[中国成年人中年受试者β-胡萝卜素-维生素A等效性评估]

[Evaluation on beta-carotene-vitamin A equivalence of middle-aged subjects in Chinese adults].

作者信息

Wang Zhi-Xu, Gu Yi-Guang, Zhang Chuan-Dong, Su Dong, Wang Yin, Yin Shi'an

机构信息

Qingdao University Medical College, Qingdao 266021, China.

出版信息

Wei Sheng Yan Jiu. 2006 Jan;35(1):59-62.

PMID:16598936

Abstract

OBJECTIVE

As an extended study of beta-Carotene-vitamin A equivalence in Chinese adults, we carried out an experiment on 10 (5 males and 5 females) rural volunteers aged 38 - 49 years, which would be complementary to the early reported study on subjects aged 50 - 60 years.

METHODS

Ten healthy Chinese adult volunteers aged 38-49 years were recruited in a 56 days experiment, which included residency in the Metabolic Research Unit (first 10 days and in home (last 46 days). A physiological dose of 2H8 beta-C (11,011 (nmole or 6 mg) in oil was given with a liquid diet (25% energy from fat) to the volunteers in the first day of the experiment. Three days after the 2H8 beta-C, each volunteer took a reference dose of 2H8 retinyl acetate (8,915 nmole or 3 mg) in oil with the same liquid diet. Serum samples were collected at 0, 3, 5, 7, 9, 11 and 13 hours of the first and the fourth days of study, and fasting serum samples were also collected daily in first 10 days and then weekly at morning of 14th, 21st, 28th, 35th, 42nd, 49th and 56th day after a 12-hours overnight fast. Serum retinol and carotenoids concentrations were measured by high performance liquid chromatography (HPLC). Also retinol fraction was extracted from serum and isolated by HPLC. The serum retinal enrichments were determined by using gas chromatograph/mass spectrometry with electron capture negative chemical ionization (GC-MS).

RESULTS

The average 52-day area under the serum 2H4 retinol response curve (from the 2H8 beta-C dose) was (1289 +/- 547) nmol/d and the 52-day area under the serum 2H8 retinol response curve (from the 2H8 retinyl acetate dose) was (3560 +/- 1058) nmol/d. By using 2H8 retinyl acetate as the vitamin A reference, the 2H4 retinol formed from 2H8 beta-C (11,011 nmol) was calculated to be equivalent to (3434 +/- 1449) nmol of retinol. The calculated conversion factor of beta-C to retinol ranged from 2.00 - 9.61 to 1 with an average of (3.89 +/- 2.76) to 1 on a molar basis, or 3.76 - 18.05 to 1 with an average of (7.30 +/- 5.18) to 1 on a weight basis.

CONCLUSION

The conversion of beta-C to vitamin A in 10 middle-aged Chinese adults had been quantitatively determined by using a stable isotope reference method, and an average conversion ratio of 7.30 : 1 to 1 on a weight basis was found in this study.

摘要

目的

作为对中国成年人中β-胡萝卜素-维生素A等效性的一项扩展研究，我们对10名年龄在38至49岁之间的农村志愿者（5名男性和5名女性）进行了一项实验，这将是对早期报道的关于50至60岁受试者研究的补充。

方法

招募了10名年龄在38 - 49岁之间的健康中国成年志愿者，进行为期56天的实验，其中包括在代谢研究室居住（前10天）和在家中（后46天）。在实验的第一天，给志愿者服用生理剂量的油剂2H8β-C（11,011纳摩尔或6毫克），同时搭配流质饮食（脂肪提供25%的能量）。在服用2H8β-C三天后，每位志愿者服用参考剂量的油剂2H8醋酸视黄酯（8,915纳摩尔或3毫克），饮食相同。在研究的第一天和第四天的0、3、5、7、9、11和13小时采集血清样本，在最初的10天每天还采集空腹血清样本，之后在第14、21、28、35、42、49和56天的早晨，经过12小时空腹后每周采集一次空腹血清样本。通过高效液相色谱法（HPLC）测定血清视黄醇和类胡萝卜素浓度。同时从血清中提取视黄醇组分并通过HPLC分离。使用带有电子捕获负化学电离的气相色谱/质谱联用仪（GC-MS）测定血清视黄醛富集情况。

结果

血清2H4视黄醇反应曲线（来自2H8β-C剂量）的平均52天曲线下面积为（1289±547）纳摩尔/天，血清2H8视黄醇反应曲线（来自2H8醋酸视黄酯剂量）的平均52天曲线下面积为（3560±1058）纳摩尔/天。以2H8醋酸视黄酯作为维生素A参考标准，计算得出由2H8β-C（11,011纳摩尔）形成的2H4视黄醇相当于（3434±1449）纳摩尔视黄醇。计算得出的β-C对视黄醇的转化因子在摩尔基础上为2.00 - 9.61比1，平均为（3.89±2.76）比1；在重量基础上为3.76 - 18.05比1，平均为（7.30±5.18）比1。