Kattelmann K K, Ho M, Specker B L
Nutrition, Food Science, and Hospitality Department, South Dakota State University, Box 2275A, Brookings, SD 57007 605/688-4045, USA.
J Am Diet Assoc. 2001 Apr;101(4):443-7. doi: 10.1016/S0002-8223(01)00114-6.
The timing of introduction of complementary food to an infant's diet is variable throughout the world. Our objective was to determine whether early introduction of complementary foods affects iron and zinc status of formulated infants at 12, 24, and 36 months of age.
A randomized, prospective trial was conducted. Infants were randomly assigned to receive either a) early introduction (at 3 to 4 months of age) of commercially prepared or parent's choice of complementary foods; or b) late introduction (at 6 months of age) of commercially prepared complementary foods or parent's choice of complementary foods. In addition to complementary foods, infants were fed commercial infant formula as recommended by their pediatrician. Hemoglobin, mean corpuscular volume, and serum ferritin and zinc concentrations were determined at 12, 24, and 36 months of age. Three-day diet diaries were completed at 3, 6, 12, 18, 24, 30, and 36 months of age.
SUBJECTS/SETTING: One hundred seventy-five infants younger than 3 months were recruited by mailings to parents in the Cincinnati area. Of these, 172 were enrolled, 90 in the early-introduction group and 82 in the late-introduction group. One hundred thirty-three infants (n = 67 in the early, n = 66 in the late group) completed the study.
Student t test and regression analyses were used to determine whether there were group differences and whether there was a relationship between serum parameters and dietary intake.
Infants fed complementary foods early had significantly greater iron intakes until 6 months of age; however, there were no differences in the iron status parameters (ferritin, hemoglobin, and mean corpuscular volume) at 12, 24, or 36 months of age. The early introduction group consumed slightly less zinc than the late introduction group at 5 months (4.4 vs 4.8 mg/day, P < .01) and 6 months (4.4 vs 4.7 mg/day, P < .01). At all other times there were no differences between the early and late group in zinc intakes. The serum zinc concentration was not associated with dietary zinc. Both groups had normal serum zinc concentrations at 12, 24, and 36 months and there were no differences between groups.
APPLICATIONS/CONCLUSIONS: The iron and zinc status of infants in this study was not influenced by the timing or type of complementary foods introduced. However, the infants were formula fed and the mean iron and zinc intakes that were equal or greater than the Recommended Dietary Allowances for the first 6 months of age.
在全球范围内，给婴儿饮食中引入辅食的时间各不相同。我们的目的是确定过早引入辅食是否会影响配方奶喂养婴儿在12、24和36月龄时的铁和锌状况。
进行了一项随机前瞻性试验。婴儿被随机分配接受以下两种方式之一：a）过早引入（3至4月龄）市售或家长选择的辅食；或b）过晚引入（6月龄）市售辅食或家长选择的辅食。除辅食外，婴儿按照儿科医生的建议喂养市售婴儿配方奶粉。在12、24和36月龄时测定血红蛋白、平均红细胞体积、血清铁蛋白和锌浓度。在3、6、12、18、24、30和36月龄时完成3天饮食日记。
研究对象/地点：通过向辛辛那提地区的家长邮寄招募了175名3个月以下的婴儿。其中，172名婴儿入组，90名进入过早引入组，82名进入过晚引入组。133名婴儿（过早引入组67名，过晚引入组66名）完成了研究。
采用学生t检验和回归分析来确定组间是否存在差异以及血清参数与饮食摄入量之间是否存在关系。
过早喂养辅食的婴儿在6月龄前铁摄入量显著更高；然而，在12、24或36月龄时，铁状况参数（铁蛋白、血红蛋白和平均红细胞体积）没有差异。过早引入组在5个月（4.4对4.8毫克/天，P <.01）和6个月（4.4对4.7毫克/天，P <.01）时锌摄入量略低于过晚引入组。在所有其他时间，过早和过晚引入组的锌摄入量没有差异。血清锌浓度与饮食锌无关。两组在12、24和36月龄时血清锌浓度均正常，组间无差异。
应用/结论：本研究中婴儿的铁和锌状况不受引入辅食的时间或类型的影响。然而，这些婴儿是配方奶喂养，且前6个月的平均铁和锌摄入量等于或高于推荐膳食摄入量。
