TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1262. HEALTH EFFECTSblood, 96 µg/L in plasma, 0.44 µg/10 10 in lymphocytes, and 4,535.6 µg/g creatinine in urine. Fortreatment with chromium(VI) the levels were 233.2 µg/L for whole blood, 138 µg/L for plasma,2.87 µg/10 10 for lymphocytes, and 2,947.9 µg/g creatinine in urine. The levels in lymphocytes in thechromium(III) treated animals were no different than in untreated animals. However, for chromium(VI)the lymphocyte levels were about 6-fold higher than control values. After 72 hours, the chromium levelswere significantly reduced. These results suggest that absorbed chromium(III) compounds may beexcreted more rapidly than absorbed chromium(VI) compounds because of a poorer ability to enter cells.2.3.1.2 Oral ExposureChromium(III) is an essential nutrient required for normal energy metabolism. The National ResearchCouncil recommends a dietary intake of 50–200 µg/day (NRC 1989). The biologically active form is anunidentified organic complex of chromium(III) often referred to as GTF. Chromium(III) picolinate is acommon form of chromium(III) nutritional supplementation.Approximately 0.5–2.0% of dietary chromium(III) is absorbed via the gastrointestinal tract of humans(Anderson et al. 1983; Anderson 1986) as inferred from urinary excretion measurements. The absorptionefficiency is dependent on the dietary intake. At low levels of dietary intake (10 µg), .2.0% of thechromium is absorbed. When intake is increased by supplementation to $40 µg, the absorption efficiencydrops to .0.5% (Anderson et al. 1983; Anderson 1986). Although Mertz (1969) reported that somechromium(III) complexes are absorbed at 25%, this has not been corroborated by other studies (Anderson1981).The bioavailability of chromium(III) was determined in 8 healthy adults who were administered 400 µgchromium(III)/day as chromium picolinate for 3 consecutive days by Gargas et al. (1994). The meanabsorption of chromium was 2.8%±1.4 % (standard deviation).Urinary excretion data from 15 female and 27 male subjects given 200 µg chromium(III) as chromiumtrichloride indicated that gastrointestinal absorption was at least 0.4% (Anderson et al. 1983). Netabsorption of chromium(III) by a group of 23 elderly subjects who received an average of 24.5 µg/day(0.00035 mg chromium(III)/kg/day) from their normal diets was calculated to be 0.6 µgchromium(III)/day, based on an excretion of 0.4 µg chromium/day in the urine and 23.9 µg chromium/day in the feces, with a net retention of 0.2 µg/day. Thus about 2.4% was absorbed. The retention wasconsidered adequate for their requirements (Bunker et al. 1984).