2018—2019年中国六地区成熟母乳中维生素E含量及组成

Contents and isomers distribution of vitamin E in human mature breast milk from six regions of China in 2018-2019

目的研究中国不同地区成熟母乳中维生素E含量及异构体组成。方法在上海、广州、天津、成都、兰州、长春6个地区多中心同步招募604名乳母,年龄(29.58±3.43)岁,初产妇407名(67.38%),阴道分娩335名(55.46%),大专及以上学历493名(81.62%)。604例成熟母乳用高效液相色谱测定α-、γ-、δ-生育酚含量及α-生育酚的立体异构体组成(天然RRR和合成构型)。结果以M(P25,P75)表示,中国六地区成熟母乳α-生育酚含量水平为3.16(2.29,4.16)mg/L,RRR-α-生育酚为2.57(1.77,3.48)mg/L,γ-生育酚为0.89(0.58,1.27)mg/L,δ-生育酚为0.17(0.09,0.27)mg/L,提供活性α-生育酚当量为3.09(2.22,4.10)mg/L,地区差异有统计学意义(P<0.001)。成熟母乳中RRR-α-生育酚占总α-生育酚的比例为83.17%(76.36%,88.43%),其中天津地区成熟母乳RRR占比(77.11%)显著低于兰州(86.16%,P<0.001),其他地区差异无统计学意义(82.82%~85.39%)。结论在中国六地区成熟母乳中,维生素E主要由α-生育酚组成,虽然其含量存在地区差异,但均高度富集天然RRR形式,提示RRR-α-生育酚是生命早期维生素E主要活性形式。

OBJECTIVE The study aimed to investigate the contents and isomer composition of vitamin E in mature milk in different regions of China.METHODS Simultaneously recruited 604 lactating mothers aged(29.58±3.43)from Shanghai,Guangzhou,Tianjin,Chengdu,Lanzhou and Changchun cities.They were mainly primiparas with good education background.A total number of 604 mature milk samples was collected.The contents ofα-,γ-,δ-tocopherols and the stereoisomers ofα-tocopherol were determined by high performance liquid chromatography(HPLC).RESULTS The M(P25,P75)concentrations ofα-tocopherol,RRR-α-tocopherol,γ-tocopherol andδ-tocopherol in Chinese mature milk were 3.16(2.29,4.16)mg/L,2.57(1.77,3.48)mg/L,0.89(0.58,1.27)mg/L and 0.17(0.09,0.27)mg/L,respectively.The totalα-TE level was 3.09(2.22,4.10)mg/L with statistically regional differences(P<0.001).RRR-α-tocopherol was the predominated stereoisomers ofα-tocopherol,accounting for 83.17%(76.36%,88.43%).The proportion of RRR in Tianjin mature milk was significantly lower than that in Lanzhou(77.11%vs.86.16%,P<0.001)while breast milk samples from other regions had similar RRR-α-tocopherol proportions(82.82%-85.39%).CONCLUSION Vitamin E content in mature milk was mainly composed ofα-tocopherol.Even though the contents of tocopherols have large regional differences,RRR-α-tocopherol was predominated form in all breast milk samples.It is suggested that RRR-α-tocopherol was the main active form of vitamin E in the early stage of life.