Vitamin E in fortified cow milk uniquely enriches human plasma lipoproteins

Background: Milk fat may contribute to atherogenesis in humans, Objective: We sought to offset the atherogenic potential of milk fat by add ing polyunsaturated fat and vitamin E to milk. Design: We measured plasma lipids, lipoproteins, and tocopherol and LDL oxi dation in normolipemic adults. In experiment I (n = 48), we compared delive ry of 100 mg all-rac-alpha -tocopheryl acetate/d in capsules, skim milk, an d 1%-fat milks containing soybean oil, milk fat, or both (1: 1). In experim ent 2 (n = 24), we compared delivery of natural (RRR-alpha -tocopheryl acet ate) and synthetic (all-rac-alpha -tocopheryl acetate) vitamin E in milk wi th delivery of all-rac-alpha -tocopheryl acetate in orange juice (200 mg/d in each group). In experiment 3 (n = 7), we compared delivery of 30 mg all- rac-alpha -tocopheryl acetate/d in milks with and without added vitamins A and D. Results: Enrichment of milk fat with soybean oil did not alter plasma lipop roteins. Microdispersion of vitamin E in milks increased the molar ratio of plasma tocopherol to cholesterol by >2-fold compared with the molar ratio after consuming vitamin E capsules, whereas the molar ratios were comparabl e after ingestion of orange juice and capsules. Synthetic and natural vitam in E performed comparably. The enhanced plasma vitamin E cholesterol attrib uted to milk increased protection of LDL against oxidation. Vitamins A and D did not affect vitamin E delivery by milk. Conclusions: Milk augments vitamin E transport by human lipoproteins at int akes of 100-200 but not 30 mg/d. This augmentation is independent of the pr esence and type of fat in milk, its vitamin A and D contents, and whether t he vitamin E is natural or synthetic.