Direct and indirect vitamin A supplementation strategies result in different plasma and tissue retinol kinetics in neonatal rats.
Many questions remain regarding vitamin A (VA) supplementation of infants. Herein we compared direct oral VA supplementation of the neonate and indirect treatment through maternal dietary VA (M-VA) treatment on VA status and kinetics in neonatal rats. Treatments included direct VA combined with retinoic acid (RA) [D-VARA; VA (6 mg/kg) + 10% RA, given orally to neonates on postnatal day (P)2 and P3] and indirect VA supplementation through increased M-VA, compared with each other and oil-treated neonates. [(3)H]retinol was administered orally to all neonates on P4. Plasma and tissue [(3)H]retinol kinetics were determined from 1 h to 14 days post-dosing. D-VARA versus placebo dramatically increased liver and lung retinol, but only in the first 8-10 days. In M-VA neonates, liver and lung VA increased progressively throughout the study. Compartmental modeling of plasma [(3)H]retinol showed that both D-VARA and indirect M-VA reduced retinol recycling between plasma and tissues. Compartmental models of individual tissues predicted that D-VARA stimulated the uptake of VA in chylomicrons to extrahepatic tissues, especially intestine, while the uptake was not observed in M-VA neonates. In conclusion, indirect maternal supplementation had a greater sustained effect than D-VARA on neonatal VA status, while also differentially affecting plasma and tissue retinol kinetics.
Department of Nutritional Sciences Pennsylvania State University, University Park, PA 16802.
Libo
L
Tan
Department of Nutritional Sciences Pennsylvania State University, University Park, PA 16802 Cardiometabolic Disease, Merck Research Laboratories, Boston, MA 02115.
Amanda E
AE
Babbs
Department of Nutritional Sciences Pennsylvania State University, University Park, PA 16802.
Michael H
MH
Green
Department of Nutritional Sciences Pennsylvania State University, University Park, PA 16802 Huck Institutes for the Life Sciences, Pennsylvania State University, University Park, PA 16802 acr6@psu.edu.
A Catharine
AC
Ross
D000284:Administration, Oral; D000818:Animals; D000831:Animals, Newborn; D019587:Dietary Supplements; D005260:Female; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D008892:Milk / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014801:Vitamin A / Q000008:administration & dosage* / Q000493:pharmacokinetics; D014815:Vitamins / Q000008:administration & dosage* / Q000493:pharmacokinetics
D014815:Vitamins; D014801:Vitamin A
WinSAAM; compartmental model; maternal dietary vitamin A; neonate