Vitamin A and D Absorption in Adults with Metabolic Syndrome versus Healthy Controls: A Pilot Study Utilizing Targeted and Untargeted LC-MS Lipidomics

Scope Persons with metabolic syndrome (MetS) absorb less vitamin E than healthy controls. It is hypothesized that absorption of fat-soluble vitamins (FSV) A and D-2 would also decrease with MetS status and that trends would be reflected in lipidomic responses between groups. Methods and Results Following soymilk consumption (501 IU vitamin A, 119 IU vitamin D-2), the triglyceride-rich lipoprotein fractions (TRL) from MetS and healthy subjects (n = 10 age- and gender-matched subjects/group) are assessed using LC-MS/MS. Absorption is calculated using area under the time-concentration curves (AUC) from samples collected at 0, 3, and 6 h post-ingestion. MetS subjects have approximate to 6.4-fold higher median vitamin A AUC (retinyl palmitate) versus healthy controls (P = 0.07). Vitamin D-2 AUC is unaffected by MetS status (P = 0.48). Untargeted LC-MS lipidomics reveals six phospholipids and one cholesterol ester with concentrations correlating (r = 0.53-0.68; P < 0.001) with vitamin A concentration. Conclusions The vitamin A-phospholipid association suggests increased hydrolysis by PLB, PLRP2, and/or PLA(2)IB may be involved in the trend in higher vitamin A bioavailability in MetS subjects. Previously observed differences in circulating levels of these vitamins are likely not due to absorption. Alternate strategies should be investigated to improve FSV status in MetS.

Automated summary

Individuals with metabolic syndrome (MetS) absorb less vitamin E compared to healthy controls. This study found that MetS subjects have significantly higher absorption of vitamin A, while the absorption of vitamin D-2 is less affected by MetS status. The association between phospholipids and vitamin A suggests that enzymes may play a role in the higher bioavailability of vitamin A in MetS subjects.