Vitamin A Supplementation and Retinol Metabolism in the Neonatal Period

出生时，肝脏和血浆中的维生素A(VA、视黄醇)浓度比老年人低得多 儿童和吃得饱的成年人。新生儿的VA营养需要量仅通过以下方式估计 测定母乳中维生素A的消耗量，但新生儿S对维生素A的真实代谢需要 是未知的。在VA补充试验中，出生后不久就会注射大剂量的维生素A 在VA缺乏被认为是公共健康问题的国家进行，以确定发病率 和死亡率降低，但还没有VA代谢的生理模型来帮助指导公共卫生 专家和政策制定者决定新生儿是否能够储存和保留大剂量的VA。 假设是维生素A补充剂与安慰剂，以及维生素A及其活性代谢物的组合 维甲酸(RA)，VARA，与单独的VA相比，将改变新生儿的全身视黄醇动力学。目标 利用数学模型检验VARA是否比VA更有效地引导视黄醇进入 特定组织(肺和其他器官)，以及产妇产后饮食VA是否改变视黄醇 新生儿的新陈代谢。AIMS还测试VA和VARA是否有利于影响炎症 氧气治疗引起的肺部反应，通常是低出生体重儿所必需的。 这些研究将产生关于视黄醇的吸收、储存和利用的新知识，以及 新生儿的分子因素和功能结局。这项研究将对理解 新生儿视黄醇生理学.VA营养要求.向国际和国内公众翻译 卫生政策决定；并有可能转化为改善新生儿重症监护。

At birth, the concentrations of vitamin A (VA, retinol) in liver and plasma are much lower than in older children and well-fed adults. The VA nutritional requirement of the neonate has only been estimated by determining the amount of VA consumed in breast milk, but the neonate¿s true metabolic requirement for VA is not known. VA supplementation trials in which a large bolus dose is delivered soon after birth are being conducted in countries where VA deficiency is considered a public health problem to determine if morbidity and mortality are reduced, yet there is no physiological model of VA metabolism to help guide public health professionals and policy makers in deciding if neonates are able to store and retain a large bolus dose of VA. The hypothesis is that VA supplementation vs. placebo, and a combination of VA and its active metabolite retinoic acid (RA), VARA, compared to VA alone, will alter whole-body retinol kinetics in neonates. The aims make use of mathematical modeling to test whether VARA is more effective than VA in directing retinol into specific tissues (lungs, and other organs), and whether maternal postpartum dietary VA alters retinol metabolism in the neonate. The aims also test whether VA and VARA favorably affects the inflammatory response of the lungs caused by oxygen treatment, as is frequently necessary for low birth weight infants. These studies will generate new knowledge on the absorption, storage and utilization of retinol, together with molecular factors and functional outcomes in neonates. The research will be significant for understanding neonatal retinol physiology; VA nutritional requirements; for translation to international and national public health policy decisions; and potentially for translation to improved neonatal intensive care.