The iv lipid emulsion (LIP) is a source of oxidants, which may stimulate inflammation. Coadministration of parenteral multivitamins (MVP) with LIP prevents lipid peroxidation in light-exposed total parenteral nutrition (TPN). We hypothesized that this modality of TPN administration affects systemic inflammation, which may be modulated by exposure to oxygen. Premature infants were allocated to three TPN regimens: control regimen—MVP coadministered with amino acid/dextrose exposed to ambient light, LIP provided separately (n= 9)—LIP+ MVP light exposed (LE): MVP coadministered with light-exposed LIP (n= 9)—LIP+ MVP light protected (LP): MVP coadministered with light-protected LIP (n= 8). In LE and LP, amino acid/dextrose was provided separately. On reaching full TPN, infants were sampled for IL-6 and IL-8 in plasma and the redox potential of glutathione in whole blood (E, mV). Data were compared (ANOVA) in infants exposed to low (< 0.25) versus high (≥ 0.25) FiO 2. Patients (mean±SD: birth weight 797±172 g; GA 26±1 wk) had similar clinical characteristics in TPN groups. Cytokine levels correlated positively (p< 0.01) with FiO 2 and E. High FiO 2 stimulated an increase (p< 0.01) in cytokines in control regimen, whereas these markers remained unaffected by oxygen in the LE and LP groups. The choice of a TPN admixture may have important consequences on the systemic inflammatory response triggered by an oxidant stress.