutic value of CrPic for the management of cholesterolemia and hyperglycemia in subjects with diabetes.

Low toenail chromium concentration and increased risk of nonfatal myocardial infarction

Chromium intake may increase insulin sensitivity, glucose tolerance, and the ratio of high density lipoprotein cholesterol to low density lipoprotein cholesterol. However, the epidemiologic evidence on the association between chromium and cardiovascular disease is very limited. To determine whether low toenail chromium concentrations were associated with risk of nonfatal myocardial infarction, the authors conducted an incident, population-based, case-control study in eight European countries and Israel in 1991-1992. Cases (n = 684) were men with a first diagnosis of myocardial infarction recruited from the coronary units of participating hospitals. Controls (n = 724) were men selected randomly from population registers (five study centers) or through other sources, such as hospitalized patients (three centers), general practitioners' practices (one center), or relatives or friends of cases (one center). Toenail chromium concentration was assessed by neutron activation analysis. Average toenail chromium concentrations were 1.10 mug/g in cases (95% confidence interval: 1.01, 1.18) and 1.30 mug/g in controls (95% CI: 1.21, 1.40). Multivariate odds ratios for quintiles 2-5 were 0.82 (95% CI: 0.52, 1.31), 0.68 (95% CI: 0.43, 1.08), 0.60 (95% CI: 0.37, 0.97), and 0.59 (95% CI: 0.37, 0.95). Toenail chromium concentration was inversely associated with the risk of a first myocardial infarction in men. These results add to an increasing body of evidence that points to the importance of chromium for cardiovascular health.

Effect of chromium on the insulin resistance in patients with type II diabetes mellitus

INTRODUCTION

Chromium deficiency in diabetic patients is a debatable problem. The prevailing opinion suggests the presence of low serum concentrations in such patients and therefore an early, long-term addition of chromium to the standard therapy is recommended.

PURPOSE

The aim of the present study was to evaluate the effect of chromium on the insulin resistance in diabetic patients with type II diabetes mellitus.

MATERIAL AND METHODS

We have studied a total of 34 overweight patients with type II diabetes mellitus, who were distributed in two study sub-groups--patients with very good metabolic control and patients with bad control. For sixty days the patients of both groups received 30 microg of chromium picolinate as food additive. We measured the serum concentration of chromium (using atom-absorption methods), immune-reactive insulin and the insulin resistance index at baseline and at the end of the two-month period.

RESULTS

The serum concentrations of chromium was significantly lower in diabetic patients than in the healthy individuals used as controls (2.18 +/- 0.87 nmol/l versus 4.03 +/- 0.96 nmol/l; p < 0.001). We found a significant decrease of the immune-reactive insulin and the insulin resistance index after a two-month application of chromium 30 microg daily (1 tablet of chrome picolinate). The effects of this trace element are analysed in the light of an improved first phase of secretion of insulin or facilitated post-receptor insulin sensibility as a way of potentiating the insulin action.

CONCLUSION

Chromium included early in the complex therapy of diabetes is beneficial in the reduction of the degree of insulin resistance.

Effects of chromium and copper depletion on lymphocyte reactivity to mitogens in diabetes-prone BHE/cdb rats

OBJECTIVE

The purpose of this study was to measure effects of chromium (Cr) and copper (Cu) depletion on lymphocyte reactivity to mitogens in diabetes-prone BHE/cdb rats.

METHODS

A 2 x 2 factorial research design was used, and 40 BHE/cdb rats were fed with Cr- and/or Cu-depleted diets or adequate Cr and/or Cu diets for 21 wk. Cr and Cu concentrations in diets and mineral concentrations of tissues of BHE/cdb rats were measured by using flame and graphite furnace atomic absorption spectrometry. Three glucose tolerance tests were performed to monitor the development of diabetes or glucose intolerance at weeks 12, 18, and 21. Splenocytes (2 x 10(6)) were incubated with phytohemagglutinin-l (PHA-L), concanavalin A (ConA), and lipopolysaccharides (LPSs), respectively, for 72 h. Four hours before the end of the incubation, splenocytes were pulsed with 3H-thymidine. The 3H-thymidine uptake by lymphocytes was used to calculate a stimulation index.

