A comparison of the metabolism of eighteen-carbon 13C-unsaturated fatty acids in healthy women.

Altered use of different dietary fatty acids may contribute to several chronic diseases, including obesity, noninsulin-dependent diabetes mellitus, and cardiovascular disease. However, few comparative data are available to support this link, so the goal of the present study was to compare the metabolism of [(13)C]oleate, [(13)C]alpha-linolenate, [(13)C]elaidate, and [(13)C]linoleate through oxidation and incorporation into plasma lipid fractions and adipose tissue. Each tracer was given as a single oral bolus to six healthy women. Samples were collected over 8 days, and (13)C was analyzed using isotope ratio mass spectrometry. At 9 h postdose, cumulative oxidation was similar for [(13)C]elaidate, [(13)C]oleate, and [(13)C]alpha-linolenate (19 +/- 1%, 20 +/- 4%, and 19 +/- 3% dose, respectively). Significantly lower oxidation of [(13)C]linoleate (12 +/- 4% dose; P < 0.05) was accompanied by its higher incorporation into plasma phospholipids and cholesteryl esters. Abdominal adipose tissue was enriched with [(13)C]alpha-linolenate, [(13)C]elaidate, or [(13)C]linoleate within 6 h. The percentage linoleate in plasma phospholipids correlated positively with [(13)C]linoleate and [(13)C]elaidate oxidation, indicating a potential role of background diet. Conversion of [(13)C]linoleate and [(13)C]alpha-linolenate to longer chain polyunsaturates was a quantitatively minor route of utilization.

Eighteen-month follow-up of infants fed evaporated milk formula.

In parts of Canada including Newfoundland and Labrador and among Aboriginal peoples, infants still consume evaporated milk (EM) formulas for cultural and economic reasons. At 3 and 6 months, full-term infants fed EM (n = 30) received low intakes of iron, thiamine, selenium and had higher weight velocity than breastfed (BF, n = 29) infants. EM infants had greater anemia, lowered transketolase activity (thiamine) and lowered glutathione peroxidase (selenium) activity (p < 0.05). To determine the later effect of early feeding deficit on nutritional status, we examined these same infants at 18 months of age. At that time, there were no differences in dietary intakes of energy, protein, zinc, copper, selenium and iron, nor in plasma levels of zinc, copper, vitamin C, nor in red blood cell activity levels of glutathione reductase (riboflavin), transketolase, glutathione peroxidase, nor in superoxide dismutase. However, EM infants weighed more and were more likely to visit a physician, have anemia, and have iron depletion than were BF infants. We conclude that infants consuming evaporated milk formulas should receive iron supplements throughout infancy.

Evaluation of full-term infants fed an evaporated milk formula.

The objective of this prospective, cohort study was to compare the nutritional status of full-term infants who were fed human milk (BF, n = 29), formula (FF, n = 30) or evaporated milk formulae (EM, n = 30) for at least 3 months. Infants were seen at enrollment, 3 and 6 months, at which times a blood sample, diet record and anthropometric data were collected. Infants in the EM group received solids earlier (12 +/- 5 weeks) than did FF infants (15 +/- 4 weeks), and both were earlier than BF infants (19 +/- 4 weeks). Only 26% of the EM fed group received iron supplements as ferrous sulphate drops. Seven BF, 12 FF and 20 EM had abnormal ferritin values (< 10 ng ml-1) at 6 months. Copper intake was lower in the EM infants at 3 and 6 months. However, plasma copper and erythrocyte copper zinc superoxide dismutase (ZnCuSOD) levels did not differ between groups. Selenium intake was lower in the EM group (5 +/- 1 and 10 +/- 5 micrograms d-1; 3 and 6 months) than in the FF infants (13 +/- 4 and 19 +/- 7 micrograms d-1; 3 and 6 months). Erythrocyte SeGHSPx levels in EM infants were lower at 6 months (EM, 33.2 +/- 3.4; FF. 35.2 +/- 3.9: BF, 36.1 +/- 3.8 mU mg Hb-1). Thiamin intake (0.99 +/- 0.08 and 1.24 +/- 0.32; 3 and 6 months, mg 1000 kcal-1) was higher in the FF group than in EM infants (0.38 +/- 0.39 and 0.66 +/- 0.38; 3 and 6 months). There were more (13%) abnormal thiamin assays in the EM group at 6 months than in the BF and FF infants (0%). In conclusion, infants fed evaporated milk formula receive adequate copper but may not receive enough thiamin or selenium. Unless supplemented from birth with medicinal iron, intakes of iron will be inadequate.

Intravenous iron administration to very-low-birth-weight newborns receiving total and partial parenteral nutrition.

BACKGROUND: Intravenous iron supplements are not routinely administered to very-low-birth-weight newborns receiving total parenteral nutrition because of the possible increased risk of infection and because iron needs may be met with blood transfusions. METHODS: To assess the benefits of a prudent IV iron supplement (200 to 250 micrograms/kg/d), 26 very-low-birth-weight newborns (birth weight, 1005 +/- 302 g; gestational age, 28 +/- 2.3 weeks; mean +/- SD) were randomly allocated to receive total parenteral nutrition without iron (No-Iron) or with iron supplied as iron dextran (Iron). These newborns were followed at baseline (2 to 3 days after birth) and at weeks 1 to 4 thereafter. At each sampling time, urine samples, fecal samples (rarely), unused total parenteral nutrition solutions, blood products, and a blood sample (1 mL) were collected. RESULTS: There were no differences between the two groups in anthropometric measurements, hematologic or biochemical parameters, number or amount of blood transfusions (2.3 +/- 1.9), amount of blood removed for diagnostic purposes (44 +/- 16 mL), or number of septic events (n = 16). There was no difference between the groups for the total iron excreted; however, the Iron group retained more iron. Iron balance was negative for all but 10 newborns (No-Iron, 3; Iron, 7) throughout the study. CONCLUSIONS: A total iron intake of 400 micrograms/kg/d, half of which was provided by IV iron, is not sufficient to maintain iron balance or to meet fetal accretion rates (1000 micrograms/kg/d) in very-low-birth-weight newborns receiving total parenteral nutrition. Furthermore, endogenous iron from blood transfusions does not provide an adequate supply of iron.