title: Liposomal-encapsulated Ascorbic Acid: Influence on Vitamin C Bioavailability and Capacity to Protect Against Ischemia-Reperfusion Injury.
abstract: Intravenous administration of vitamin C has been shown to decrease oxidative stress and, in some instances, improve physiological function in adult humans. Oral vitamin C administration is typically less effective than intravenous, due in part to inferior vitamin C bioavailability. The purpose of this study was to determine the efficacy of oral delivery of vitamin C encapsulated in liposomes. On 4 separate randomly ordered occasions, 11 men and women were administered an oral placebo, or 4 g of vitamin C via oral, oral liposomal, or intravenous delivery. The data indicate that oral delivery of 4 g of vitamin C encapsulated in liposomes (1) produces circulating concentrations of vitamin C that are greater than unencapsulated oral but less than intravenous administration and (2) provides protection from ischemia-reperfusion-mediated oxidative stress that is similar to the protection provided by unencapsulated oral and intravenous administrations.
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Janelle L
authors.initials: JL
authors.lastname: Davis
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Hunter L
authors.initials: HL
authors.lastname: Paris
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Beals
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Binns
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Giordano
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Scalzo
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Melani M
authors.initials: MM
authors.lastname: Schweder
authors.affiliation: Empirical Labs, Fort Collins, Colorado, USA.; Nutritional Biomimetics LLC, Fort Collins, Colorado, USA.; Present address: Valimenta Labs, Fort Collins, Colorado, USA.
authors.forename: Emek
authors.initials: E
authors.lastname: Blair
authors.affiliation: Department of Health and Exercise Science, Colorado State University, Fort Collins, CO, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bell
keywords: intravenous; liposome; oral; oxidative stress; thiobarbituric acid reactive substances