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PubMed1993

[Skin reactivity and the biological assessment of chromium exposure].

Subject to the examination are 140 workers from the plant for hydraulic products "Iv. Tenev", town of Yambol. The dermatological examination embraces 57 workers from shop 21, 49 from shop 24 and control group of 24 persons. The examination establishes skin changes in 24.6% of the workers from shop 21 and in 38.7% in those from shop 24. In the same workers were proved occupational dermatoses respectively in 5.3% for these of the first shop and in 14.3% for those of the second shop. The results of the test of 10 workers from shop 24 gave positivation of the test with 0.5% chromic anhydride at 10.5%. The studies for toxicokinetics of chromium in the examined workers proved its high values in urine, erythrocytes and nails. Raised chromium levels are established in the urine of those working with chromium in comparison with the control group (p 0.0001). There is a good correlation dependence between the chromium in urine and in erythrocytes (r = 0.71; n = 45%; p < 0.0001). Persons, eliminating significant quantities of chromium in the urine have higher values of chromium in erythrocytes, which shows that the chromium entering the organism of workers in contact with chromium is 6-valent. The connection with the chromium in urine and in nails is more lightly expressed and is statistically insignificant (r = 0.35; n = 29; p < 0.05), which is due to the fact that the chromium in urine reflects the near exposure in time, while chromium in nails--the level of exposure before 6-8 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Bulgaria↗
PubMed2001

A subtoxic interactive toxicity study of ethanol and chromium in male Wistar rats.

The purpose of this study was to evaluate the interactive toxicity of ethanol with potassium dichromate (K2Cr2O7-chromium). Young, male Wistar rats (100-120 g) were divided into four groups of five or six animals each and were dosed, through water, with 10% ethanol (vol./vol.) or 25 ppm chromium or were dosed with a combination of ethanol+chromium at the same concentrations for a period of 22 weeks ad libitum and were maintained on normal diet. Control animals were maintained on a normal diet and water for the same period. The serum succinate dehydrogenase and liver total triglyceride levels were significantly reduced in the three treated groups. The serum alkaline phosphatase levels were significantly reduced in ethanol-treated rats, and there was no significant change in the acid phosphatase activity. Serum aspartate and alanine aminotransferase levels in the three treated groups were significantly increased. The liver glycogen significantly decreased in both the ethanol-treated and the chromium-treated rats. There was a significant increase in liver total cholesterol levels in chromium-treated rats. Total glutathione levels were significantly decreased in the livers of ethanol-treated and ethanol+chromium-treated rats. To further substantiate these findings, a histological examination of the liver and kidneys was undertaken. The livers of alcohol-treated animals showed altered hepatic architecture in the centrilobular and periportal areas, with increased sinusoidal space (space of Disse), vacuolation, and necrosis of hepatocytes. Similar changes were observed in a histological examination of the livers of chromium-treated rats, except that the damage to the hepatocytes was more confined to the periportal area. Moreover, histological examination of the livers of ethanol+chromium-treated rats revealed uniform damage in the centrilobular and periportal areas, as was observed in the groups treated either with ethanol or chromium. The histological examination of the kidneys in the three treated groups revealed significant damage to the renal tubules and Bowman's capsule, which showed vacuolation and degeneration of the basement membrane. These findings correlate well with the serum enzyme levels found in the treated groups. It is evident from this study that chronic ethanol consumption sensitizes the liver to the toxic action of agents such as chromium. It leads to impairment of the biochemical functions in the liver, and it causes liver and kidney damage. Long-term simultaneous exposure to ethanol and chromium may cause severe health problems in people who are alcoholics and work in chrome-plating and leather-tanning industries.

Alkaline Phosphatase↗
PubMedDate not supplied

Oral chromium picolinate and control of glycemia in insulin-treated diabetic dogs.

