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.
Friel
J K
JK
Department of Biochemistry, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X9, Canada. jfriel@morgan.ucs.mun.ca
Bessie
J C
JC
Belkhode
S L
SL
Edgecombe
C
C
Steele-Rodway
M
M
Downton
G
G
Kwa
P G
PG
Aziz
K
K
D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003124:Colorimetry / Q000379:methods; D004750:Enteral Nutrition; D005260:Female; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight / Q000097:blood*; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood; D008297:Male; D009751:Nutritional Requirements; D009752:Nutritional Status; D010288:Parenteral Nutrition; D011736:Pyridoxine / Q000008:administration & dosage / Q000097:blood; D012256:Riboflavin / Q000008:administration & dosage / Q000097:blood; D013831:Thiamine / Q000008:administration & dosage / Q000097:blood
D011736:Pyridoxine; D001205:Ascorbic Acid; D012256:Riboflavin; D013831:Thiamine