Lopez-Teros Veronica, Ford Jennifer Lynn, Green Michael H, Tang Guangwen, Grusak Michael A, Quihui-Cota Luis, Muzhingi Tawanda, Paz-Cassini Mariela, Astiazaran-Garcia Humberto
Nutritional Sciences, Department of Chemical and Biological Sciences, University of Sonora, Hermosillo, Sonora, Mexico.
Department of Nutritional Sciences, Pennsylvania State University, University Park, PA.
J Nutr. 2017 Dec;147(12):2356-2363. doi: 10.3945/jn.117.256974. Epub 2017 Sep 20.
Worldwide, an estimated 250 million children <5 y old are vitamin A (VA) deficient. In Mexico, despite ongoing efforts to reduce VA deficiency, it remains an important public health problem; thus, food-based interventions that increase the availability and consumption of provitamin A-rich foods should be considered. The objectives were to assess the VA equivalence of H-labeled (MO) leaves and to estimate both total body stores (TBS) of VA and plasma retinol kinetics in young Mexican children. β-Carotene was intrinsically labeled by growing MO plants in a HO nutrient solution. Fifteen well-nourished children (17-35 mo old) consumed puréed MO leaves (1 mg β-carotene) and a reference dose of [C]retinyl acetate (1 mg) in oil. Blood (2 samples/child) was collected 10 times (2 or 3 children each time) over 35 d. The bioefficacy of MO leaves was calculated from areas under the composite "super-child" plasma isotope response curves, and MO VA equivalence was estimated through the use of these values; a compartmental model was developed to predict VA TBS and retinol kinetics through the use of composite plasma [C]retinol data. TBS were also estimated with isotope dilution. The relative bioefficacy of β-carotene retinol activity equivalents from MO was 28%; VA equivalence was 3.3:1 by weight (0.56 μmol retinol:1 μmol β-carotene). Kinetics of plasma retinol indicate more rapid plasma appearance and turnover and more extensive recycling in these children than are observed in adults. Model-predicted mean TBS (823 μmol) was similar to values predicted using a retinol isotope dilution equation applied to data from 3 to 6 d after dosing (mean ± SD: 832 ± 176 μmol; = 7). The super-child approach can be used to estimate population carotenoid bioefficacy and VA equivalence, VA status, and parameters of retinol metabolism from a composite data set. Our results provide initial estimates of retinol kinetics in well-nourished young children with adequate VA stores and demonstrate that MO leaves may be an important source of VA.
全球范围内，估计有2.5亿5岁以下儿童缺乏维生素A（VA）。在墨西哥，尽管一直在努力减少VA缺乏，但它仍然是一个重要的公共卫生问题；因此，应考虑采取基于食物的干预措施，以增加富含维生素A原的食物的供应和消费。目的是评估H标记的（MO）叶的VA等效性，并估计墨西哥幼儿的VA总体储存量（TBS）和血浆视黄醇动力学。通过在HO营养液中种植MO植物，β-胡萝卜素被内在标记。15名营养良好的儿童（17 - 35个月大）食用了MO叶泥（1毫克β-胡萝卜素）和参考剂量的[C]醋酸视黄酯（1毫克）油剂。在35天内分10次（每次2或3名儿童）采集血液（每个儿童2份样本）。根据复合“超级儿童”血浆同位素反应曲线下的面积计算MO叶的生物功效，并通过使用这些值估计MO的VA等效性；开发了一个房室模型，通过使用复合血浆[C]视黄醇数据来预测VA TBS和视黄醇动力学。还通过同位素稀释估计TBS。来自MO的β-胡萝卜素视黄醇活性当量的相对生物功效为28%；按重量计算，VA等效性为3.3:1（0.56微摩尔视黄醇:1微摩尔β-胡萝卜素）。血浆视黄醇动力学表明，与成年人相比，这些儿童的血浆视黄醇出现和周转更快，循环更广泛。模型预测的平均TBS（823微摩尔）与使用视黄醇同位素稀释方程应用于给药后3至6天的数据预测的值相似（平均值±标准差：832±176微摩尔；n = 7）。超级儿童方法可用于从复合数据集中估计人群类胡萝卜素生物功效和VA等效性、VA状态以及视黄醇代谢参数。我们的结果提供了VA储存充足的营养良好幼儿视黄醇动力学的初步估计，并表明MO叶可能是VA的重要来源。