Chromium is an essential dietary trace mineral involved in carbohydrate and lipid metabolism. Chromium is required for cellular uptake of glucose, and chromium deficiency causes insulin resistance. Chromium supplementation may improve insulin sensitivity and has been used as adjunct treatment of diabetes mellitus in humans. In this study, 13 dogs with naturally acquired diabetes mellitus were treated with insulin for 3 months, then with insulin and chromium picolinate for 3 months. Dogs weighing <15 kg (33 lb: n = 9) were administered 200 microg of chromium picolinate PO once daily for I month, then 200 microg of chromium picolinate twice daily for 2 months. Dogs weighing >15 kg (n = 4) received 200 microg of chromium picolinate once daily for 2 weeks, then 200 microg twice daily for 2 weeks, then 400 microg twice daily for 2 months. Type of insulin, frequency of insulin administration, and diet were kept constant, and insulin dosage was adjusted, as needed, to maintain optimal control of glycemia. Mean body weight, daily insulin dosage, daily caloric intake, 10-hour mean blood glucose concentration, blood glycated hemoglobin concentration, and serum fructosamine concentration were not markedly different when dogs were treated with insulin and chromium picolinate, compared with insulin alone. Adverse effects were not identified with chromium picolinate administration. Results of this study suggest that, at a dosage range of 20-60 microg/kg/d, chromium picolinate caused no beneficial or harmful effects in insulin-treated diabetic dogs.

Administration, Oral↗
PubMed1998

Distribution of a stable isotope of chromium (53Cr) in serum, urine, and breast milk in lactating women.

To determine the fate and distribution of chromium during lactation, six lactating women (25-38 y old) were given three doses of the tracer 53Cr (7.55 micromol/d, or 400 microg/d) on days 1, 2, and 3 of the study. Diet records, blood samples taken while subjects were fasting, and 24-h composite milk and urine samples were collected from day 0 to day 6. Fasting blood samples, morning milk samples, and 24-h urine samples were also collected on days 8, 10, 15, 30, 60, and 90. 53Cr and natural and total chromium concentrations in biological fluids were measured with gas chromatography-mass spectrometry and total urinary chromium was measured with atomic-absorption spectrometry. 53Cr was detectable in serum 2 h after dosing and continued to be detected from day 30 to day 60. Changes in total serum chromium concentration in response to the oral dose suggested that chromium concentrations in blood were not tightly regulated. 53Cr was not detected in breast milk and no significant changes in natural chromium concentration in milk were observed in response to the oral doses, suggesting that breast-milk chromium concentrations are independent of intake. The estimated chromium intake of exclusively breast-fed infants was 2.5 nmol/d (0.13 microg/d), below the lower end of the range of estimated safe and adequate daily dietary intakes (10-40 microg/d) for infants 0-6 mo of age. The baseline chromium concentration in urine and the minimum 53Cr absorption in lactating women were comparable with values for nonpregnant, nonlactating subjects. Chromium losses in breast milk do not appear to be compensated for via increased absorption or decreased excretion.

Administration, Oral↗
PubMed1976

Hair sampling for chromium content following Charnley hip arthroplasty.

The chromium content of hair has been studied by neutron activation analysis of samples from 62 patients following a Charnley unilateral or bilateral hip arthroplasty by an artificial joint of stainless steel against polyethylene, inserted three to five years previously. The patients lived in the North Wales area of the British Isles. Hair chromium content was also studied in 51 control subjects of similar age to that of the patients, from the same geographical area and often from the patients' own households. Chromium content was recorded as parts per million (ppm) of hair weighed and analyzed in the state received, without preliminary ashing or chemical "washing" of the samples in the laboratory. Fifty of the 51 control subjects showed less than 2 ppm chromium in hair; one showed 2-5 ppm; none showed more than 5 ppm. Fifty-nine of the 62 patients showed less than 2 ppm chromium in hair; three showed 2-5 ppm; none showed more than 5 ppm. Attention is drawn to certain practical aspects when collecting hair samples for chromium analysis. The use and validity of hair sampling as one method of screening for systemic chromium accumulation following implant surgery is discussed. The method may be a useful adjunct to monitoring of chromium levels in blood samples. In this preliminary study, hair sampling has given no evidence of any major risk of systemic chromium accumulation in patients using a Charnley arthroplasty for periods of up to five years; no conclusion can be made concerning periods longer than this. The findings do not exclude systemic reactions of the hypersensitivity type, since this type of reaction could develop to only small amounts of chromium.

