Alpha‐tocopherol stereoisomer profiles of lactating women supplemented with natural and synthetic vitamin E
Authors: Gaur Shashank , Sherry Christina 
Published: November 2023

Vitamin E is an essential nutrient during lactation for both maternal and infant health. Almost all dietary supplements contain synthetically manufactured vitamin E (all‐rac‐alpha‐tocopherol), which is known to have around half the bioactivity as of natural vitamin E (RRR‐alpha‐tocopherol), obtained from plant sources. Source of supplement (synthetic vs. natural) is known to influence the status, distribution and bioavailability of dietary vitamin E; however its influence on alpha‐tocopherol stereoisomer profile is poorly understood. This study systematically assessed the impact of synthetic (101.2 IU all‐rac‐alpha‐tocopherol) and natural (50.6 IU RRR‐alpha‐tocopherol) vitamin E supplementation on individual stereoisomers in breast milk and maternal plasma of fifty‐two lactating women, randomized in two supplement groups (synthetic and natural). Breast milk and maternal plasma were analyzed for total alpha‐tocopherol and individual stereoisomers at baseline and 6 week post supplementation, using high performance liquid chromatography. There was no significant change in total alpha‐tocopherol content over time and among treatment groups at either visit. RRR was the most abundant stereoisomer followed by RRS in both treatment groups during the study. In the synthetic supplement group, the proportion of RRR in breast milk decreased over six weeks (76 vs. 57.5%; P<0.001), whereas proportion of other stereoisomers increased (RRS 16 vs. 16.9%, RSR 3.5 vs. 9.5%; P<0.001, RSS 3.6 vs. 8.6%; P<0.001 and 2S 0.8 vs. 7.5%; P<0.001). Similarly, the proportion of RRR in maternal plasma decreased (80 vs. 59%; P<0.001), with subsequent increase in other stereoisomers (RRS 11.5 vs. 15%; P<0.001, RSR 4 vs. 10%; P<0.001, RSS 3.6 vs. 9%; P<0.001 and 2S 0.8 vs. 7%; P<0.001) over time. Natural vitamin E supplementation increased the proportion of RRR over six weeks (77.7 vs. 82.5%; P<0.001) in breast milk with a decrease in proportion of other stereoisomers (RRS 13.7 vs. 11.4%, RSR 4.3 vs. 3%; P<0.05, RSS 3.3 vs. 2.1%; P<0.05 and 2S 0.9 vs. 1%). Maternal plasma demonstrated a similar change with the natural supplement, and the proportion of RRR stereoisomer increased (77.5 vs. 86.7%; P<0.001), with a decrease in proportion of other stereoisomers (RRS 11.7 vs. 8.1%; P<0.001, RSR 5 vs. 2.5%; P<0.001, RSS 4.4 vs. 2%; P<0.001 and 2S 1.4 vs. 0.9%) over time. Total 2R: RRR ratio in breast milk and maternal plasma increased with synthetic supplement and decreased with the natural supplement over 6 weeks. There was a significant correlation (P<0.0001) between breast milk and maternal plasma stereoisomers, in both natural and synthetic groups, after six weeks of supplementation. In conclusion, Vitamin E supplement source (natural or synthetic) significantly impacts the profile and distribution of alpha‐tocopherol stereoisomers in lactating women. Any change in the native stereoisomer profile of breast milk and maternal plasma via supplementation may influence maternal and infant's nutrient adequacy during lactation.

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