Nanoparticles of chromium picolinate enhance chromium digestibility and absorption

BACKGROUND: Trivalent chromium (Cr) is a trace element that is difficult to digest and absorb. The objective of this study was to determine whether reducing organic Cr to nanometre size would increase its digestibility. RESULTS: Forty-eight 8-week-old female Sprague-Dawley rats were randomly assigned to one of four dietary treatments: (1) basal diet (control); (2) basal diet plus 300 mu g kg(-1) Cr as chromium chloride (CrCl3); (3) basal diet plus 300 mu g kg(-1) Cr as chromium picolinate (Crpic); (4) basal diet plus 300 mu g kg(-1) Cr as nanoparticulate Crpic (nanoCrpic). NanoCrpic was prepared from Crpic with a particle size of 55-100 nm. The experiment lasted 48 days. Cr digestibility and serum Cr concentration were 1.66 and 1.96 times greater respectively in rats fed nanoCrpic than in rats fed Crpic (P < 0.05). The average daily gain was greater in rats fed nanoCrpic or Crpic than in control rats (P < 0.05). The high-density lipoprotein content increased while the very-low-density plus low-density lipoprotein content decreased in rats fed nanoCrpic as compared with rats fed Crpic or CrCl3 (P < 0.05). CONCLUSION: This study indicates that reducing the particle size of Crpic enhances Cr digestibility and absorption in rats and alters some blood metabolite concentrations. (C) 2009 Society of Chemical Industry