title: Sulfur balances in intravenously fed infants: effects of cysteine supplementation.
abstract: Sulfur balances were completed in newborn infants parenterally fed with or without cysteine. In both groups, the preservative, potassium metabisulfite, accounted for the majority of sulfur intake (32 mg S/kg/day), while methionine intakes provided an additional 27 sulfate losses accounted for approximately 95% of the sulfur excretion, with the remainder contained in amino acids. Balance data accounted for over 99% of the sulfur infused in the unsupplemented group, but only 90% of that given to the cysteine-supplemented group. Thus, urinary excretion of sulfate generally reflects input from either inorganic or amino acid sources. Of the sulfur retained in the supplemented group, 75% was calculated to be retained in lean tissue and in increases in total body sulfate, but the distribution of the remaining 25% remains unknown. The failure to account fully for the sulfate provided to the cysteine-supplemented group, however, may be due to errors in the balance technique or due to an accumulation of cysteine or sulfate in body pools undefined by this study.
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage; D003545:Cysteine / Q000008:administration & dosage*; D002149:Energy Intake; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D009584:Nitrogen / Q000378:metabolism; D010288:Parenteral Nutrition; D013431:Sulfates / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism* / Q000652:urine
chemical_list: D000596:Amino Acids; D013431:Sulfates; D013455:Sulfur; D003545:Cysteine; D009584:Nitrogen