Acetabulum↗
PubMed1996

A role for molecular oxygen in the formation of DNA damage during the reduction of the carcinogen chromium (VI) by glutathione.

Although well-established as carcinogens, the way in which chromium (VI) compounds exert their carcinogenic, mutagenic, and DNA-damaging potential remains obscure. It is clear that inside cells chromium(VI) is activated to its ultimate carcinogenic form by reducing agents including glutathione (GSH). The present study is intended to clarify if Fenton mechanisms are likely to be important in the formation of DNA lesions by chromium(VI) in combination with GSH. In buffer solutions which were treated to remove Fenton-active metal ions as well as in those not further purified, chromate and GSH induced similar numbers of single-strand breaks (SSB) in isolated PM2 DNA. Molecular oxygen was found to be essential for the formation of SSB, but chromium(V) species arising from chromate/GSH, unless activated by oxygen, appeared to be unreactive toward DNA. Upon addition of Mn(II) to solutions of chromium(VI) and GSH a diminution of Mn(II) ESR signals was observed, good evidence for the presence of chromium(IV) species. Using gas chromatography/mass spectrometry in selective ion-monitoring mode and high-performance liquid chromatography with electrochemical detection, we were able to show that Cr(VI)/GSH failed to induce base modifications typical of hydroxyl radical attack on DNA. Experimental conditions which readily induced SSB gave rise to the formation of chromium-DNA adducts, clearly demonstrating that the generation of these two DNA lesions is not mutually exclusive. We conclude that models which ascribe the induction of chromium-DNA adducts to chromium(V) and the generation of oxidative DNA damage including SSB to hydrogen peroxide are oversimplistic. It is not necessary to invoke a mechanism requiring the presence of added hydrogen peroxide to account for the ability of Cr(VI)/GSH to cause SSB. Our findings suggest that the combination of GSH, molecular oxygen, and chromium(VI) can damage DNA via non-Fenton pathways.

Carcinogens, Environmental↗
PubMed1997

Occurrences, uses, and properties of chromium.

Chromium is the 21st most abundant element in the Earth's crust with a mean concentration in United States soils of about 40 mg/kg. Although it exists in several oxidation states, the zero, trivalent, and hexavalent states are the most important in commercial products and the environment. Nearly all naturally occurring chromium is in the trivalent state, usually in combination with iron or other metal oxides. Although only about 15% of the chromium mined is used in the manufacture of chemicals, most applications of chromium utilize the chemistry of chromium. For instance, the "stainless" nature of stainless steel is due to the chemical properties of the chromium oxides which form on the surface of the alloy. Similarly, the protective properties of chrome plating of metals, chromated copper arsenate (CCA) treatment of wood, and chrome tanning of leather are all dependent on chromium chemistry. The key to these uses is that under typical environmental and biological conditions of pH and oxidation-reduction potential, the most stable form of chromium is the trivalent oxide. This form has very low solubility and low reactivity resulting in low mobility in the environment and low toxicity in living organisms. In this paper the chemical properties of chromium are discussed for the major commercial products in the context of the Eh-pH diagram for chromium.

Chromium↗
PubMed1998

Serum and urine chromium concentrations in elderly diabetics.

The serum and urine chromium concentrations of 57 diabetics and 55 normal fasting subjects were determined by atomic absorption spectrometry (AAS). Our results indicate that the chromium concentration ranges of serum and urine for diabetics are 0.22-0.36 and 4.54-5.90 microg/L, respectively, significantly lower than 0.66-0.84 7.80-9.68 microg/L for the normal (P<0.001), which implies that the elderly diabetics probably lack chromium. Further, it was found that the urine chromium level of the female diabetics was substantially higher than that of the male in the same age group (P<0.01), whereas the serum chromium level was almost the same. However, the urine chromium concentration increases with aging, no matter who the diabetics or the controls are. The serum chromium concentrations of the 24 cases patients with 2-h oral glucose tolerance test (OGTT) were significantly lower than that of those with empty stomach, whereas the urine chromium exhibits a contrary tendency. Our data indicate that the chromium lost and excreted from human body increases with aging and is related to the diabetics. Thus, it is recommended to supplement a certain amount of chromium to the elderly diabetics according to their nutritional level.