RESULTS

According to glucose tolerance tests, these rats did not develop diabetes or impaired glucose tolerance throughout the study. Average Cr concentrations were 0.98 to 1.03 mg Cr/kg of diet in adequate Cr diets and 8.2 to 14 micrograms Cr/kg of diet in Cr-depletion diets. Average Cu concentrations were 3.6 to 6.4 mg Cu/kg of diet in adequate Cu diets and 1.1 to 1.3 mg Cu/kg of diet in Cu-depletion diets. Organ weights did not differ significantly among treatment groups at the end of the study. Cr or Cu depletion significantly affected iron, zinc, and magnesium concentrations in the liver. A significant interactive effect of Cr and Cu was observed on lymphocyte proliferation with PHA-L stimulation at 25 micrograms/mL (P < 0.006). However, there were no significant effects of dietary treatment on lymphocyte proliferation with 10 micrograms/mL of PHA-L, ConA, or LPS stimulations.

CONCLUSIONS

When Cr and Cu were adequate in the diets, there was an enhanced effect of Cu or Cr on lymphocyte proliferation. However, when Cr was depleted in the diet, there was a suppressive effect of Cu on lymphocyte proliferation. This result indicates that adequate amounts of Cr and Cu in the diet support the immune system.

[Chromium and insulin resistance]

Since as early as the 50s of the last century, it has been known that chromium is essential for normal glucose metabolism. Too little chromium in the diet may lead to insulin resistance. However, there is still no standard against which chromium deficiency can be established. Nevertheless, chromium supplements are becoming increasingly popular. Various systematic reviews have been unable to demonstrate any effects of chromium on glycaemic regulation (possibly due partly to the low dosages used), but there is a slight reduction in body weight averaging 1 kg. In a double-blind randomised placebo-controlled trial in a Chinese population with type-2 diabetes mellitus, supplementation with 1000 micrograms of chromium led to a fall in the glycosylated haemoglobin level (HbA1c) by 2%. Toxic effects of chromium are seldom seen; recently, however, the safety of one of the dosage forms of chromium, chromium picolinate, has been questioned. One should be aware that individual patients with type-2 diabetes mellitus may have an increased risk of hypoglycaemic episodes when taking chromium supplements as self-medication.

A scientific review: the role of chromium in insulin resistance

Chromium is an essential mineral that appears to have a beneficial role in the regulation of insulin action and its effects on carbohydrate, protein and lipid metabolism. Chromium is an important factor for enhancing insulin activity. Studies show that people with type 2 diabetes have lower blood levels of chromium than those without the disease. Insulin resistance is the common denominator in a cluster of cardiovascular disease risk factors. One out of every five Americans has metabolic syndrome. It affects 40% of people in their 60s and 70s. Insulin resistance, with or without the presence of metabolic syndrome, significantly increases the risk of cardiovascular disease. Insulin resistance is present in two serious health problems in women; polycystic ovarian syndrome (PCOS) and gestational diabetes. Several studies have now demonstrated that chromium supplements enhance the metabolic action of insulin and lower some of the risk factors for cardiovascular disease, particularly in overweight individuals. Chromium picolinate, specifically, has been shown to reduce insulin resistance and to help reduce the risk of cardiovascular disease and type 2 diabetes. Dietary chromium is poorly absorbed. Chromium levels decrease with age. Supplements containing 200-1,000 mcg chromium as chromium picolinate a day have been found to improve blood glucose control. Chromium picolinate is the most efficacious form of chromium supplementation. Numerous animal studies and human clinical trials have demonstrated that chromium picolinate supplements are safe.

A test for adequacy of chromium nutrition in humans--relation to type 2 diabetes mellitus

When Na(2)51CrO(4) is added to blood the 51CrO(4)(2-) ions enter the erythrocytes readily, and nearly exclusively, and are reduced to 51Cr(III) ions. We have observed that a fraction of these ions becomes bound to the cell membrane in a concentration which seemingly depends on that of the dietary derived intracellular Cr(III) ions. Thus, when constant amounts of 51CrO(4)(2-) ions enter constant amounts of erythrocytes, the resulting 51Cr(III) ions become bound to the cell membrane in a concentration that varies inversely as the initial, intracellular concentration of Cr(III) ions which, in turn, depends directly on the adequacy of chromium nutrition. Therefore, we have determined an arbitrary set of conditions under which the concentration of 51Cr(III) ions bound to the erythrocyte membrane becomes an indicator of the adequacy of chromium nutrition. The application of this test to 25 Type 2 diabetes mellitus subjects and 35 normal controls, both randomly selected, indicates that the concentrations of membrane bound 51Cr(III) ions in the two groups were not significantly different. Consequently, it is concluded that the level of chromium nutrition which is normally adequate in humans has only a minor role, if any, in the genesis of Type 2 diabetes mellitus.

