Lactating sows and suckling piglets preferentially incorporate RRR- over all-rac-alpha-tocopherol into milk, plasma and tissues.
Synthetic vitamin E, all-rac-alpha-tocopherol, contains eight different stereoisomers, only one of which, RRR-alpha-tocopherol, occurs naturally. The objective of this investigation was to evaluate the relative abilities of these two vitamin E forms to enrich piglet tissues when fed as alpha-tocopheryl acetates to sows during pregnancy and lactation. alpha-Tocopherol delivery to fetuses and to suckling piglets was monitored by feeding 150 mg each of d(3)-RRR-alpha- and d(6)-all-rac-alpha-tocopheryl acetate to three pregnant sows daily from 7 d before to 7 d after giving birth. Labeled and unlabeled vitamin E concentration ratios were measured in sow plasma and milk, and in piglet (n = 9) plasma and tissues at birth, 7 and 21 d. At birth, despite elevated sow plasma deuterated alpha-tocopherol concentrations, no labeled alpha-tocopherol was detected in piglet plasma or tissues. Sow plasma and milk d(3)-alpha- to d(6)-alpha-tocopherol concentrations were 2:1, leading to a 2:1 ratio in suckling piglet plasma and tissues. In piglets at d 7 compared with birth, most tissues contained a 10-fold increase in total alpha-tocopherol; the highest deuterated vitamin E concentrations were in the liver, followed by the lung, heart, kidney, muscle, intestine and brain. In conclusion, pigs discriminate between RRR- and all-rac-alpha-tocopherol with a preference for RRR-alpha-tocopherol; thus, the official bioequivalence ratio of 1.36:1 RRR- to all-rac-alpha-tocopherol is underestimated. After initiation of suckling, piglet plasma and tissues demonstrated a dramatic increase in vitamin E concentrations, emphasizing the limited placental vitamin E transfer and the importance of milk for enhancing the vitamin E status of the newborn.
Lauridsen
Charlotte
C
Department of Animal Nutrition and Physiology, Research Centre Foulum, DK-8830 Tjele, Denmark. charlotte.lauridsen@agrsci.dk
Engel
Harold
H
Jensen
Søren K
SK
Craig
A Morrie
AM
Traber
Maret G
MG
D000818:Animals; D000833:Animals, Suckling / Q000378:metabolism*; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics*; D003903:Deuterium; D005260:Female; D007700:Kinetics; D007774:Lactation / Q000378:metabolism / Q000502:physiology; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008892:Milk / Q000737:chemistry; D009928:Organ Specificity; D011247:Pregnancy; D013237:Stereoisomerism; D013552:Swine / Q000378:metabolism / Q000502:physiology*; D014018:Tissue Distribution; D024505:Tocopherols / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics*; D024502:alpha-Tocopherol / Q000032:analysis / Q000737:chemistry / Q000493:pharmacokinetics
D000975:Antioxidants; D003903:Deuterium; D024502:alpha-Tocopherol; D024505:Tocopherols