Aged↗
PubMed2006

Study on chromium (VI) reduction kinetics by Pseudomonas aeruginosa using a combined system of acoustic wave impedance analyzer and UV-vis spectrophotometer.

A novel system combining acoustic wave impedance (AWI) analyzer with UV-vis spectrophotometer was developed for the study of chromium (VI) reduction kinetics by Pseudomonas aeruginosa. AWI gave information about the growth of Pseudomonas aeruginosa, and UV-vis spectrophotometer gave information about the concentration of chromium (VI) simultaneously. A combined system response model, for chromium (VI) reduction kinetics at lower initial chromium (VI) concentrations, was derived and proved based on the novel system. Taking into account the effect of bacterial growth on chromium (VI) reduction, the new model successfully simulated chromium (VI) bioremediation process. By fitting chromium (VI) reduction data toward the derived model, the kinetic parameters related to the process were obtained. When the concentration of peptone was 10 g L(-1), the half-velocity reduction rate constant K (C) and the maximum specific chromium (VI) reduction rate constant nu(max) were 0.7682 mg chromium (VI) L(-1) and 2.5814 x 10(-12) mg chromium (VI) cells(-1) h(-1), respectively. It was found that the combined system can provide real-time, reliable, and two-dimensional kinetic information, and can be applied to study other biological processes.

Algorithms↗
PubMed2004

Insulin sensitising action of chromium picolinate in various experimental models of diabetes mellitus.

Although chromium is an essential element for carbohydrate and lipid metabolism, its effects in diabetic patients are still debated. We have studied the effect of 6 week treatment with chromium picolinate (8 microg/ml in drinking water) in streptozotocin (STZ)-induced type 1 and type 2 diabetic rat models. The mechanism of anti-diabetic action of chromium picolinate was studied using C2C12 myoblasts and 3T3-L1 adipocytes. Chromium picolinate significantly decreased the area under the curve over 120 min for glucose of both STZ-induced type 1 (40mg/kg, i.v. in adult rats) and type 2 (90 mg/kg, i.p. in 2 day old rat neonates) diabetic rats without any significant change in area under the curve over 120 min for insulin as compared to controls. The composite insulin sensitivity index and insulin sensitivity index (KITT) values of both type 1 and type 2 diabetic rats were increased significantly by chromium picolinate. Treatment with chromium picolinate produced a significant decrease in elevated cholesterol and triglyceride levels in both types of diabetic rats. In 3T3-L1 adipocytes, chromium picolinate (0-10 micromol) per se did not produce any effect, however, when co-incubated with insulin it significantly increased the intracellular triglyceride synthesis (EC50 = 363.7nmol/1). Similarly in C2C12 myoblasts, chromium picolinate alone did not produce any effect, however, it significantly increased insulin-induced transport of 14C-glucose. In conclusion, chromium picolinate significantly improves deranged carbohydrate and lipid metabolism of experimental chemically induced diabetes in rats. The mechanism of in vivo anti-diabetic action appears to be peripheral (skeletal muscle and adipose tissue) insulin enhancing action of chromium.

3T3 Cells↗
PubMed2003

Effect of chromium on apolipoprotein A-I expression in HepG2 cells.

