Relationship in humans between ascorbic acid consumption and levels of total and reduced ascorbic acid in lens, aqueous humor, and plasma.
The relationships between plasma, aqueous humor and lens ascorbic acid levels are examined in 131 samples from 127 patients. Mean ascorbate intake for nonsupplemented individuals was 148 mg/day or over two times the recommended daily allowance. A subset of 44 patients participated in a trial to assess the impact of vitamin C supplementation of 2 grams per day on aqueous and lens ascorbic acid levels. Such supplementation significantly increased both total and reduced ascorbic acid levels in plasma and aqueous and total ascorbic acid in the lens. Correlation coefficients relating total and reduced ascorbic acid levels in the three tissues ranged from 0.42 to 0.19 (p less than 0.05 for all correlation coefficients). Over 60% of the ascorbate was present in the reduced form in plasma and aqueous, and about 50% of the lens ascorbate was in the reduced form.
Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA.
A
A
Taylor
P F
PF
Jacques
D
D
Nadler
F
F
Morrow
S I
SI
Sulsky
D
D
Shepard
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001082:Aqueous Humor / Q000737:chemistry*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000032:analysis*; D002387:Cataract Extraction; D004032:Diet; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000737:chemistry*; D008297:Male; D008875:Middle Aged
D001205:Ascorbic Acid