富含类胡萝卜素蔬菜在改善儿童维生素A营养状况中的作用研究

目的：　选择维生素Ａ（ＶＡ）摄入量较低的儿童，进行为期１０ 周干预，测定总体内ＶＡ贮存是否受富含类胡萝卜素蔬菜摄入量的影响。方法：　健康儿童４１ 名，年龄５．３～６．５ 岁。分为两组，即补充黄绿色蔬菜组（干预组）和常规蔬菜组（对照组）。对照组维持原来膳食方式（当地秋冬季以浅色蔬菜为主），平均浅色蔬菜摄入量为２２４ｇ／ｄ，而干预组为３４ｇ；干预组增加黄绿色蔬菜摄入量，平均摄入黄绿色蔬菜为２３８ｇ／ｄ，对照组为５６ｇ。实验前后，分别给每个儿童口服３ｍ ｇ 生理剂量ＶＡ－ｄ８ 或ＶＡ－ｄ４。在给予标记的ＶＡ后，将每组儿童分成两组，分别于第３ 天或第２１ 天采静脉血，测量实验前后儿童体内ＶＡ总贮存。结果：　对照组实验前视黄醇－ｄ８ 的平均百分丰度与实验后第３ 天和第２１ 天的ＶＡ－ｄ４ 平均百分丰度有显著差异，而干预组，无显著差异。实验前后，给予口服标记量后第２１ 天，对照组循环中标记视黄醇丰度变化大于干预组。干预组平均总体ＶＡ贮存无变化，而对照组有降低趋势，干预组可防止每个儿童视黄醇贮存的丢失２７μｍ ｏｌ。干预组儿童ＶＡ前体类胡萝卜素摄入量（全反式－β－胡萝卜素和其它ＶＡ 前体类胡萝卜素）高于对照组，分别多了１８６ ５９０μｇ

STUDY ON THE ROLE OF VEGETABLES RICH IN CAROTENOIDS IN THE IMPROVEMENT OF VITAMIN A STORES IN CHILDREN

This study was to determine whether vitamin A status could be sustained or improved by increasing the dietary intake of carotenoid rich vegetables. Methods:The intervention was conducted over a ten weeks period in a kindergarten in Tai an City of Shandoing Province. Forty one children from two classes were selected, aged 5.3～6.5 years old, and were divided by class into two groups. One group (control group) was supplemented ～238 g/day child of green yellow vegetables and 34 g/day child of light colored vegetables. Another group (intervention group) consumed the usual diet with only 56 g/day child of green yellow vegetables and 193 g/day child of light colored vegetables. Vitamin A d 8 and vitamin A d 4 were given respectively before and after the interventions and their enrichments in the circulation were determined using gas chromatography/mass spectrometry for investigating vitamin A body stores. Results:The effect of the intervention on the changes of enrichement of labeled retinol in the circulation at 21d after a labeled oral dose before and after the vegetable intervention was greater in the control group than in the intervention group. Mean total body stores of vitamin A did not change in intervention group. However, in the control group, a trend of decrease in total body stores of -27μmole(-7 700μg) of vitamin A (P=0.05) was observed. Thus, the estimated carotenoid intake of children in the intervention group was higher by 186 590μg in all trans β carotene and by 38 540μg in the other provitamin A carotenoids than that of the control group. Based on our data, we can calculate that the provitamin A carotenoids (mainly β carotene) from vegetable origin provided an estimated vitamin A equivalence of 27 to 1 and 14 to 1 by a molar ratio. Conclusion:The dietary green yellow vegetables can provide and maintain the adequate vitamin A nutrition to the kindergarten children.