DIETARY MINERAL BIOAVAILABILITY IN PREMATURE INFANTS

早产儿膳食矿物质的生物利用度

• 批准号: 3314513
• 负责人: RICHARD A. EHRENKRANZ
• 金额: $ 16.84万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-01-01 至 1987-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3314513
• 关键词: baby food; clinical chemistry; copper; developmental nutrition; dietary calcium; dietary supplements; dietary trace element; gastrointestinal nutrient absorption; gestational age; growth /development; human birth weight; human milk; human subject; nutrition related tag; premature infant human; stable isotope; zinc

The intrauterine growth rate has become the standard to which postnatal growth of premature infants is compared, and the body composition of the full-term infant has become the standard from which nutrient requirements have been calculated. Metabolic balance studies, performed with premature infants to determine whether the amount of the dietary nutrient retained by the body per unit time matched the in utero accumulation of that nutrient over an equivalent period of time, have often demonstrated negative nutrient balances and have suggested body deficits of the nutrient under study. This has been particularly the experience with minerals such as calcium, zinc, and copper. Furthermore, due to technical difficulties that can either underestimate or overestimate both absorption and retention, metabolic balance studies produce variable results. Therefore in this investigation we propose to directly measure the bioavailability of dietary calcium, zinc, and copper in premature infants with stable isotope enrichment technology. Sixty appropriate for gestational age infants with birthweights less than or equal to 1,500 gm that tolerate full enteral nutrition of at least 100 kcal/kg/day by 7 days of age will form the final study population. These infants will be divided into 3 feeding groups of 20. Group I will receive a proprietary formula that has been specifically designed for the growing premature infant, Group II will receive their own mother's milk (PTHM), and Group III will receive fortified-PTHM (a mixture of their own mother's PTHM with a powdered mineral supplement). Ten infants in each group will have a birthweight less than 1,250 gm (Subgroup A) and 10 will have a birthweight between 1,250 and 1,500 gm (Subgroup B). Calcium, zinc, and copper bioavailability will be assessed by the addition of a solution containing tracer amounts of stable, non-radioactive, naturally occurring isotopes of those minerals, 46Ca, 70Zn, and 65Cu, to one feeding, followed by a 72 hour collection of stool and urine. Isotopic and mineral analyses of the stool and urine samples will then permit an accurate calculation of the fractional absorption of each administered stable isotope. Two bioavailability studies will be performed with each infant; the first between 10 and 14 days of age and the second at a body weight of about 1,500 gm for the infants in Subgroup A and about 1,750 gm for the infants in Subgroup B. Thus, this study will determine the effect of post-natal age on dietary calcium, zinc, and copper bioavailability, while comparing their bioavailability from PTHM, formula, and fortified-PTHM.

宫内生长速度已成为产后的标准 比较早产儿的生长情况，以及早产儿的身体成分 足月婴儿营养需求已成为标准 已被计算。 过早进行的代谢平衡研究 以确定婴儿是否保留了膳食营养素的量 身体每单位时间与子宫内该营养素的积累相匹配 在相当一段时间内，经常表现出负面的 营养平衡，并建议身体缺乏营养 学习。 这尤其是矿物的经验，例如 钙、锌和铜。 此外，由于技术困难 可能低估或高估吸收和保留， 代谢平衡研究产生不同的结果。 因此在这个 我们建议直接测量膳食的生物利用度 早产儿的钙、锌和铜具有稳定同位素 浓缩技术。 六十岁适合胎龄婴儿 出生体重小于或等于 1,500 克，可耐受全肠内喂养 7日龄时至少100 kcal/kg/天的营养将形成最终的营养 研究人群。 这些婴儿将被分为 3 个喂养组 20. 第一组将获得经过专门研究的专有配方 专为成长中的早产儿设计，第二组将获得自己的 母乳 (PTHM)，第三组将接受强化 PTHM（混合物 他们自己母亲的 PTHM 与粉末状矿物质补充剂）。 十 每组婴儿的出生体重均小于 1,250 克（亚组 A) 和 10 的出生体重在 1,250 至 1,500 克之间（B 组）。 钙、锌和铜的生物利用度将通过添加来评估 含有示踪量的稳定、非放射性、 这些矿物的天然同位素 46Ca、70Zn 和 65Cu 一次喂食，然后收集 72 小时的粪便和尿液。 同位素 对粪便和尿液样本进行矿物质分析将允许 准确计算每次给药的吸收分数 稳定同位素。 每个药物将进行两项生物利用度研究 婴儿;第一次在 10 到 14 天龄之间，第二次在身体上 A组婴儿体重约1,500克，A组婴儿体重约1,750克 对于 B 亚组的婴儿。因此，本研究将确定效果 产后年龄对膳食钙、锌和铜生物利用度的影响， 同时比较 PTHM、配方奶粉和 强化-PTHM。