Chromium in parenteral nutrition: too little or too much?

Although guidelines for routine parenteral supplements of chromium (Cr) were published, there remain major concerns about the infusion of excess Cr. In addition, little information is available on appropriate dosage for intravenous usage. Cr functions as a regulator of insulin action. In humans, the 3 reported cases of Cr deficiency developed peripheral neuropathy, weight loss, and hyperglycemia. Supplementation of Cr to the parenteral nutrition (PN) solution corrected these abnormalities. For parenteral Cr, concerns arise from the high levels found in sera (up to 40-fold higher) and tissues (10- to 100-fold higher) and their effects on kidneys: In 15 children receiving long-term PN, the glomerular filtration rate was lower than that of non-PN controls and was inversely correlated with Cr indices. Furthermore, in a randomized blinded prospective protocol involving 75 newborns, the group receiving the recommended dose of Cr showed higher levels of creatinine that were positively correlated with Cr intake. Of note, Cr contaminants in PN solutions can increase the amount delivered by 10%-100%. A possible method for estimating adequate Cr to be provided IV is to calculate the amount physiologically absorbed in healthy people. This amount is 10 to 100 times less than the daily recommended parenteral Cr in adults. The accumulated scientific data presented here point to a serious need to lower the recommended amount of parenteral Cr.