Trace metals and the elderly

The elderly are at nutritional risk as a result of multiple physiological, social, psychological, and economic factors. Elderly persons have a higher incidence of chronic diseases and associated intake of medications that may affect nutrient utilization. Social and economic conditions can adversely affect dietary choices and eating patterns. Physiological functions naturally decline with age, which may influence absorption and metabolism. Loneliness and reluctance to eat may complicate an already marginal situation. This article reviews specific trace metals in relation to the elderly. Our objectives are to provide Dietary Reference Intakes for older adults, to provide information on presenting features and functional consequences of trace metal deficiency, and to discuss potential effects and/or benefits of trace metal supplementation in the elderly.

The retinal pigment epithelium of Cr-deficient rats

The purpose of this study is to investigate the effect of Cr deficiency on the rat retina. Three-week-old Wistar Kyoto rats were divided into 2 groups. Cr-deficient rats were fed AIN-93G diet without Cr and deionized distilled water. Control rats were fed AIN-93G diet and deionized distilled water. The Cr and sugar concentrations in the whole blood and cholesterol concentration in the serum were measured. We observed the retina with an electron microscope, and counted phagocytized lamellar structures in the retinal pigment epithelium (RPE) before and after the start of light exposure on negative electron microscopic films. The whole blood Cr level of Cr-deficient rats was less than 0.2 microg/l. The blood sugar level of Cr-deficient rats was significantly higher than that of normal rats (p < 0.05). There were significantly more phagocytized lamellar structures in the RPE of Cr-deficient rats 1, 2, 7, 11 and 12 h after the start of light exposure than in that of normal rats (p < 0.05). However, no morphological abnormalities were found in the photoreceptor cells of Cr-deficient rats. Phagocytosis in the photoreceptor outer segment discs in the RPE was accelerated, but the pattern of the retinal circadian rhythm with maximum phagocytosis 2 h after exposure to light was unchanged. The Cr-deficient state may cause the membrane to degenerate, and phagocytosis of the photoreceptor outer segment discs in the RPE may be accelerated. This study provided an evidence of the nutritional importance of Cr in rat retina.

Epidemiological correlation between chromium content in gallstones and cholesterol in blood

The authors measured the chromium in gallstones and bile from patients in three areas (Kawasaki (a city adjacent to Tokyo) in Japan, Chiang Mai and Bangkok in Thailand) by means of neutron activation analysis. The chromium in three types of gallstones (cholesterol, pigment, and rare stones) and bile from patients living in Bangkok were evidently larger than those from patients living in Kawasaki and Chiang Mai. The high chromium intake by Bangkok patients continued from the start of gallstone formation until the time the stones were removed. The total-cholesterol, triglyceride, and hemoglobin A(1C) levels in the blood from Bangkok residents with high chromium intake over a long period were clearly lower than those of Japanese and Chiang Mai residents. The authors showed that the high dietary intake of chromium over a long period may play a role in the lowering of total-cholesterol, triglyceride, and hemoglobin A(1C) in blood.

Serum zinc, chromium, and iron concentrations in dogs with lymphoma and osteosarcoma

