Objective: To evaluate the nutritional status of vitamin A (VitA) in breast milk and its influencing factors among lactating women in the Weihai, Yueyang, and Baotou of China.
Methods: From May to July 2014, 403 lactating mothers at (42±7) d postpartum were recruited from three Chinese cities, Weihai in Shandong Province, Yueyang in Hunan Province, and Baotou in Inner Mongolia. Basic information of lactating women and newborns and fish intake information of the lactating women in the last month were collected. The concentration of retinol in breast milk was collected and measured using high-performance liquid chromatography to determine the levels of VitA. According to the breast milk retinol concentration, the nutritional status of breast milk VitA among the lactating women was divi-ded into deficiency (< 1.05 μmol/L) and sufficient (≥1.05 μmol/L). The multivariate quantile regression was used to calculate the adjusted breast milk retinol concentrations. The Kruskal-Wallis H test and the Mann-Whitney U test were used to test the difference of breast milk retinol concentration according to the characteristics of the lactating women. The Logistic regression was used to analyze the effect of characteristics of lactating women on breast milk VitA deficiency.
Results: The M (P25, P75) of breast milk retinol concentration among the Chinese lactating women was 1.15 (0.83, 1.49) μmol/L. Multivariate analysis showed that the adjusted breast milk retinol concentration was related to the regions, maternal age, ethnicity, education levels, body mass index (BMI), parity, gestational age, delivery modes, breastfeeding practice, fish intake and birth weight of the infants. The prevalence of VitA deficiency in breast milk among all the lactating women was 41.9%. In Weihai, Yueyang, and Baotou, the prevalence rates were 34.8%, 39.6%, and 51.5%, respectively. Compared with the women in Weihai, the adjusted OR for breast milk VitA deficiency among the women in Baotou was 1.75 (95%CI: 1.05-2.92). Compared with the women having college and above education, the adjusted OR for breast milk VitA deficiency among those having junior high school and below education were 2.16 (95%CI: 1.10-4.24). Compared with women with low fish intake, the adjusted OR for breast milk VitA deficiency among those with high fish intake were 0.55 (95%CI: 0.36-0.84).
Conclusion: The prevalence of breast milk VitA deficiency among the Chinese lactating women was 41.9%, suggesting that breast milk VitA deficiency in lactating women and inadequate VitA intake for infants were common in China. The women in Baotou, low educational status and low fish intake increased the risk of breast milk VitA deficiency, suggesting that attention should be paid to the nutritional status of lactating women in underdeveloped regions such as inland region, and education for health should be enhanced and food containing VitA such as fish intake should be increased.
目的: 分析中国威海、岳阳、包头三地乳母乳汁维生素A(vitamin A, VitA)水平，评价乳母乳汁VitA的营养状况及其影响因素。
方法: 2014年5月至7月在山东省威海市、湖南省岳阳市和内蒙古包头市于产后(42±7) d募集乳母403例，通过调查问卷收集乳母和新生儿基本信息及乳母近1个月内鱼类摄入情况，采集乳母乳汁并采用高效液相色谱法检测乳汁视黄醇浓度，以此代表VitA水平。依据视黄醇浓度，将乳母乳汁VitA营养状况分为缺乏(< 1.05 μmol/L)和充足(≥1.05 μmol/L)。采用多因素分位数回归计算调整后的乳汁视黄醇浓度，Kruskal-Wallis H检验和Mann-Whitney U检验评估不同特征人群视黄醇浓度差异情况，Logistic回归模型分析乳汁VitA缺乏的可能影响因素。
结果: 中国三地乳母乳汁视黄醇M(P25, P75)为1.15 (0.83, 1.49) μmol/L。多因素分析结果显示，调整后的乳汁视黄醇浓度与乳母居住地区、年龄、民族、受教育程度、体重指数、产次、分娩孕周、分娩方式、哺乳方式、鱼类摄入量和新生儿出生体质量有关。乳母乳汁整体VitA缺乏率为41.9%，威海、岳阳和包头地区的缺乏率分别为34.8%、39.6%和51.5%。与威海地区乳母相比，包头地区乳母乳汁VitA缺乏的调整OR值为1.75 (95%CI: 1.05~2.92)；与受教育程度为大专及以上乳母相比，初中及以下乳母乳汁VitA缺乏的调整OR值为2.16 (95%CI: 1.10~4.24)；与鱼类摄入量少的乳母相比，鱼类摄入量多的乳母乳汁VitA缺乏的调整OR值为0.55 (95%CI: 0.36~0.84)。
结论: 调查地区乳母乳汁整体VitA缺乏率为41.9%，提示乳汁VitA缺乏及婴儿VitA摄入不足情况较为普遍。包头地区、受教育程度低和鱼类摄入量少增加乳汁VitA缺乏发生风险，提示宜重点关注欠发达地区乳母的乳汁营养状况，加强健康教育，增加鱼类等含VitA的食物摄入。[关键词] 维生素A；乳母；乳汁
Keywords: Breast milk; Lactating women; Vitamin A.