OBJECTIVE: Chromium is a key micronutrient required for lipid and carbohydrate metabolism. Some but not all clinical trials have associated use of chromium supplements with improved insulin sensitivity and lipid profile including increased high-density lipoprotein cholesterol levels. METHODS: Because apolipoprotein A-I (apoA-I) is the principal protein of high-density lipoprotein, the molecular pathways underlying chromium-related changes in apoA-I expression were studied in a human hepatoma cell line (HepG2) transfected with full-length apoA-I promoter attached to the reporter chloramphenicol acetyl transferase gene. RESULTS: Exposure of these cells to different concentrations of chromium chloride (0, 0.5, 1.0, and 3.0 mM) resulted in a dose-dependent decrease in apoA-I promoter activity (chloramphenicol acetyl transferase activity expressed as a percentage of an internal control was 99.4 +/- 7.2% in control cells versus 87.6 +/- 5.0%, 73.4 +/- 2.3%, and 36.6 +/- 3.9%, respectively, P < 0.01). Chromium chloride at 10 mM concentration was toxic and caused death in a large number of cells. Treating HepG2 cells with other minerals known to have insulin-sensitizing effects such as magnesium (1 mM), zinc (0.2 mM), and vanadyl sulfate (0.1 mM) significantly reduced apoA-I promoter activity in the presence and absence of 100 microU/mL of insulin. Northern blot analyses showed that the apoA-I mRNA content of cells treated with 0.2 mM of chromium chloride relative to G3PDH mRNA was not significantly increased compared with controls (0.652 +/- 0.122 versus 0.745 +/- 0.143, the ratio of apoA-I to glyceraldehyde 3-phosphate dehydrogenase (G3PDH) mRNA in control and chromium-treated cells, respectively). Western blot analyses of proteins secreted in culture media indicated that neither chromium treatment of the HepG2 cells (858.0 +/- 151.4 arbitrary units) nor treatment with magnesium (1323.3 +/- 175.7) or vanadium (1102 +/- 78.7) significantly altered apoA-I concentrations compared with controls (1061.7 +/- 114.7). However treatment of HepG2 cells with 0.2 mM of zinc significantly reduced apoA-I concentrations (291.0 +/- 29.2 versus 1061.7 +/- 114.7; P < 0.001). CONCLUSIONS: Supraphysiologic concentrations of chromium and other minerals with known insulin-sensitizing activity may reduce apoA-I promoter activity in cultured cells. Whether similar changes may occur in vivo remains to be shown. However, these observations do not support the use of pharmacologic amounts of chromium supplementation to enhance the cardioprotective lipid profile.

Antioxidants↗
PubMed2002

Speciation of aqueous chromium by use of solid-phase extractions in the field.

Here the fate and mobility of chromium in an organic-rich wetland area was studied through a field investigation in which chromium speciation in aqueous samples was estimated by use of solid-phase extraction resins that removed the cationic, anionic, and hydrophobic organic species from solution. Results show that aqueous chromium concentrations in the surface and pore waters at this site are higher than would be predicted by simple thermodynamic equilibrium with solid chromium hydroxides. Hexavalent chromium was not observed and therefore could not explain these higher than expected chromium concentrations. Aqueous chromium in concentrations greater than 30 microg/L was found to be slightly correlated with total dissolved organic carbon (R2 = 0.66), thus suggesting enhanced chromium concentrations because of complexation with organic ligands. The results of the solid-phase extraction performed show that aqueous chromium in the wetland pore water and surface water exists primarily as an anion (96%). It is concluded that the solubility and mobility of chromium are controlled, at least in part, by complexation with dissolved organic carbon and that this may be a thermodynamically controlled process.

Carbon↗
PubMed1999

Effects of niacin-bound chromium supplementation on body composition in overweight African-American women.

AIM: This pilot study was designed to determine whether 600 microg niacin-bound chromium ingested daily over 2 months by African-American women undergoing a modest dietary and exercise regimen influences weight loss and body composition. METHODS: Twenty overweight African-American women, engaged in a modest diet-exercise regimen, participated in a randomized, double-blinded, placebo-controlled, crossover study. They received placebo three times a day (t.i.d.) during the control period and niacin-bound chromium, 200 microg t.i.d., during the verum period. Control and verum periods were each 2 months in duration. One-half received placebo first (group 1), the other half received chromium first (group 2). Body weights (b.w.) and blood chemistries were measured by routine clinical methodology. Fat and nonfat body masses were estimated using bioelectrical impedance (electrolipography). RESULTS: In the first group of 10 women receiving niacin-bound chromium after the placebo period (group 1), b.w. loss was essentially the same, but fat loss was significantly greater and non-fat body mass loss significantly less with chromium intake. In contrast to the previous findings, there was a significantly greater loss of fat in the placebo compared to the verum period in the second group of eight women who received chromium first (group 2). Blood chemistries were not affected by intake of chromium for 2 months. CONCLUSIONS: Niacin-bound chromium given to modestly dieting-exercising African-American women caused a significant loss of fat and sparing of muscle compared to placebo. Once chromium was given at these dose levels, there was a 'carry-over' effect. Blood chemistries revealed no significant adverse effects from the ingestion of 600 microg of niacin-bound chromium daily over 2 months.