We compared serum concentrations of zinc, chromium, and iron in dogs with cancer to those of normal dogs. Dogs with lymphoma (n = 50) and osteosarcoma (n = 52) were evaluated. Dogs with lymphoma had significantly lower (P = .0028) mean serum zinc concentrations (mean +/- SD; 1.0 +/- 0.3 mg/L) when compared to normal dogs (1.2 +/- 0.4 mg/L). Dogs with osteosarcoma also had lower mean serum zinc concentrations (1.1 +/- 0.4 mg/L), but this difference was not significant (P = .075). Serum chromium concentrations were significantly lower in dogs with lymphoma (2.6 +/- 2.6 microg/L, P = .0007) and osteosarcoma (2.4 +/- 3.1 microg/L, P = .0001) compared to normal dogs (4.7 +/- 2.8 microg/L). Serum iron concentrations and total iron-binding capacity were significantly lower in dogs with lymphoma (110.8 +/- 56.7 microg/dL, P < .0001, and 236.6 +/- 45.6 microg/dL, P < .0001, respectively) and osteosarcoma (99.6 +/- 49.3 microg/dL, P < .0001, and 245.0 +/- 43.8 microg/dL, P = .0011, respectively) when compared to normal dogs (175.1 +/- 56.7 microg/dL and 277.1 +/- 47.4 microg/dL). Mean ferritin concentration was significantly higher in dogs with lymphoma (1291.7 +/- 63.0 microg/L) than in normal dogs (805.8 +/- 291.1 microg/L, P < .0001) and dogs with osteosarcoma (826.5 +/- 309.2 microg/L, P < .0001). Further investigation is needed to explore the clinical significance of these mineral abnormalities in dogs with cancer.

Experimental copper deficiency, chromium deficiency and additional molybdenum supplementation in goats--pathological findings

Secondary copper (Cu) deficiency, chromium (Cr) deficiency and molybdenosis (Mo) has been suggested to cause the "mysterious" moose disease in the southwest of Sweden. The present experiment was performed on goats to investigate the clinical, chemical, and pathological alterations after 20 months feeding of a semi-synthetic diet deficient in Cu and Cr. Four groups were included in the study: control group (n = 4), Cu-deficient group (group 1, n = 4), Cr-deficient group (group 2, n = 2) and Cu + Cr-deficient group (group 3, n = 3). Group 3 was additionally supplemented with tetrathiomolybdate during the last 2 months of the experiment. Main histopathological findings in groups 1 and 3 were the lesions in the liver, characterised by a severe active fibrosis, bile duct proliferation, haemosiderosis and mild necroses. Additionally, degenerative alterations of the exocrine pancreas were prominent in groups 1 and 3. Lesions in group 3 were more pronounced than in group 1. In group 3, the skin showed an atrophic dermatosis, while in group 2 a crusty dermatitis caused by Candida spp. was observed. This study shows that liver, pancreas and skin are mainly affected by a long term deficiency of copper and the findings are complicated by molybdenum application while chromium deficiency produced no histomorphological effects in our study.

Micronutrients and immune function in cattle

Complex inter-relationships exist between certain micronutrients, immune function and disease resistance in cattle. Several micronutrients have been shown to influence immune responses. The relationship between deficiencies of some micronutrients and disease resistance is less clear. A number of studies have indicated that Cr supplementation may improve cell-mediated and humoral immune response as well as resistance to respiratory infections in stressed cattle. With respiratory-disease challenge models Cr generally does not affect disease resistance. Deficiencies of Cu, Se, vitamin E and Co in cattle reduce the ability of isolated neutrophils to kill yeast and/or bacteria. Cu deficiency reduces antibody production, but cell-mediated immunity is generally not altered. However, Cu deficiency appears to reduce production of interferon and tumour necrosis factor by mononuclear cells. Numerous studies have linked low vitamin E and/or Se status to increased susceptibility of dairy cows to intramammary infections. In contrast to findings in laboratory animals, marginal Zn deficiency does not appear to impair antibody production or lymphocyte responsiveness to mitogen stimulation in ruminants. Co deficiency has been associated with reduced resistance to parasitic infections. It is well documented that vitamin A-deficient animals are more susceptible to various types of infections. beta-Carotene, possibly via its antioxidant properties, may affect immune function and disease resistance independent of its role as a precursor of vitamin A.

Chromium, exercise, and body composition

Chromium is an essential trace element involved in the metabolism of carbohydrates, lipids, and proteins mainly by increasing the efficiency of insulin. Chromium deficiency affects the maintenance of normal glucose tolerance and healthy lipid profiles. The Estimated Safe and Adequate Daily Dietary Intake for chromium is 50 to 200 microg/d for adults. However, the dietary intake of chromium in humans is often suboptimal. Chromium assessment has proven to be a challenge due to the low amounts of chromium present in biological materials and the absence of a reliable indicator of chromium status. Recently, chromium has been touted as an agent for increasing lean body mass and decreasing percent body fat. This article reviews the various studies that have been conducted to investigate the relationship of chromium with exercise and body composition.

