Dell Medical School at the University of Texas at Austin, Austin, TX.
RTI International, Durham, NC.
J Pediatr. 2021 Apr;231:36-42.e2. doi: 10.1016/j.jpeds.2020.10.071. Epub 2020 Nov 2.
To calculate the amount of bioavailable iron consumed among 6- to 12- month-old infants considering differences in iron bioavailability among dietary iron sources and to compare this with current recommended intakes.
We used the Feeding Infants and Toddlers Study database of dietary intakes from 2016 and the estimated bioavailability of dietary iron sources to evaluate the proportion of infants whose calculated total daily absorbed iron fell below physiologic requirements, that is, the recommended amount needed to fully support growth and erythropoiesis.
The calculated daily iron absorption was below the recommended amount in 54.3% of infants evaluated ranging from 19.5% of 448 exclusively formula-fed infants, to 95.8% of 296 exclusively breastfed infants and 72.2% of 102 mixed fed infants. The calculated mean iron absorption of 6- to 9- month-old breastfed infants was 0.27 mg/day, far less than the estimated physiologic requirement of 0.69 mg/day. The most highly bioavailable iron, heme iron, was <12% of the contributor to total iron absorbed in breastfed infants.
These data indicate a need for further education and public health policies to support increased iron intake in 6- to 12- month-old infants, emphasizing those receiving any breast milk. Exclusively formula-fed infants are at lower risk, but rates of low absorbed iron indicate that all infants may need monitoring for clinical evidence of low iron status. Consideration should be given to increasing the proportion of heme iron obtained from animal products in the diet where feasible.
考虑不同膳食铁源的铁生物利用度差异,计算 6-12 个月龄婴儿可利用铁的摄入量,并与当前推荐摄入量进行比较。
我们使用 2016 年膳食摄入量的喂养婴儿和幼儿研究数据库以及膳食铁源的估计生物利用度,评估计算得出的每日总吸收铁量低于生理需求(即完全支持生长和红细胞生成所需的推荐量)的婴儿比例。
在所评估的婴儿中,有 54.3%的婴儿计算出的每日铁吸收量低于推荐量,范围从 448 名完全配方奶喂养的婴儿中 19.5%,到 296 名纯母乳喂养的婴儿中 95.8%和 102 名混合喂养的婴儿中 72.2%。6-9 月龄母乳喂养婴儿计算出的平均铁吸收率为 0.27mg/天,远低于估计的 0.69mg/天的生理需求。最具生物利用度的铁(血红素铁)在母乳喂养婴儿总铁吸收量中的贡献率<12%。
这些数据表明,需要进一步教育和公共卫生政策来支持 6-12 个月龄婴儿增加铁摄入量,尤其强调那些接受母乳喂养的婴儿。完全配方奶喂养的婴儿风险较低,但低吸收铁的比例表明,所有婴儿可能都需要监测是否存在缺铁的临床证据。应考虑在可行的情况下增加饮食中动物产品来源的血红素铁比例。