Li Lei, Wang Yin, Wu Jieshu, Zhu Ranfeng
National Institute for Nutrition and Food Safety, Chinese Centre for Disease Control and Prevention, Beijing 100050, China.
Wei Sheng Yan Jiu. 2007 Sep;36(5):547-51.
To determine the bioefficacy of pure beta-carotene and beta-carotene from spinach to vitamin A in schoolchildren of different vitamin A status.
Thirty two schoolchildren aged 7-9 years old were selected and then divided into two groups randomly. Each group included 16 subjects, of which the vitamin A level of 8 subjects was normal, the other 8 subjects suffered from vitamin A deficiency. In the first 7 days, one group was given 5 gram spinach (containing 230 microg 2H10-beta-carotene) before lunch and dinner and the other group was given pure beta-carotene capsule (containing 200 microg beta-carotene). Before breakfast, both groups were given 100 microg 13C10 retinal acetate capsule. Blood was drawn on the 3, 7, 8, 22 and 28 day. HPLC and GC-MS were used to determine the retinol concentration and enrichment of isotope and then calculate the bioefficacy of pure beta-carotene and beta-carotene from spinach to vitamin A.
The conversion factors of pure beta-carotene to vitamin A in oil capsule were: 2.9:1 for the children with normal vitamin A status, 3.2:1 for those suffering from marginal vitamin A deficiency. The conversion factors of spinach beta-carotene to vitamin A were 10.1:1 and 10.3:1 for the children with normal and low vitamin A status, respectively.
The vitamin A conversion bioefficacy of pure beta-carotene from oil capsule is much higher than that of spinach. There is no difference of beta-carotene bioefficacy to vitamin A for children with different vitamin A status.
确定纯β-胡萝卜素和菠菜中的β-胡萝卜素对不同维生素A状态学龄儿童维生素A的生物有效性。
选取32名7至9岁的学龄儿童，随机分为两组。每组16名受试者，其中8名受试者维生素A水平正常，另外8名受试者患有维生素A缺乏症。在开始的7天里，一组在午餐和晚餐前服用5克菠菜（含230微克2H10-β-胡萝卜素），另一组服用纯β-胡萝卜素胶囊（含200微克β-胡萝卜素）。早餐前，两组均服用100微克13C10视黄醇醋酸酯胶囊。在第3、7、8、22和28天采集血液。采用高效液相色谱法（HPLC）和气相色谱-质谱联用仪（GC-MS）测定视黄醇浓度和同位素富集情况，然后计算纯β-胡萝卜素和菠菜中的β-胡萝卜素对维生素A的生物有效性。
油胶囊中纯β-胡萝卜素转化为维生素A的转化系数为：维生素A水平正常的儿童为2.9:1，边缘性维生素A缺乏的儿童为3.2:1。菠菜β-胡萝卜素转化为维生素A的转化系数，维生素A水平正常的儿童为10.1:1，维生素A水平低的儿童为10.3:1。
油胶囊中纯β-胡萝卜素转化为维生素A的生物有效性远高于菠菜。不同维生素A状态的儿童，β-胡萝卜素转化为维生素A的生物有效性无差异。
