Marginal Ascorbate Status (Hypovitaminosis C) Results in an Attenuated Response to Vitamin C Supplementation.
Inadequate dietary intake of vitamin C results in hypovitaminosis C, defined as a plasma ascorbate concentration ≤23 μmol/L. Our objective was to carry out a retrospective analysis of two vitamin C supplementation studies to determine whether supplementation with 50 mg/day vitamin C is sufficient to restore adequate ascorbate status (≥50 μmol/L) in individuals with hypovitaminosis C. Plasma ascorbate data from 70 young adult males, supplemented with 50 or 200 mg/day vitamin C for up to six weeks, was analyzed. Hypovitaminosis C status was identified based on plasma ascorbate being ≤23 μmol/L and the response of these individuals to vitamin C supplementation was examined. Of the participants consuming 50 mg/day vitamin C for up to six weeks, those with hypovitaminosis C at baseline achieved plasma concentrations of only ~30 μmol/L, whereas the remainder reached ~50 μmol/L. Participants who consumed 200 mg/day vitamin C typically reached saturating concentrations (>65 μmol/L) within one week, while those with hypovitaminosis C required two weeks to reach saturation. Regression modelling indicated that the participants' initial ascorbate status and body weight explained ~30% of the variability in the final ascorbate concentration. Overall, our analysis revealed that supplementation with 50 mg/day vitamin C, which resulted in a total dietary vitamin C intake of 75 mg/day, was insufficient to achieve adequate plasma ascorbate concentrations in individuals with hypovitaminosis C. Furthermore, increased body weight had a negative impact on ascorbate status.
Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand. anitra.carr@otago.ac.nz.
Anitra C
AC
Carr
Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand. juliet.pullar@otago.ac.nz.
Juliet M
JM
Pullar
Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand. stephanie.bozonet@otago.ac.nz.
Stephanie M
SM
Bozonet
Department of Pathology, University of Otago, Christchurch, P.O. Box 4345, Christchurch 8140, New Zealand. margreet.vissers@otago.ac.nz.
Margreet C M
MC
Vissers
D000328:Adult; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology*; D001206:Ascorbic Acid Deficiency / Q000097:blood / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008297:Male
D001205:Ascorbic Acid
body weight; human intervention study; hypovitaminosis C; recommended dietary intake; vitamin C supplementation