Experimental copper and chromium deficiency and additional molybdenum supplementation in goats. II. Concentrations of trace and minor elements in liver, kidneys and ribs: haematology and clinical chemistry

Since the mid-1980s a previously undescribed disease has affected moose in south-western Sweden. Investigations made to reveal evidence of a viral aetiology have proved unsuccessful. Trace element studies in apparently healthy moose shot during regular hunting suggested a trace element imbalance, with excessive molybdenum uptake causing secondary copper deficiency. The results also indicated a possible chromium deficiency. To verify this hypothesis, an experimental study was performed in male goats fed a semi-synthetic diet for 1.5 years. The animals were kept and treated in four groups: Controls, Cu-deficient group (group 1), Cr-deficient group (group 2), and combined Cu- and Cr-deficient group with additional supplementation of tetrathiomolybdate for 10 weeks at the end of the study (group 3). The present paper presents tissue contents of trace and minor elements, haematology and clinical chemical parameters. Feed consumption and weight development, as well as pathological and histopathological investigations, were also performed in this study, but these results are presented elsewhere. Changes in trace element concentrations were determined by comparing groups 1, 2 and 3 with the control group. Increased concentrations were observed for Al, Ca, Co, Fe, Mo, Pb, Se in the liver; for Al, Cd, Co, Cr, Mo in the kidneys; and for Mn and Mo in the ribs. Considerable accumulation of Mn in ribs seems to be a useful way to determine oxidative stress. Decreases in Mg and P in all organs and blood serum is characteristic of Cu deficiency and molybdenosis. Also the ratio of Ca/Mg was increased as the result of tissue lesions causing an intracellular increase in Ca and decrease in Mg. The trace element changes observed in group 1 were enhanced by the Mo supplementation in group 3, resulting in characteristic patterns, 'spectra' of changes. The alterations were not as remarkable in group 2 as in the two other groups. However, Cr deficiency considerably influenced Al, Co, V and to a smaller extent also Mn in ribs. In groups 1 and 2, only a few minor changes were detected in the haematological parameters, probably caused by increased adrenal activity after transportation of the animals. In group 3, severe anaemia was present but also a leukopenia. For the different clinical chemical parameters measured, all three groups showed changes, explained mainly by the altered activity of enzymes induced by trace element deficiencies and imbalance. Impaired carbohydrate and lipid metabolism was seen in groups 1 and 3, with increased concentrations of glucose, lactate and triglycerides in serum. Increased concentrations of total bilirubin were measured in all three groups (bile stasis was also seen post mortem). A considerably increased concentration of serum urea was found in group 3, although there were no indications of renal insufficiency or dehydration. Regarding hormones, a substantial decrease was seen in thyroxine (T4) in group 3 as a result of the molybdenosis, but a minor decrease was also seen in group 1. Insulin on the other hand showed increased levels in group 3--and especially in group 2 due to the Cr deficiency but also affected by the molybdenosis. As could be expected, Cu deficiency (groups 1 and 3) caused low levels of caeruloplasmin, secondarily affecting the Fe metabolism in these animals. Protein abnormalities, detected as altered electrophoretic patterns of serum proteins, were also seen mainly in group 3. The findings were also confirmed by multivariate data analysis, where PCA revealed the overall impact of the deficiencies, and PLS regression coefficients indicated the influence on the various analytes.

Experimental copper and chromium deficiency and additional molybdenum supplementation in goats. I. Feed consumption and weight development

Secondary Cu deficiency, Cr deficiency and molybdenosis were suggested causes of the 'mysterious' disease afflicting moose (Alces alces L.) in a region in south-west Sweden affected by acid rain. A model experiment with goats was performed to study the clinical chemical parameters, determine the tissue contents of trace and minor elements, to perform pathological and histopathological investigations and to compare the findings with those in moose disease. Twenty 3-month-old male goats were assigned to four dietary treatments (five animals each) in an experiment lasting for 20 months. The four groups in the study were: control group, Cu-deficient group (group 1), Cr-deficient group (group 2), and Cu- and Cr-deficient group (group 3). The animals were fed a basic semi-synthetic diet. At the end of the study the three surviving animals of group 3 were supplemented with additional tetrathiomolybdate (TTM) during the last 2 months. Feed consumption and weight development of the animals were monitored and are presented. The feed consumption of the two Cu-deficient groups of goats (group 1 and group 3) supported the previously described observations in copper deficiency in ruminants, e.g. decreased appetite and feed intake. A previously unreported effect of Cr deficiency in ruminants is now described in goats. Chromium deficiency at adequate Cu supplementation (group 2), caused increased lipid synthesis and a weight gain of 32 kg compared with that of the control group (20 kg). A possible explanation for this unexpected weight increase in only Cr deficiency is discussed. It is concluded that the feeding experiment does not support the hypothesis concerning the relation of Cr deficiency to the moose disease.