Adipose Tissue↗
PubMedDate not supplied

Chromium in biological samples from low-level exposed stainless steel and mild steel welders.

Occupational exposure to hexavalent chromium is of concern because of the carcinogenic action of this metal. The purpose of this study was to evaluate internal exposure to chromium in welders who were exposed to low levels of chromium. Chromium in urine, blood, and seminal fluid was determined among 60 welders and 45 referents. The concentration of chromium in urine and blood did not change across a workshift or across a 3-wk break in exposure. However, stainless-steel and mild-steel welders who were exposed to low levels of chromium and steel welders who were mildly exposed had significantly increased levels of chromium in post-shift urine (mean 2.1 nmol/mmol creatinine [standard deviation (SD) = 1.0] and 1.3 nmol/mmol creatinine [SD = 0.5], respectively) compared with referents (mean 0.7 nmol/mmol creatinine [SD = 0.3]). Pre-shift blood chromium concentrations showed a similar variation between exposed workers and referents. Subgroups of stainless-steel welders had very high levels of chromium in seminal fluid. This finding may, however, be explained by nonoccupational factors and, therefore, warrants further study. Attention should focus on the potential risk of delayed health effects among stainless-steel and mild-steel welders who heretofore were not thought to be at risk from chromium exposure.

Chromium↗
PubMed1997

Ingestion of chromium(VI) in drinking water by human volunteers: absorption, distribution, and excretion of single and repeated doses.

This study examines the magnitude of hexavalent chromium [Cr(VI)] absorption, distribution, and excretion following oral exposure to 5 and 10 mg Cr(VI)/L in drinking water administered as a single bolus dose (0.5 L swallowed in 2 min) or for 3 d at a dosage of 1 L/d (3 doses of 0.33 L each day, at 6-h intervals). Adult male volunteers ingested deionized water containing various concentrations of potassium chromate, and samples of urine, plasma, and red blood cells (RBCs) were collected and analyzed for total chromium throughout the studies. In the bolus dose studies, a fairly consistent pattern of urinary chromium excretion was observed, with an average half life of about 39 h. However, 4-d total urinary chromium excretion and peak concentrations in urine and blood varied considerably among the 5 volunteers. Studies of repeated exposure to smaller volumes ingested at a more gradual rate (i.e., 0.33 L over 5-15 min) showed similar urinary chromium excretion patterns but generally lower chromium uptake/excretion. Given that sustained elevations in RBC chromium levels provide a specific indication of chromium absorption in the hexavalent state, these data suggest that virtually all (> 99.7%) of the ingested Cr(VI) at 5 and 10 mg Cr(VI)/L was reduced to Cr(III) before entering the blood-stream. The interindividual differences in total chromium uptake and excretion are plausibly explained by ingestion of appreciable doses on an empty stomach, which likely results in the formation of well-absorbed Cr(III) organic complexes in gastrointestinal tissues and possibly the blood. The lack of any clinical indications of toxicity in the volunteers and the patterns of blood uptake and urinary excretion of chromium are consistent with a predominant uptake of Cr(III) organic complexes [derived from Cr(VI)] that are excreted more slowly than inorganic forms of Cr(III). Therefore, it appears that the endogenous reducing agents within the upper gastrointestinal tract and the blood provide sufficient reducing potential to prevent any substantial systemic uptake of Cr(VI) following drinking-water exposures at 5-10 mg Cr(VI)/L. Based on these data, the chemical environment in the gastrointestinal tract and the blood is effective even under relative fasting conditions in reducing Cr(VI) to one or more forms of Cr(III).

Absorption↗
PubMed2006

Chromium content in different kinds of Spanish infant formulae and estimation of dietary intake by infants fed on reconstituted powder formulae.

