Olson J A, Gunning D B, Tilton R A
Am J Clin Nutr. 1984 Jun;39(6):903-10. doi: 10.1093/ajcn/39.6.903.
To assess the age-dependent vitamin A status of children, liver samples taken at autopsy from 170 American children 0-15 yr of age were analyzed for vitamin A and carotenoids. The median liver vitamin A concentration at birth was low (11 micrograms retinol/g), remained constant to 3 mo, rapidly increased to 4 yr (130 micrograms/g) and then remained constant into adolescence. In contrast the vitamin A status of premature infants deteriorated after birth. Of infants less than 3 mo, approximately one-fourth and two-thirds showed liver vitamin A concentrations less than or equal to 5 micrograms retinol/g and less than or equal to 20 micrograms/g, respectively. On the other hand, essentially all infants greater than or equal to 6 months showed an adequate vitamin A status, defined as liver stores greater than 20 micrograms retinol/g liver. Liver carotenoid concentrations did not meaningfully correlate with age or with vitamin A concentrations. Parameters that did not significantly affect the vitamin A concentration were: 1) height and weight in infants less than 1 mo, except in the highest weight-height groups, 2) sex, although values of females were slightly higher than males, and 3) causes of death.
为评估儿童年龄依赖性维生素A状况,对170名0至15岁美国儿童尸检时采集的肝脏样本进行了维生素A和类胡萝卜素分析。出生时肝脏维生素A浓度中位数较低(11微克视黄醇/克),至3个月时保持稳定,4岁时迅速升至130微克/克,然后在青春期保持稳定。相比之下,早产儿出生后维生素A状况恶化。在3个月以下的婴儿中,分别约有四分之一和三分之二的婴儿肝脏维生素A浓度低于或等于5微克视黄醇/克和低于或等于20微克视黄醇/克。另一方面,基本上所有6个月及以上婴儿的维生素A状况充足,定义为肝脏储存量大于20微克视黄醇/克肝脏。肝脏类胡萝卜素浓度与年龄或维生素A浓度无显著相关性。对维生素A浓度无显著影响的参数有:1)1个月以下婴儿的身高和体重,但最高体重-身高组除外;2)性别,尽管女性的值略高于男性;3)死因。