Is chromium a trace essential metal?

If chromium is an essential metal it must have a specific role in an enzyme or cofactor, and a deficiency should produce a disease or impairment of function. To date, no chromium-containing glucose tolerance factor has been characterized, the purpose of the low-molecular-weight chromium-binding protein is questionable, and no direct interaction between chromium and insulin has been found. Furthermore, chromium3+ is treated like the toxic metals arsenic, cadmium, lead and mercury in animals. Chromium3+ may be involved in chromium6+-induced cancers because chromium6+ is converted to chromium3+ in vivo, and chromium3+ is genotoxic and mutagenic. Although there is no direct evidence of chromium deficiencies in humans, dietary supplements exist to provide supraphysiological doses of absorbable chromium3+. Chromium3+ may act clinically by interfering with iron absorption, decreasing the high iron stores that are linked to diabetes and heart disease. If so, this would make chromium3+ a pharmacological agent, not an essential metal.

Effect of chromium supplementation on glucose tolerance and lipid profile

OBJECTIVES

To investigate chromium status of the adult population in the western region of Saudi Arabia and the possibility of using serum chromium status measurement as indicator of this status.

METHODS

The effect of chromium supplement on glucose tolerance and lipid profile was studied in 44 normal, free living adults. 200mg chromium/day as CrCL3 or a placebo was given in a double blind cross-over study, with 8 weeks experimental periods. Fasting, 1 hour and 2 hour post glucose challenge (75 g of glucose) glucose, serum fructosamine, total cholesterol, high-density lipoprotein-cholesterol, triglycerides, chromium and dietary intakes were estimated at the beginning and the end of each stage.

RESULTS

Mean serum chromium increased significantly after supplement (P<.001) indicating proper absorption of the element. Supplement did not effect the total cholesterol, however, the mean high-density lipoprotein-cholesterol level was significantly increased (P<.001), the mean triglycerides levels significantly decreased (P<.001), and the mean fructosamine level significantly decreased (P<.05). In addition, chromium supplement effected 1 hour and 2 hour post glucose challenge glucose levels in subgroups of subjects with 2 hour glucose level > 10% above or below fasting level and significantly differing to it (P<.05 in both cases), by decreasing or increasing them significantly (P<.05 in all cases) so that the 2 hour mean became not significantly different to the fasting mean. Since no significant changes in weight, dietary intake or habits were found, and placebo had no effect, all noted biochemical changes were attributed to chromium.

CONCLUSION

Improved glucose control, and lipid profile following chromium supplement suggests the presence of low chromium status in the studied population. However, serum chromium could not be recommended for use as an indicator of chromium status as subjects with widely varying levels responded favorably to the chromium supplement.

Overproduction of insulin in the chromium-deficient rat

The hypothesis that the insulin secretory hyperresponsiveness observed in rats with diet-induced insulin resistance may be a basic characteristic of dietary chromium (Cr) deficiency was evaluated. Two groups of weanling rats were fed ad libitum a purified diet containing 64% sucrose, 20% casein, 5% corn oil, and the recommended levels of vitamins and minerals without added Cr. Cr-deficient (-Cr) rats were provided with distilled drinking water only, while Cr-supplemented (+Cr) rats received water containing 5 ppm Cr as CrCl3. A third group of rats fed a commercial chow diet served as sucrose controls. Effects of Cr deficiency were assessed by comparing fasting levels of glucose, insulin, and plasma lipids in blood samples collected biweekly from the -Cr and +Cr groups over a 3-month period. Both groups of rats fed the low-Cr sucrose diet developed a transient hyperinsulinemia and hyperlipidemia relative to the chow-fed control rats. There were significant effects of Cr supplementation on plasma triglycerides during the initial 2 weeks of dietary adaptation. Effects of the low-Cr diet were evaluated after the 12-week period by comparing the insulin response area and glucose clearance during a 40-minute intravenous glucose tolerance test (IVGTT). The rates of glucose clearance (KG) in -Cr and +Cr rats were similar (4.2 +/- 1.0 and 4.3 +/- 0.8%/min, respectively) and were comparable to the K(G) in chow-fed rats (4.6 +/- 0.8). In contrast, insulin secretory responses in -Cr rats were exaggerated (area, 14,083 +/- 3,399 microU/mL x min), being twofold greater (P < .05) relative to the +Cr group (6,183 +/- 864). The insulin secretory response area in chow-fed rats (7,081 +/- 408 microU/mL x min) was similar to the value in the +Cr group. These observations provide support for the hypothesis that Cr deficiency can lead to elevated insulin secretory responses to glucose.

