Iron and the Breast-fed Infant

描述(从申请者的描述中扫描)：数量不断增加 婴儿享受母乳喂养的时间越来越长 句号。延长母乳喂养时间是相对未知的领域，因为 从营养的角度来看。铁营养是一个已经存在的领域 担忧。出生时存在的铁库为正常婴儿提供所有的铁 在生命的前5-6个月内需要成长。但在钢铁商店被 筋疲力尽的婴儿依赖于饮食中的铁来源。单靠母乳 只提供婴儿生长所需的铁的一小部分。互补性 食物中有效铁的含量差异很大，似乎不太可能 婴儿总是得到必要数量的铁。推定： 长时间哺乳会导致铁缺乏的风险由一种 先导研究。6个月后，几个婴儿缺铁， 有些人甚至因为缺铁而贫血。药用铁的供应 1~5个半月龄对铁营养状况无明显改善作用。我们的其他研究 单位已经表明，婴儿重新排泄到粪便中的数量可观 吸收了铁。这项建议建立在这些早期研究的基础上。在特定目标中1 我们建议生成一个关于铁营养状况的大致图景 母乳喂养的婴儿(特别是长期母乳喂养的婴儿 期间)和补充的食物，以及铁的量 它们是由此衍生出来的。将对1至24个月的婴儿进行纵向研究。 年纪大了。从公共卫生的角度来看，迫切需要这样做 信息，因为它将描绘出 有问题。同样迫切的是需要找到预防缺铁的方法。 具体目标2的目的是探索两种不同药物的疗效 补充铁质的养生法。一个是提供药用铁(铁 水滴)，另一种是每天喂一罐铁加固的 谷类和水果的组合，都是从4到9个月大的。我们期待着这些 养生方法要有效，有益效果要持续到 补充期。具体目标3涉及以下机制： 允许大多数母乳喂养的婴儿保持良好的铁状态，尽管铁含量较低 母乳中的铁含量。我们也希望解开为什么铁 在我们的初步研究中，补充剂对年轻婴儿无效。我们 将使用两种稳定的(非放射性)铁同位素来确定吸收情况 以及4个月和9个月大的母乳喂养婴儿的铁排泄量和 补充和不补充铁的情况下。我们预计会发现婴儿 当粪便中的铁存储已满时，将铁重新排泄到粪便中，但保留了大部分 当铁储备不足时，吸收的铁的比例。

DESCRIPTION (Scanned from the applicant's description): Increasing numbers of infants are enjoying the benefits of breast feeding for longer and longer periods. Prolonged breast feeding is relatively uncharted territory from a nutritional point of view. Iron nutrition is one area where there has been concern. Iron stores present at birth provide all the iron the normal infant needs for growth during the first 5-6 months of life. But after iron stores are exhausted the infant depends on a dietary source of iron. Breast milk alone provides only a fraction of the iron the infant needs for growth. Complementary foods vary widely in content of available iron, and it appears unlikely that infants always receive the necessary amounts of iron. The presumption that prolonged breast feeding engenders a risk of iron deficiency was born out by a pilot study. After 6 months of age several infants became iron deficient and some even became anemic due to iron deficiency. Provision of medicinal iron from 1 to 5 1/2 months of age did not improve iron status. Other studies in our unit have shown that infants re-excrete into the stool appreciable amounts of absorbed iron. This proposal builds on these earlier studies. In Specific Aim 1 we propose to generate a broad picture of the iron nutritional status of breast-fed infants (specifically, infants who are breast-fed for prolonged periods) and of the complementary foods they are fed and the amount of iron they derive thereof. Infants will be studied longitudinally from 1 to 24 months of age. From a public health point of view there is an urgent need for this information because it will delineate the magnitude and the nature of the problem. Equally urgent is the need to find ways of preventing iron deficiency. The objective of Specific Aim 2 is to explore the efficacy of two different regimens of iron supplementation. One is the provision of medicinal iron (iron drops), the other is the feeding of one jar per day of an iron-fortified cereal-fruit combination, both from 4 to 9 months of age. We expect these regimens to be effective and the beneficial effects to persist beyond the supplementation period. Specific Aim 3 is concerned with the mechanisms that allow most breast-fed infants to remain in good iron status despite the low iron content of breast milk. We also hope to solve the puzzle why iron supplementation was ineffective in the young infants in our pilot study. We will use two stable (non-radioactive) isotopes of iron to determine absorption and excretion of iron by breast-fed infants both at 4 and 9 months of age and with and without iron supplementation. We expect to find that infants re-excrete iron into the feces when their iron stores are full, but retain most of the absorbed iron when iron stores are low.