Kinetics of plasma 13C-CDCA clearance measured between days 11–14 in preterm piglets given treatment of PN plus the following: Intralipid (IL), Intralipid plus vitamin E (ILE), Omegaven (OV), or Omegaven plus phytosterols (PS). Values are means ± SEM; n = 8–10 pigs/group. *P < .05 vs IL. Panel A shows time-dependent changes in 13C-CDCA enrichment expressed as natural log of mole percentage excess (Ln mpe) during the 72-hour period; panels B and C show the parameters of whole-body half-life and mean retention time of 13C-CDCA calculated as described in the “Statistics” section. PN, parenteral nutrition; SEM, standard error of the mean.