Human plasma patterns during 14 days ingestion of vitamin E, beta-carotene, ascorbic acid, and their various combinations.

OBJECTIVE

We wanted to learn about plasma patterns of ascorbic acid (AA), beta carotene (BC), and vitamin E (vit E) when each or their various combinations were fed to humans. Conceivably, the combined absorption of these antioxidants could synergize maximum plasma redox potential.

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 methods; values were compared with each group's baseline value.

RESULTS

AA feeding did not significantly increase already saturated plasma AA concentrations 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 addition, or a combination of BC and vit E significantly increased plasma vit E and carotene levels after 2 days. A statistically (ANOVA) significant increase in plasma vit E above baseline was noted when vit E was 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.

CONCLUSION

Our results show that BC or AA ingestion in combination with vit 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 AA, BC, vit E combination is ingested is not yet obvious.