Chromium is well documented as an essential element for humans. Trivalent chromium, the main chemical form found in foods, is essential for maintaining normal glucose metabolism. Owing to analytical difficulties, several literature reports of chromium content of foods, especially for the lower levels, show large variability and should be interpreted with caution. Zeeman background correction, transversely heated graphite furnace atomic absorption spectrometry was used to determine the chromium content of 104 different infant formulae (cow's milk and soy protein based) marketed in Spain following an acid-digestion sample preparation procedure in a closed, pressurized and microwave digestion unit. The mean and range of chromium values, regarding types and main protein-based infant formulae are presented. Additionally, the influence of the type of container used, the impact of industrial process from different manufacturers and the physical state (powder and liquid formulae) on chromium levels is also discussed. In general, the infant formulae contain a higher chromium concentration than that found in human milk (reference range: 0.20-8.18 microg l-1), particularly in the case of hypoallergenic (18.16 +/- 7.89 microg l-1), lactose-free (11.37 +/- 3.07 microg l-1), pre-term (11.48 +/- 3.15 microg l-1) and soya (10.43 +/- 4.05 microg l-1) formulae. The maximum theoretical estimated intake of infants fed on the studied formulae was lower than the upper limit safety for trivalent chromium of 1 mg kg-1 (14 microg kg-1 b.w. day-1) recommended by the experts of Council for Responsible Nutrition (Hathcock 2004; available at: http://crnusa.org/safety.html), amounting to about 10, 15-18 and 26% of the standard (adapted and follow-up) and toddler, soya, lactose-free and pre-term, and hypoallergenic formulae, respectively. Therefore, manufacturers are called upon to make continued efforts to routinely monitor chromium levels, particularly for specialised and pre-term formulae, and at the same time, might consider the inclusion of labelling the levels of chromium at least in these complex formulations.

Animals↗
PubMed1978

Urinary chromium excretion, diurnal changes, and relationship to creatinine excretion in healthy and sick individuals of different ages.

Since urine is the main excretory pathway for chromium, this study was conducted to compare in normal individuals the daily urinary chromium excretion with a 4 hr sample, to investigate diurnal fluctuations of urinary chromium and age-dependent relationship between urinary chromium and creatinine excretion. The results can be summarized as 1) there was no significant difference between the observed 24 hr chromium excretion and 24 hr excretion calculated from the one 4 hr samples, 2) a diurnal variation was observed when urinary excretion was expressed as chromium per minute, but no time-related variation could be established when chromium/creatinine (Cr/Cre) ratios in samples from three different periods of the same day were compared, although a significant positive correlation existed between urinary chromium and creatinine concentration, 3) the Cr/Cre ratio was found to be age-dependent, 4) in malnourished children the Cr/Cre ratio was very high and significantly different from that of normal infants, 5) This ratio for the eight diabetics was found to be significantly higher when compared with normal adults. On the basis of these results, it is suggested that morning 4 hr urinary chromium reflects the daily chromium excretion and that the Cr/Cre ratio of single urine samples obtained during this period is a reliable criterion in the evaluation of chromium nutrition of individuals in different conditions, provided that the influence of age is taken into consideration.

Adolescent↗
PubMed1981

The effect of parity on maternal hair chromium concentration and the changes during pregnancy.

The effect of parity of maternal hair chromium and the changes during pregnancy were investigated. Hair samples were collected from nulliparous and multiparous women and longitudinally from pregnant women. Chromium was determined by flameless atomic absorption. Mean hair chromium in multiparous women was low when compared with nulliparous women of comparable ages. No significant decrease in hair chromium was observed between multiparous women and women who had borne only one child. Mean hair chromium in longitudinal samples was observed to decrease with advancing pregnancy. When initial hair chromium values were below 200 ng/g, the significant decrease occurred only in the 3rd trimester of pregnancy. These results show that 1) hair chromium in multiparous women is lower than that in nulliparous women, 2) depending on chromium nutrition, hair chromium of pregnant woman shows a decrease with advancing pregnancy, 3) if adequate amounts of chromium are not taken during pregnancy, deficiency may result with increasing parity.

Chromium↗