The natural occurring RRR-α-Tocopherol and Synthetic α-Tocopherol stereoisomers in maternal plasma, cord plasma and breast milk among six regions of China

Abstract

Abstract Objective: The study aimed to investigate RRR-α-Tocopherol and synthetic α-Tocopherol stereoisomers in maternal plasma, cord plasma and breast milk from different regions of China, providing a reference for further guidance on maternal diet and the potential need to supplement mothers with vitamin E. Methods: Two hundred and twenty-one sample sets from maternal plasma, cord plasma and three stages of milk (colostrum: 1-5 days after delivery; transitional milk：10-15 days; mature milk: 40-45 days) were collected longitudinally in six regions of Shanghai, Guangzhou, Tianjin, Chengdu, Lanzhou and Changchun. α-Tocopherol and the stereoisomers were determined by high performance liquid chromatography with a fluorescence detector. Results: In six regions of China, α-Tocopherol concentrations in maternal plasma and cord plasma were 15.38 mg/L, 2.12 mg/L and those of RRR were 13.17 mg/L and 1.82 mg/L respectively while those of synthetic α-Tocopherol were 2.21 mg/L and 0.30 mg/L respectively. As for the breast milk, they were 9.59 mg/L, 8.60 mg/L in colostrum; 3.68 mg/L, 3.23 mg/L in transitional milk; 3.01 mg/L, 2.47 mg/L in mature milk respectively. The RRR configuration accounted for more than 80% of α-Tocopherol in maternal plasma, cord plasma and breast milk. Overall, there were regional differences both in α-Tocopherol and RRR. There were significant correlations between α-Tocopherol and RRR in maternal plasma, cord plasma and milk (P=0.000). As well as negative correlations among α-Tocopherol, RRR and weight-related indicators, which refer to pre-gestation weight and BMI, pre-delivery weight and BMI and pregnancy weight gain, in almost all of samples. Conclusion: Although there were regional differences in RRR-α-Tocopherol concentrations, it was highly enriched both in maternal plasma and cord plasma. This study suggested that RRR-α-Tocopherol was the dominant configuration of α-Tocopherol and the main active form of vitamin E in the early life, guiding the rational supplement of pregnant women and the addition of α-Tocopherol in infant formula milk powder.