Ribaya-Mercado J D, Mazariegos M, Tang G, Romero-Abal M E, Mena I, Solomons N W, Russell R M
Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Am J Clin Nutr. 1999 Feb;69(2):278-84. doi: 10.1093/ajcn/69.2.278.
Deuterated retinol dilution (DRD) gives quantitative estimates of total body stores of vitamin A.
In elderly people, we studied 1) the time when an oral dose of deuterated vitamin A equilibrates with body stores, 2) whether serum ratios of deuterated to nondeuterated retinol (D:H) at 3 or 6 d postdosing predicted body stores, and 3) the ability of DRD to detect changes in the size of the body vitamin A pool.
A 10-mg oral dose of [2H4]retinyl acetate was administered to 60-81-y-old Guatemalans (n = 47); percentage enrichment of serum retinol with deuterated retinol was determined at 1-3 time points per subject at 3, 6, 7, 14, 20, 21, and 54 d. In subjects from whom blood was obtained at 3 and 21 d (n = 15) and at 6 and 20 d (n = 9), total body stores were calculated by using the formula of Furr et al (Am J Clin Nutr 1989;49:713-6) with 21- or 20-d data and correlated with serum D:H at 3 or 6 d postdosing. Nine subjects received diets containing 982+/-20 microg RE (x+/-SEM) plus 800 microg RE as retinyl acetate supplements for 32 d. DRD, serum retinol, and relative dose response were used to assess vitamin A status before and after the intervention.
Deuterated retinol equilibrated with the body pool by 20 d postdosing. Vitamin A supplementation for 32 d increased body stores, although unexplained exaggerated increases were seen in some subjects. An inverse linear relation was found between estimates of body stores and serum D:H at 3 d postdosing (r = -0.75, P = 0.002); at 6 d postdosing, the correlation was weaker.
DRD can detect changes in total body stores of vitamin A, although factors affecting serum D:H need to be elucidated. Serum D:H 3 d postdosing might be used as an early indicator of total body stores of vitamin A, although a predictive equation will need to be developed.
氘代视黄醇稀释法（DRD）可定量评估体内维生素A储备。
在老年人中，我们研究了1）口服一剂氘代维生素A与体内储备达到平衡的时间，2）给药后3天或6天血清中氘代视黄醇与非氘代视黄醇的比率（D:H）是否能预测体内储备，以及3）DRD检测体内维生素A池大小变化的能力。
向60 - 81岁的危地马拉人（n = 47）口服10 mg [2H4]醋酸视黄酯；在给药后3、6、7、14、20、21和54天，每位受试者在1 - 3个时间点测定血清视黄醇中氘代视黄醇的富集百分比。在给药后3天和21天（n = 15）以及6天和20天（n = 9）采集血液的受试者中，使用Furr等人（《美国临床营养学杂志》1989年；49:713 - 6）的公式，根据21天或20天的数据计算体内储备，并与给药后3天或6天的血清D:H进行相关性分析。9名受试者接受了含有982±20 μg视黄醇当量（x±SEM）加8 μg视黄醇当量醋酸视黄酯补充剂的饮食持续32天。使用DRD、血清视黄醇和相对剂量反应评估干预前后的维生素A状态。
给药后20天，氘代视黄醇与体内储备达到平衡。补充维生素A 32天增加了体内储备，尽管在一些受试者中出现了无法解释的过度增加。给药后3天，体内储备估计值与血清D:H之间呈负线性关系（r = -0.75，P = 0.002）；给药后6天，相关性较弱。
DRD能够检测体内维生素A储备的变化，尽管影响血清D:H的因素有待阐明。给药后3天的血清D:H可能用作体内维生素A储备的早期指标，不过还需要建立一个预测方程。
