Department of Pediatrics, UC Davis Children's Hospital, University of California, Davis, USA.
Early Hum Dev. 2013 Oct;89 Suppl 2:S29-34. doi: 10.1016/j.earlhumdev.2013.08.001. Epub 2013 Aug 30.
Zinc and copper are essential for preterm infants, but recommended requirements from different groups vary widely. Recommended zinc intakes have steadily increased over the years. Although this would be expected to impair copper absorption, recommended copper intakes have not risen in parallel.
To systematically review the literature on zinc and copper retention in preterm infants; to examine the effect on zinc intake on copper retention; and to estimate the zinc and copper intakes required to meet the levels of zinc and copper retention required for normal growth.
Studies reporting zinc and/or copper retention in preterm infants (<36 weeks of gestation) during the first 120 days of life were identified using PubMed. Only studies reporting net retention were included.
Fourteen studies on zinc retention reporting data on 45 different groups were identified. Eleven studies (32 groups) were identified reporting copper retention. Zinc retention was significantly higher at higher zinc intakes, and higher in formula-based diets than in human milk based diets. Zinc intakes of between 1.8-2.4 mg/kg/d (from formula based diets) and 2.3-2.4 mg/kg/d (from human-milk based diets) were required to achieve adequate zinc retention. Copper retention was significantly positively correlated with copper intake and significantly negatively correlated with zinc intake. At the zinc intakes suggested previously (1.8-2.4, 2.3-2.4 mg/kg/d), copper intakes of between 200 and 250 mcg/kg/d are required to ensure adequate copper retention.
Our results support the higher zinc intakes recommended in recent guidelines. However, they suggest that recommended copper intakes have not kept pace with increasing zinc intakes, and that preterm infants may need higher copper intakes than currently recommended.
锌和铜是早产儿所必需的，但不同群体的推荐需求量差异很大。锌的推荐摄入量多年来一直在稳步增加。尽管这预计会损害铜的吸收，但铜的推荐摄入量并没有相应增加。
系统综述早产儿锌和铜保留的文献；检查锌摄入量对铜保留的影响；并估计满足正常生长所需的锌和铜保留水平所需的锌和铜摄入量。
使用 PubMed 确定了在生命的前 120 天内报告早产儿（<36 周）锌和/或铜保留的研究。仅包括报告净保留的研究。
确定了 14 项关于锌保留的研究，报告了 45 个不同组的数据。确定了 11 项（32 组）报告铜保留的研究。锌摄入量越高，锌保留越高，基于配方的饮食比基于人乳的饮食高。需要摄入 1.8-2.4 mg/kg/d（基于配方的饮食）和 2.3-2.4 mg/kg/d（基于人乳的饮食）之间的锌摄入量，以实现足够的锌保留。铜保留与铜摄入量呈显著正相关，与锌摄入量呈显著负相关。在之前建议的锌摄入量（1.8-2.4、2.3-2.4 mg/kg/d）下，需要摄入 200-250 mcg/kg/d 的铜摄入量以确保足够的铜保留。
我们的结果支持最近指南中推荐的更高锌摄入量。然而，它们表明推荐的铜摄入量并没有跟上锌摄入量的增加，早产儿可能需要比目前推荐的更高的铜摄入量。
