THE EXCRETION OF LARGE VITAMIN C LOADS IN YOUNG AND ELDERLY SUBJECTS: AN ASCORBIC ACID TOLERANCE TEST

1988 ◽  
Vol 17 (1) ◽  
pp. 35-41 ◽  
Author(s):  
R. J. NEALE ◽  
H. LIM ◽  
JULIE TURNER ◽  
C. FREEMAN ◽  
J. R. KEMM
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Acid Tolerance ◽  
Tolerance Test ◽  
Elderly Subjects ◽  
Young And Elderly Subjects

Clinical Usefulness of the Oral Ascorbic Acid Tolerance Test in Scurvy

1959 ◽  
Vol 7 (6) ◽  
pp. 630-633 ◽  
Author(s):  
JOSÉ E. DUTRA DE OLIVEIRA ◽  
WILLIAM N. PEARSON ◽  
WILLIAM J. DARBY
Keyword(s):  
Ascorbic Acid ◽  
Acid Tolerance ◽  
Tolerance Test ◽  
Clinical Usefulness

scholarly journals Antioxidant micronutrient supplementation increases erythrocyte membrane fluidity in adults from a rural Chinese community

2011 ◽  
Vol 106 (11) ◽  
pp. 1676-1682 ◽  
Author(s):  
Xiu-Xia Han ◽  
Ming Zhang ◽  
Ai-Guo Ma ◽  
Sheng Ge ◽  
Xue-Xiang Shi ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Membrane Fluidity ◽  
Elderly People ◽  
Erythrocyte Membrane ◽  
Elderly Subjects ◽  
Age Related ◽  
Erythrocyte Membrane Fluidity ◽  
Young And Elderly Subjects ◽  
Antioxidant Micronutrient ◽  
Β Carotene

The objective of the present study was to investigate age-related differences in erythrocyte membrane fluidity (EMF) and changes in antioxidant capacity following supplementation. A total of seventy-four children were randomly divided into two groups: group A1 was the placebo-controlled group and group A2 was supplemented daily with 600 μg retinol, 1·0 mg β-carotene, 100 mg tocopherol, 300 mg ascorbic acid and 200 μg Se. A total of ninety young people were randomly divided into B1 and B2 groups, and ninety-one elderly subjects were divided into C1 and C2 groups. Groups B1 and C1 were placebo-controlled groups, and groups B2 and C2 were daily supplemented with 900 μg retinol, 1·5 mg β-carotene, 200 mg tocopherol, 500 mg ascorbic acid and 400 μg Se. Results showed that plasma malondialdehyde (MDA) was 5·35 μmol/l in children, which was lower than in young and elderly people. The MDA levels of the young and elderly individuals in the treated groups were significantly lower compared with the control groups, but the supplementation did not alter MDA levels in children. At baseline, there was a lower value of polarisation (ρ) and microviscosity (η) in children, indicating a higher EMF, than in both the young and elderly subjects. After the 2-month trial, the ρ and η values of young and elderly subjects in the treated groups decreased significantly in comparison with the placebo groups, indicating an increase in EMF. In conclusion, there was a background of higher MDA levels and lower EMF in young and elderly people than in children, which could be improved by antioxidant supplementation.

No Effect on Serum Lipids by Moderate and High Doses of Vitamin C in Elderly Subjects with Low Plasma Ascorbic Acid Levels

1988 ◽  
Vol 32 (3) ◽  
pp. 133-137 ◽  
Author(s):  
Antti Aro ◽  
Martti Kyllästinen ◽  
Ella Kostiainen ◽  
Carl-Gustav Gref ◽  
Sirkka Elfving ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Serum Lipids ◽  
Elderly Subjects ◽  
Plasma Ascorbic Acid ◽  
High Doses

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

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