Thiamine, riboflavin, pyridoxine, and vitamin C status in premature infants receiving parenteral and enteral nutrition.

BACKGROUND: There is a paucity of data about water soluble vitamin status in low birthweight infants. Therefore, the authors' objective was to assess current feeding protocols. METHODS: The authors measured serum concentrations for riboflavin, pyridoxine, and vitamin C and functional assays for thiamine and riboflavin longitudinally in 16 premature infants (birthweight, 1,336 +/- 351 g; gestational age, 30 +/- 2.5 weeks) before receiving nutrition (time 1, 2 +/- 1 days), during supplemental or parenteral nutrition (time 2, 16 +/- 10 days) and while receiving full oral feedings (time 3, 32 +/- 15 days). In plasma, vitamin C was measured colorimetrically, and riboflavin and pyridoxine were measured using high-performance liquid chromatography. The erythrocyte transketolase test as a functional evaluation of thiamine and the erythrocyte glutathione reductase test for riboflavin were measured colorimetrically. RESULTS: At time 1, nutrient intake of vitamins were negligible because infants were receiving intravenous glucose and electrolytes only. Intakes differed between time 2 and time 3 for thiamine (510 +/- 280 and 254 +/- 115 microg. kg-1. d-1, respectively), riboflavin (624 +/- 305 and 371 +/- 193 microg. kg-1. d-1, respectively), and pyridoxine (394 +/- 243 and 173 +/- 85 microg/100 kcal, respectively), but not for vitamin C (32 +/- 17 and 28 +/- 12 mg. kg-1. d-1, respectively). Blood levels at times 1, 2, and 3 were for thiamine (4.9 +/- 2.7%, 3.3 +/- 6.6%, and 4.1 +/- 9% erythrocyte transketolase test, respectively), riboflavin (0.91 +/- 0.31, 0.7 +/- 0.3, 0.91 +/- 0.18 erythrocyte glutathione reductase test, respectively), riboflavin (19.5 +/- 17, 23.3 +/- 8.6, 17.6 +/- 10 ng/mL, respectively), pyridoxine (32 +/- 25, 40 +/- 16, 37 +/- 26 ng/mL, respectively), and vitamin C (5.2 +/- 3, 5 +/- 2.2, 10 +/- 5 microg/mL, respectively) and did not differ at those times. CONCLUSIONS: Current intakes of these vitamins, except for possibly vitamin C, during parenteral and enteral nutrition seem to result in adequate plasma concentrations and normal functional indices.

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.

Molybdenum requirements in low-birth-weight infants receiving parenteral and enteral nutrition.

BACKGROUND: Molybdenum (Mo) is an essential trace element required by three enzymatic systems, yet there are no reports of Mo deficiency in infants. Low-birth-weight infants (LBW) might be at risk for Mo deficiency because they are born before adequate stores for Mo can be acquired, they have rapid growth requiring increased intakes, and they frequently receive supplemental parenteral nutrition (SPN) and total parenteral nutrition (TPN) unsupplemented with molybdenum. METHODS: To investigate Mo requirements of LBW infants (n = 16; birth weight, 1336+/-351 g; gestational age, 29.8+/-2.5 weeks; M+/-SD), the authors collected all feeds, urine, and feces prior to TPN (baseline, n = 16, collections = 16), during TPN (n = 9, collections = 19), during SPN (n = 13, collections = 17), and after one week of full oral feeds (FOFs) of formula or human milk (FOF, n = 16, collections = 16). RESULTS: Infant weights at collection times were: 1.3+/-0.3 g, 1.27+/-0.4 g, 1.4+/-0.3 g, and 1.7+/-0.5 g, respectively. Mo intake was 0.03+/-0.1 microg/d, 0.34+/-0.1 microg/d, 1.25+/-1.7 microg/d, and 6.1+/-2.5 microg/d. Mo output was 0.64+/-0.6, 0.34+/-0.5, 0.68+/-0.8, and 4.1+/-2.5 microg/d. Mo balance at these times was -0.60+/-0.5, -0.001+/-0.5, 0.57+/-1.9, and 2.0+/-2.9 microg/d. Mo balance increased with time, yet some infants were always in negative balance, even though Mo intakes exceeded recommendations. CONCLUSIONS: The authors speculate that an intravenous intake of 1 microg/kg/d (10 nmol/kg/d) and an oral intake of 4-6 microg/kg/d (40-60 nmol/kg/d) would be adequate for the LBW infant.