Department of Health and Nutrition, Osaka Shoin Women's University, Higashiosaka, Osaka 577-8550, Japan.
Division of Human Dietics, Graduate School of Human Science, Osaka Shoin Women's University, Higashiosaka, Osaka 577-8550, Japan.
Nutrients. 2021 Feb 9;13(2):573. doi: 10.3390/nu13020573.
Breast milk is considered the optimal source of nutrition during infancy. Although the vitamin D concentration in human breast milk is generally considered poor for infants, vitamin D in breast milk is an important source for exclusively breastfed infants. Increases in vitamin D insufficiency and deficiency in lactating mothers may reduce vitamin D concentrations in breast milk. This study aimed to compare vitamin D and 25-hydroxyvitamin D (25OHD) concentrations in breast milk collected in 1989 and 2016-2017 and simultaneously analyze them with liquid chromatography-tandem mass spectrometry (LC-MS/MS); the association between the lifestyle of recent lactating mothers (2016-2017) and vitamin D status in human breast milk was also evaluated.
Lactating mothers were recruited from three regions of Japan in 1989 ( = 72) and 2016-2017 ( = 90), and milk from 3-4 months was collected in summer and winter. The samples were strictly sealed and stored at -80℃ until measurement. Breast milk vitamin D and 25OHD concentrations were analyzed by LC-MS/MS. Vitamin D intake, sun exposure, and sunscreen use of the lactating mothers in 2016-2017 were assessed.
Both vitamin D and 25OHD concentrations in breast milk were higher in the summer regardless of the survey year. Significantly lower vitamin D and 25OHD concentrations were observed in 2016-2017 compared with 1989 in summer, but no survey year difference was observed in winter. The stepwise multiple regression analyses identified season, daily outdoor activity, and suntan in the last 12 months as independent factors associated with vitamin D concentrations.
The results suggest that low vitamin D status in recent lactating mothers may have decreased vitamin D and 25OHD concentrations in breast milk compared with the 1980s. These results are helpful for developing public health strategies to improve vitamin D status in lactating mothers and infants.
母乳被认为是婴儿期最佳的营养来源。尽管人乳中的维生素 D 浓度通常被认为对婴儿来说较差，但母乳中的维生素 D 是纯母乳喂养婴儿的重要来源。哺乳期妇女维生素 D 不足和缺乏的增加可能会降低母乳中的维生素 D 浓度。本研究旨在比较 1989 年和 2016-2017 年采集的母乳中的维生素 D 和 25-羟维生素 D（25OHD）浓度，并同时采用液相色谱-串联质谱法（LC-MS/MS）进行分析；还评估了最近哺乳期母亲（2016-2017 年）的生活方式与母乳中维生素 D 状况之间的关系。
1989 年（n = 72）和 2016-2017 年（n = 90）从日本三个地区招募哺乳期母亲，在夏季和冬季采集 3-4 个月的乳汁。采集的样本严格密封并储存在-80℃直至测量。采用 LC-MS/MS 分析母乳中维生素 D 和 25OHD 浓度。评估了 2016-2017 年哺乳期母亲的维生素 D 摄入量、阳光暴露和防晒霜使用情况。
无论调查年份如何，夏季母乳中维生素 D 和 25OHD 浓度均较高。与 1989 年相比，2016-2017 年夏季维生素 D 和 25OHD 浓度明显降低，但冬季无调查年份差异。逐步多元回归分析确定季节、每日户外活动和过去 12 个月的晒黑是与维生素 D 浓度相关的独立因素。
研究结果表明，与 20 世纪 80 年代相比，近期哺乳期母亲维生素 D 状况较低，可能导致母乳中维生素 D 和 25OHD 浓度降低。这些结果有助于制定改善哺乳期母亲和婴儿维生素 D 状况的公共卫生策略。
