Rajalakshmi K, Srikantia S G
Am J Clin Nutr. 1980 Mar;33(3):664-9. doi: 10.1093/ajcn/33.3.664.
Copper, zinc, and magnesium contents were determined in samples of breast milk obtained from 412 women in a low income group, from 100 women in a high income group of an urban population, and from 22 women from a low income group living in a rural area. Paired samples of milk and serum were collected from 152 women and the concentrations of copper and zinc in these two fluids were estimated. Copper levels fell from 0.46 microgram/ml in colostrum to 0.17 microgram/ml at 7 to 12 months of lactation; zince levels fell from 5.32 to 1.12 microgram/ml by 7 months. Magnesium level in colostrum was 40 micrograms/ml and reached a stable level of around 30 micrograms/ml in mature milk samples. Concentrations of copper and zinc in serum were not correlated with those in milk. Day to day and diurnal variations in the concentrations of these elements in milk were not significant indicating thereby that analysis of one sample provides satisfactory information of the trace element content in milk. There were no differences in the levels of these elements in milk between rural and urban low income groups of women. However significant differences were noted in the copper and zinc contents of milk of women from low and high income groups of the urban population, from the 1st to 3rd month of lactation.
对来自低收入群体的412名女性、城市高收入群体的100名女性以及农村低收入群体的22名女性的母乳样本进行了铜、锌和镁含量的测定。从152名女性中采集了配对的母乳和血清样本，并估算了这两种液体中铜和锌的浓度。铜含量从初乳中的0.46微克/毫升降至哺乳期7至12个月时的0.17微克/毫升；锌含量到7个月时从5.32微克/毫升降至1.12微克/毫升。初乳中的镁含量为40微克/毫升，在成熟母乳样本中达到约30微克/毫升的稳定水平。血清中铜和锌的浓度与母乳中的浓度不相关。母乳中这些元素浓度的每日和昼夜变化不显著，这表明分析一个样本就能提供母乳中微量元素含量的满意信息。农村和城市低收入群体女性的母乳中这些元素的含量没有差异。然而，在城市人口中低收入和高收入群体女性的母乳中，从哺乳期第1个月到第3个月，铜和锌的含量存在显著差异。