Reversal of corticosteroid-induced diabetes mellitus with supplemental chromium

AIMS

To determine if the stress of corticosteroid treatment increases chromium (Cr) losses and if corticosteroid-induced diabetes (steroid diabetes) can be reversed by supplemental chromium.

METHODS

The effects of corticosteroid treatment on chromium losses of 13 patients 2 days prior to steroid administration and the first 3 days following treatment were determined. Since steroid-induced diabetes was associated with increased chromium losses and insufficient dietary chromium is associated with glucose intolerance and diabetes, we treated three patients with steroid-induced diabetes with 600 microg per day of chromium as chromium picolinate.

RESULTS

Urinary chromium losses following corticosteroid treatment increased from 155+/-28 ng/d before corticosteroid treatment to 244+/-33 ng/d in the first 3 days following treatment. Chromium supplementation of patients with steroid-induced diabetes resulted in decreases in fasting blood glucose values from greater than 13.9 mmol/l (250 mg/dl) to less than 8.3 mmol/l (150 mg/dl). Hypoglycaemic drugs were also reduced 50% in all patients when given supplemental chromium.

CONCLUSIONS

These data demonstrate that corticosteroid treatment increases chromium losses and that steroid-induced diabetes can be reversed by chromium supplementation. Follow-up, double-blind studies are needed to confirm these observations.

Maternal and fetal insulin-like growth factor system and embryonic survival during pregnancy in rats: interaction between dietary chromium and diabetes

Chromium (Cr) depletion may exacerbate hyperglycemia and negative outcomes of pregnancy in the streptozotocin (STZ) diabetic pregnant rat model through the regulation of the insulin-like growth factor (IGF) system. To test this hypothesis, 40 female rats, all fed a low Cr diet (i.e., 70 microgram Cr/kg diet ) from 21 d of age, were randomly assigned one of four treatments, applied on Day 1 of pregnancy, in a 2 x 2 factorial design: 1) very low Cr diet (40 microgram Cr/kg diet) + citrate buffer injection, 2) very low Cr diet + STZ injection (30 mg STZ/kg body wt in citrate buffer), 3) adequate Cr diet (2 mg Cr [from added CrK(SO4)2]/kg diet) + citrate buffer injectionand 4) adequate Cr diet + STZ injection. Blood and tissues were collected on Day 20 of pregnancy. Chromium depletion increased (P < 0.05) urinary hydroxyproline excretion, 22-kDa IGF binding protein (IGFBP) concentration and litter size but decreased (P < 0. 05) placental wt, percentage of protein per fetus, and fetal IGF-I and -II concentrations. Chromium had no effect (P > 0.10) on maternal hormones, 32-kDa IGFBP, glucose, or placental and fetal hydroxyproline concentrations. Diabetes decreased (P < 0.05) maternal wt gain, embryonic survival, litter size, mean pup wt and maternal insulin concentrations, increased (P < 0.05) maternal blood glucose, IGF-I concentrations and maternal hydroxyproline excretion but did not affect fetal concentrations of hormones, IGFBP, glucose or hydroxyproline. Interaction between chromium and diabetes tended (P < 0.10) to affect maternal IGF-II concentrations, but had no effect on other maternal or fetal variables. In conclusion, maternal chromium depletion did not exacerbate hyperglycemia or pregnancy outcome in STZ-induced diabetic rats, but may negatively affect fetal protein content by decreasing fetal IGF-II concentrations. Diabetes may negatively affect fetal growth through its effect on maternal glucose, insulin and IGF-I.

