Chromium adequate intake

Chromium is a trivalent cption that occurs as A typical daily intake isO-5 3-8 jimoJ (25-200 ig/day). After absorption from the diet, chromium occurs bound to transferrin. A safe and adequate intake of 50 to 200 ffg Cr/day has been established. Chromium appears to participate in glucose metabolism. The ion may play a part in mediating the hormonal effects of insulin. Chromium deficiency results in abnormally high glucose tolerance curves and impaired clearance of plasma glucose. Chromium deficiency can be induced in animals. There is evidence that... 

Chromium (III), on the other hand, is an essential trace metal in mammalian nutrition, aiding in the metabolism of glucose see Nutritional Aspects of Metals Trace Element. The adequate intake of chromium has been estimated as 25-35pgday The glucose tolerance factor (GTF) is a chromium containing extract of brewer s yeast, which enhances the action of insulin. There is no evidence for any toxic effects of Cr. ... 

Many studies report beneficial effects of trivalent chromium. The element is described by WHO [24.5] as essential owing to its ability to strengthen the activity of in-suHn and its influence on carbohydrate and Upid metaboHsm. Biological systems commonly contain chromium as Cr in small concentrations [24.6]. It is thought, but disputed, that chromium is essential for life and involved in human glucose metaboHsm [24.7]. Chromium intake has been shown to be positive for humans and decreases the symptoms of diabetes in people with glucose intolerance [24.8]. An adequate intake of chromium for an adult is 50-200 pg/day and the content of chromium in tissues is 100-1000 pg/kg dry weight. 

Daily urinary excretion levels of chromium were nearly identical in men and women (averages of 0.17 and 0.20 pg/L, respectively 0.18 pg/L combined) who ate normal dietary levels of chromium ( 60 pg chromium(III)/day). When the subjects normal diets were supplemented with 200 pg chromium(in)/day as chromium trichloride to provide intakes of 260 pg chromium(ni)/day, urinary excretion of chromium rose proportionately to an average of 0.98 pg/L combined. Thus a five-fold increase in oral intake resulted in about a five-fold increase in excretion, indicating absorption was proportional to the dose regardless of whether the source was food or supplement (Anderson et al. 1983). A group of 23 elderly subjects who received an average of 24.5 pg/day (0.00035 mg chromium(III)/kg/day) from their normal diets excreted 0.4 pg chromium/day in the urine (1.6%) and 23.9 pg chromium/day in the feces (97.6%), with a net retention of 0.2 pg/day (0.8%). Based on the 1980 daily requirement for absorbable chromium of 1 pg/day by the National Academy of Science Food and Nutrition Board, the retention was considered adequate for their requirements (Bunker et al. 1984). 

No MRLs were derived for oral exposure to chromium(VI) or chromium(III). The available data on reproductive and developmental effects are insufficient or too contradictory to establish acute-, intermediate-, or chronic-duration oral NOAELs or LOAELs which are both used in the uncertainty factor approach to derive MRL values. However, the upper range of the estimated safe and adequate daily dietary intake (ESADDI) of 200 pg chromium/day (0.003 mg/kg/day for a 70 kg individual) (NRC 1989) has been adopted as provisional guidance for oral exposure to chromium(VI) and chromium(in). This guidance is necessary because of the prevalence of chromium at hazardous waste sites, the fairly complete database, and the fact that chromium is an essential nutrient. 

Chromium(III) is an essential nutrient required for maintaining normal glucose metabolism. The NRC established estimated safe and adequate daily dietary intakes (ESADDIs) of 10-80 pg/day for children aged 1-3 years 30-120 pg/day for children aged 4-6 years, and 50-200 pg/day for children aged 7 years or older (NRC 1989). These recommendations were derived by extrapolating the adult ESADDI value of 50-200 pg/day on the basis of expected food intake. 

O Flaherty EJ (1994) Comparison of rference dose with estimated safe and adequate daily dietary intake for chromium. In Mertz W and Abernathy CO, eds. Risk Assessment of Essential Elements, pp. 213—218. ILSl Press, Washington, DC. 

Only very small amounts of chromium are required. The estimated safe and adequate adult daily dietary intake is 50-200//g/day (National Research Council 1989). Below intakes of about 40//g/day, fractional oral absorption of chromium increases as intake is decreased (Anderson and Kozlovsky 1985). Biologically active Cr(III) may be more efficiently absorbed from the gastrointestinal tract than other forms of soluble chromium (Mertz and Roginski 1971). 

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