Determination of plasma and leukocyte ascorbate concentrations in a randomized, double‐blind trial (830.3)

Abstract

Plasma ascorbate reflects recent intake, whereas leukocyte ascorbate more closely reflects cellular stores and total body pool. Objective was to evaluate the bioavailability of ascorbate in plasma and leukocytes from a novel vitamin C formulation. In this double‐blind, cross‐over, males and females between 18‐60 years were randomized to receive one of the following: Placebo (P, 0mg vitamin C), Ascorbic Acid (AA, 1000mg vitamin C) or Ester‐C ® (EC, 1000mg vitamin C + threonate and furanone) as a single dosage. Plasma and leukocyte ascorbate were measured at 2, 4, 8, and 24 hours following treatment. An intention‐to‐treat analysis was conducted on thirty six subjects (18 males, 18 females). Plasma ascorbate percent change from Baseline was significantly higher for EC and AA at 2 hours compared to P (EC=135.55±176, AA=126.60±135, P=2.35±33; p<0.001). At 4, 8, and 24 hours the percent change from Baseline was only significantly higher for EC compared to P (all p蠄0.035). The percent change in leukocyte ascorbate was significantly higher from Baseline for EC at 2, 4, 8, and 24 hours (all p蠄0.041) and P at 4 and 24 hours (p蠄0.035) but there was no change from Baseline for the AA group. Vitamin C from Ester‐C and Ascorbic Acid has greater plasma bioavailability than Placebo. Compared to Baseline, Ester‐C ® provides a higher percent change in leukocyte ascorbate, which may be due to the presence of threonate and furanone in the formula.