Tang G, Gu X, Hu S, Xu Q, Qin J, Dolnikowski G G, Fjeld C R, Gao X, Russell R M, Yin S
Jean Mayer US Department of Agriculture, Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
Am J Clin Nutr. 1999 Dec;70(6):1069-76. doi: 10.1093/ajcn/70.6.1069.
Vitamin A activity of plant provitamin A carotenoids is uncertain.
The objective was to determine whether plant carotenoids can sustain or improve vitamin A nutrition during the fall season in kindergarten children in the Shandong province of China.
The serum vitamin A concentration of 39% of the children was <1.05 micromol/L and of 61% of the children was > or = 1.05 micromol/L. For 5 d/wk for 10 wk, 22 children were provided approximately 238 g green-yellow vegetables/d and 34 g light-colored vegetables/d. Nineteen children maintained their customary dietary intake, which included 56 g green-yellow vegetables/d and 224 g light-colored vegetables/d. Octadeuterated and tetradeuterated vitamin A were given before and after the interventions, respectively, and their enrichments in the plasma were determined by gas chromatography-mass spectrometry. Serum retinol and carotenoid concentrations were measured by HPLC.
Carotenoid nutrition improved after consumption of green-yellow vegetables. Serum concentrations of retinol were sustained in the group fed green-yellow vegetables but decreased in the group fed light-colored vegetables (P < 0.01). The isotope-dilution tests confirmed that total-body vitamin A stores were sustained in the group fed green-yellow vegetables, but decreased 27 micromol (7700 microg retinol) per child, on average, in the group fed light-colored vegetables (P < 0.06).
Green-yellow vegetables can provide adequate vitamin A nutrition in the diet of kindergarten children and protect them from becoming vitamin A deficient during seasons when the provitamin A food source is limited.
植物性维生素A原类胡萝卜素的维生素A活性尚不确定。
确定在中国山东省幼儿园儿童秋季期间，植物类胡萝卜素能否维持或改善维生素A营养状况。
39%的儿童血清维生素A浓度<1.05微摩尔/升，61%的儿童血清维生素A浓度≥1.05微摩尔/升。连续10周，每周5天，为22名儿童每天提供约238克绿黄色蔬菜和34克浅色蔬菜。19名儿童维持其习惯饮食摄入量，其中包括每天56克绿黄色蔬菜和224克浅色蔬菜。分别在干预前后给予十八氘代和十四氘代维生素A，并通过气相色谱-质谱法测定它们在血浆中的富集情况。通过高效液相色谱法测量血清视黄醇和类胡萝卜素浓度。
食用绿黄色蔬菜后，类胡萝卜素营养状况得到改善。食用绿黄色蔬菜组的血清视黄醇浓度得以维持，而食用浅色蔬菜组的血清视黄醇浓度下降（P<0.01）。同位素稀释试验证实，食用绿黄色蔬菜组的体内维生素A储备得以维持，但食用浅色蔬菜组平均每名儿童体内维生素A储备减少27微摩尔（7700微克视黄醇）（P<0.06）。
绿黄色蔬菜可为幼儿园儿童饮食提供充足的维生素A营养，并在维生素A原食物来源有限的季节保护他们不出现维生素A缺乏。