Deliberations and evaluations of the approaches, endpoints and paradigms for boron, chromium and fluoride dietary recommendations

The 10th edition (1989) of the Recommended Dietary Allowances provided estimated safe and adequate daily dietary intakes (ESADDI) for chromium and fluoride and summarized the substantial evidence for boron essentiality in animals. New endpoints, approaches and paradigms to use to formulate dietary guidance for these elements were reviewed by a discussion group that met as part of a national workshop. Deliberations of the group are summarized to facilitate future discussions on dietary guidance for these elements. The category, "provisional RDA" was recommended to replace the current ESADDI category because of the ambiguities associated with the ESADDI. A provisional RDA would be defined for a dietary substance that meets one of two sets of criteria: class 1, clear evidence of essentiality but uncertain or limited quantitative data or endpoints to define dietary requirements; and class 2, strong evidence of essentiality, and clear nutritional benefit based on reasonably certain quantitative data, but lack of clear information on function or endpoints to use for deficiency dietary requirements. A summary of background information and possible approaches for assigning provisional RDAs for boron, chromium and fluoride is presented.

[Medicinal plants--concentrators of chromium. The role of chromium in alkaloid metabolism]

Mass screening of medicinal plants of the flora of Russia (196 species) was performed for chromium content. A total of 124 species-chromium concentrators were found, in which the chromium content markedly exceeded the mean values, this excess being 4- to 6-fold in 54 species, 7- to 3-fold in 62 species, and 37- to 114-fold in seven species. The greatest capacity of chromium accumulation was shown for the sand immortelle, foxglove, Alexandrian laurel, Greek valerian, marsh cudweed, adenostilis, and lobelia. These species are considered as potential sources of chromium for correction of its deficiency in humans. Some mechanisms underlying the effect of chromium on metabolism of alkaloids derivative of quinolizidine, tropane, isoquinoline, and indole, were deciphered.

Neurologic symptoms due to possible chromium deficiency in long-term parenteral nutrition that closely mimic metronidazole-induced syndromes

BACKGROUND

We previously described a patient on home parenteral nutrition (HPN) who developed glucose intolerance and neuropathy that only responded to an infusion of chromium. A patient on HPN who had neuropathy and glucose intolerance was studied. He was also on metronidazole, which could have caused the neuropathy, but the symptoms and signs persisted.

METHODS

Baseline clinical examination, nerve conduction studies, serum vitamin and trace element levels, and glucose tolerance were measured. Then, 250 micrograms of trivalent chromium as the chloride salt was infused daily for 2 weeks. The above studies were repeated.

RESULTS

The patient at baseline had peripheral neuropathy of the axonal type and was glucose intolerant. Serum chromium was raised in this patient above the reference range. Despite raised serum levels, the infusion of chromium resulted in clinical remission that was marked 4 days after starting the infusion. Normalization of nerve conduction also occurred within 3 weeks of the initial study.

CONCLUSIONS

Neuropathy and glucose intolerance may occur despite increased serum chromium levels and respond to chromium infusion. The previous use of drugs such as metronidazole should not exclude chromium as a potential treatment for neuropathy in HPN patients.

Vitamin and mineral deficiencies which may predispose to glucose intolerance of pregnancy

There is an increased requirement for nutrients in normal pregnancy, not only due to increased demand, but also increased loss. There is also an increased insulin-resistant state during pregnancy mediated by the placental anti-insulin hormones estrogen, progesterone, human somatomammotropin; the pituitary hormone prolactin; and the adrenal hormone, cortisol. If the maternal pancreas cannot increase production of insulin of sustain normoglycemia despite these anti-insulin hormones, gestational diabetes occurs. Gestational diabetes is associated with excessive nutrient losses due to glycosuria. Specific nutrient deficiencies of chromium, magnesium, potassium and pyridoxine may potentiate the tendency towards hyperglycemia in gestational diabetic women because each of these four deficiencies causes impairment of pancreatic insulin production. This review describes the pathophysiology of the hyperglycemia and the nutrient loss in gestational diabetes and further postulates the mechanism whereby vitamin/mineral supplementation may be useful to prevent or ameliorate pregnancy-related glucose intolerance.