TY - JOUR

T1 - On the effect of vitamin C intake on human health

T2 - How to (mis)interprete the clinical evidence

AU - Lykkesfeldt, Jens

N1 - Copyright © 2020 The Author. Published by Elsevier B.V. All rights reserved.

PY - 2020

Y1 - 2020

N2 - For decades, the potential beneficial effect of vitamin C on human health-beyond that of preventing scurvy-has been subject of much controversy. Hundreds of articles have appeared either in support of increased vitamin C intake through diet or supplements or rejecting the hypothesis that increased intake of vitamin C or supplementation may influence morbidity and mortality. The chemistry and pharmacology of vitamin C is complex and has unfortunately rarely been taken into account when designing clinical studies testing its effect on human health. However, ignoring its chemical lability, dose-dependent absorption and elimination kinetics, distribution via active transport, or complex dose-concentration-response relationships inevitably leads to poor study designs, inadequate inclusion and exclusion criteria and misinterpretation of results. The present review outlines the differences in vitamin C pharmacokinetics compared to normal low molecular weight drugs, focusses on potential pitfalls in study design and data interpretation, and re-examines major clinical studies of vitamin C in light of these.

AB - For decades, the potential beneficial effect of vitamin C on human health-beyond that of preventing scurvy-has been subject of much controversy. Hundreds of articles have appeared either in support of increased vitamin C intake through diet or supplements or rejecting the hypothesis that increased intake of vitamin C or supplementation may influence morbidity and mortality. The chemistry and pharmacology of vitamin C is complex and has unfortunately rarely been taken into account when designing clinical studies testing its effect on human health. However, ignoring its chemical lability, dose-dependent absorption and elimination kinetics, distribution via active transport, or complex dose-concentration-response relationships inevitably leads to poor study designs, inadequate inclusion and exclusion criteria and misinterpretation of results. The present review outlines the differences in vitamin C pharmacokinetics compared to normal low molecular weight drugs, focusses on potential pitfalls in study design and data interpretation, and re-examines major clinical studies of vitamin C in light of these.

U2 - 10.1016/j.redox.2020.101532

DO - 10.1016/j.redox.2020.101532

M3 - Review

C2 - 32535545

VL - 34

JO - Redox Biology

JF - Redox Biology

SN - 2213-2317

M1 - 101532

ER -