“These findings are important because they are the first to demonstrate that coating a MVM supplement with liposomes can affect the pharmacokinectic (PK) profile of several vitamins and minerals within the MVM supplement and thereby influence nutrient bioavailability,” wrote researchers from the Exercise & Sport Nutrition Lab at Texas A&M University.
The study, published in the journal Nutrients, was funded by Salt Lake City-based Nutraceutical Corp. to verify results of the Energy Balance & Body Composition Laboratory at Texas Tech University using the same experimental design, supplements, time points and methods.
Liposomal encapsulation and multivitamins
Encapsulating nutrients in liposomes (spherical vesicles composed of one or more phospholipid bilayers) provides a protective barrier around a compound. This novel coating increases resistance to digestive enzymes, acidity, intestinal flora and oxidation to enhance intestinal absorption, delivery to specific tissues and bioavailability.
“While there is evidence that liposomal encapsulation of individual nutrients can affect nutrient absorption into the blood and/or delivery to tissues, less is known about whether liposomal encapsulation of a MVM supplement would affect the appearance and/or clearance of vitamins and minerals from the blood,” the study authors noted.
The first Texas Tech lab study, also funded through a Nutraceutical Corp. research grant, analyzed changes in iron and magnesium plasma concentrations, determining that only iron absorption from an MVM product was enhanced by a liposomal delivery mechanism.
Researchers at the Texas A&M lab used a crossover, double-blind, placebo-controlled study design and randomly assigned 34 healthy men and women to one of two groups that either consumed a non-liposomal or liposomal MVM supplement manufactured by Nutraceutical Corp., taken with a standardized snack after a 12-hour fast.
Venous blood samples were obtained at baseline and at 2, 4, and 6 hours after MVM ingestion and analyzed for a panel of vitamins and minerals. The primary outcome was serum vitamin levels and area under the curve measures, with comprehensive pharmacokinetic analysis variables as secondary outcome.
The researchers found an overall treatment effect change over time among the vitamins and minerals evaluated. They also reported differences between treatments in volume distribution area (vitamin E, iron), median residence time (vitamin E, iron), volume distribution area (iron), volume of distribution steady state (vitamin A, E, iron), clearance rates (vitamin A, E), elimination phase half-life (vitamin E, iron), distribution/absorption phase intercept (vitamin A), and distribution/absorption phase slope and rate (vitamin C, calcium). Vitamin volume distribution was lower in the liposomal MVM group, suggesting greater clearance and absorption.
“With additional research, this may serve as a more efficient way to deliver vitamins and minerals in dietary supplements,” the researchers concluded. “However, additional research is needed to determine the impact of coating a MVM supplement with liposomes on tissue uptake, metabolic function and health.”
For further study, they also suggested liposomal encapsulation of individual vitamins and minerals within the MVM supplement and investigating the effects of long-term supplementation with liposomal MVM supplements on vitamin and mineral status, nutrient function and health outcomes.
“Pharmacokinetic Analyses of Liposomal and Non-Liposomal Multivitamin/Mineral Formulations”
Authors: Joungbo Ko et al.