H. Baker et al., HUMAN PLASMA PATTERNS DURING 14 DAYS INGESTION OF VITAMIN-E, BETA-CAROTENE, ASCORBIC-ACID, AND THEIR VARIOUS COMBINATIONS, Journal of the American College of Nutrition, 15(2), 1996, pp. 159-163
Objective: We wanted to learn about plasma patterns of ascorbic acid (
AA), beta carotene (BC), and vitamin E (vit E) when each or their vari
ous combinations were fed to humans. Conceivably, the combined absorpt
ion of these antioxidants could synergize maximum plasma redox potenti
al. Methods: Vit E (800 mg/day), BC (30 mg/day), and AA (1000 mg/day)
were fed individually or in various combinations with each other to 91
volunteers divided into different feeding groups for 14 days. Plasma
vit E, carotenes, and AA patterns were analyzed by standardized method
s; values were compared with each group's baseline value. Results: AA
feeding did not significantly increase already saturated plasma AA con
centrations above baseline. Intake of BC did not influence vitamin A (
vit A) levels. Feeding of only vit E or only BC, with or without AA ad
dition, or a combination of BC and vit E significantly increased plasm
a vit E and carotene levels after 2 days. A statistically (ANOVA) sign
ificant increase in plasma vit E above baseline was noted when vit E w
as ingested combined with AA or BC; this increase in plasma vit E was
not significant when AA, BC and vit E were taken in combination. Concl
usion: Our results show that BC or AA ingestion in combination with vi
t E significantly increases circulating vit E above that seen when vit
E is individually ingested. Vit E in combination with BC or AA seems
a practical means or increasing the circulating antioxidant potential
afforded by vit E. Reasons why such synergism does not exist when an A
A, BC, vit E combination is ingested is not yet obvious.