Lindblad B S, Patel M, Hamadeh M, Helmy N, Ahmad I, Dawodu A, Zaman S
Department of Paediatrics, Aga Khan University, Karachi, Pakistan.
J Trop Pediatr. 1998 Apr;44(2):96-9. doi: 10.1093/tropej/44.2.96.
Cut-off levels for serum retinol levels of 20 micrograms/dl for marginal and 10 micrograms/dl for definite deficiency have been advocated and extensively used in population studies. However, the blood serum levels of retinol of the newborn are known to be very low and although the age dependency of the retinol binding protein has been described, the normal levels of serum retinol at different ages have not been reported from larger series. While studying poor populations of young infants in Lahore, Pakistan, we thought it necessary to try to achieve appropriate reference values by analysing the levels of serum retinol of expatriates from the Indian subcontinent who live in the affluent United Arab Emirates, where retinol deficiency is not seen either at the hospital or the community levels. We have studied material, cord blood, infantile and adult levels of retinol and found a highly significant age relationship of serum retinol levels. During very early infancy the 'normal' mean is below what has been considered deficiency. This is new information and important in the evaluation of retinol status of individuals as well as populations. In addition, we found lower levels in women, pregnant or non-pregnant, than those in adult men. This sex difference in adults was not seen in infants. We recommend a cut off level for deficiency of 10 micrograms/dl, but only for those above 1 month of postnatal age.
血清视黄醇水平的临界值，即边缘性缺乏为20微克/分升，明确缺乏为10微克/分升，这一标准已被提倡并广泛应用于人群研究。然而，众所周知新生儿的血清视黄醇水平非常低，虽然已经描述了视黄醇结合蛋白的年龄依赖性，但尚未有来自大量样本的不同年龄血清视黄醇正常水平的报道。在对巴基斯坦拉合尔的贫困婴幼儿群体进行研究时，我们认为有必要通过分析居住在富裕的阿拉伯联合酋长国的印度次大陆侨民的血清视黄醇水平来尝试获得合适的参考值，在那里无论是医院还是社区层面都未发现视黄醇缺乏情况。我们研究了视黄醇的物质、脐血、婴儿和成人水平，发现血清视黄醇水平与年龄有高度显著的关系。在婴儿早期，“正常”平均值低于被认为是缺乏的水平。这是新的信息，对评估个体以及人群的视黄醇状态很重要。此外，我们发现无论怀孕与否，女性的视黄醇水平都低于成年男性。这种成年人中的性别差异在婴儿中未观察到。我们建议将缺乏的临界值设定为10微克/分升，但仅适用于出生后1个月以上的人群。
