THE IMPORTANCE OF VITAMIN-C FOR HYDROXYLATION OF VITAMIN-D3 TO 1,25(OH)2D3 IN MAN

被引：9
作者：
CANTATORE, FP
LOPERFIDO, MC
MAGLI, DM
MANCINI, L
CARROZZO, M
机构：
[1] Department of Rheumatology, University of Bari, Bari
来源：
CLINICAL RHEUMATOLOGY | 1991年 / 10卷 / 02期
关键词：
ASCORBIC ACID; VITAMIN-D;
D O I：
10.1007/BF02207657
中图分类号：
R5 [内科学];
学科分类号：
1002 ; 100201 ;
摘要：
The effects of vitamin C on 1,25(OH)2D3 synthesis in humans were evaluated; the study included 20 females. They were divided into 2 groups. The first of the 10 subjects (age range 55-71) received ascorbic acid at a dose of 150 mg/die i.v. for 10 days; the second 10 subjects (age range 55-69) received a placebo i.v. for 10 days. In a later study (after a 30-day washout) the same two groups were tested for the second time with ascorbic acid at a dose of 1,000 mg/die i.v. for 10 days and placebo i.v. for 10 days. Serum calcium and phosphorus, serum Ca + +, serum proteins, blood and urinary pH, serum 25(OH)D3 and 1,25(OH)2D3, serum PTH, urinary hydroxyprolin were tested before and after the treatments. In the first study a significant increase in serum 1,25(OH)2D3 was observed after ascorbic acid while no significant variation was observed for the other parameters. In the second study, a significant increase in serum Ca + + and a significant decrease in serum 1,25(OH)2D3 were observed after ascorbic acid while no significant variation was observed for the other parameters. The authors conclude that ascorbic acid promotes 1,25(OH)2D3 synthesis at a paraphysiologic dose (150 mg/die) in humans but this synthesis is inhibited at higher doses (1,000 mg/die). The latter effect by Ca + + or by an effect of ascorbate on 1 alpha-hydroxylase enzyme could be mediated.
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页码：162 / 167
页数：6
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