Faculty of Food Technology, Latvia University of Life Sciences and Technologies, Rīgas iela 22, LV-3004 Jelgava, Latvia.
Institute of Food Safety, Animal Health and Environment BIOR, Lejupes iela 3, LV-1076 Riga, Latvia.
Nutrients. 2018 Oct 5;10(10):1438. doi: 10.3390/nu10101438.
Zinc is an indispensable element, being involved in many biological processes. Correspondingly, insufficient zinc intake in early youth can detrimentally affect the function of a growing body. The aim of this study was to determine zinc content in breast milk among lactating women in Latvia and factors (maternal diet; mother's and baby's characteristics; breastfeeding pattern) affecting it.
In total, 62 mature milk (at least one month postpartum) samples were collected and pooled within 24 h. Zinc content (mg 100 mL) was determined using inductively coupled plasma mass spectrometry (ICP-MS; Agilent 7700×, Agilent Technologies, Tokyo, Japan).
Zinc content in mature breast milk ranged from 0.01 to 0.34 mg 100 mL with a median (interquartile range) content of 0.10 (0.05⁻0.15) mg 100 mL. Time postpartum was a significant negative predictor for zinc content in breast milk ( = -0.500; = 0.000). Median maternal zinc intake was 10.70 (7.24⁻15.27) mg. Yet, zinc content in breast milk was unaffected by maternal dietary zinc intake ( = 0.155; = 0.221).
Maternal dietary zinc intake was nearly the recommended intake for lactating women (11 mg), but due to low zinc content in breast milk, babies in Latvia might not receive sufficient zinc intake. Future research should aim for the assessment of zinc status by evaluating plasma or serum levels of both mothers and babies.
锌是一种必需元素，参与许多生物过程。相应地，青少年早期摄入不足的锌会对生长中身体的功能产生不利影响。本研究旨在确定拉脱维亚哺乳期妇女母乳中的锌含量以及影响其含量的因素（母亲的饮食；母亲和婴儿的特征；母乳喂养模式）。
共收集并在 24 小时内混合了 62 份成熟乳（产后至少一个月）样本。使用电感耦合等离子体质谱法（ICP-MS；Agilent 7700×，安捷伦科技，东京，日本）测定锌含量（mg/100mL）。
成熟母乳中的锌含量范围为 0.01 至 0.34mg/100mL，中位数（四分位距）为 0.10（0.05⁻0.15）mg/100mL。产后时间是母乳中锌含量的显著负预测因子（=-0.500；=0.000）。母亲锌摄入量中位数为 10.70（7.24⁻15.27）mg。然而，母乳中锌含量不受母亲膳食锌摄入量的影响（=0.155；=0.221）。
母亲的膳食锌摄入量接近哺乳期妇女的推荐摄入量（11mg），但由于母乳中锌含量低，拉脱维亚的婴儿可能无法获得足够的锌摄入。未来的研究应通过评估母亲和婴儿的血浆或血清水平来评估锌状况。
