Researchers at the world famous Linus Pauling Institute claim many studies into the health benefits of vitamin C have produced flawed results due to incorrect research methods.
The researchers say research into vitamin C requires different practices from those used to study other vitamins and minerals and often lack a full appreciation of the redox chemistry and biology.
The research – Myths, Artifacts, and Fatal Flaws: Identifying Limitations and Opportunities in Vitamin C Research – published in the journal Nutrients, examined studies where “vitamin C research ‘failed’ due to methodological, experimental, or design flaws”.
The researchers see these flawed approaches as having held back understanding of the role of vitamin C in human health and produced results indicating that supplementation has no value or could even be harmful.
The researchers argue that participants in vitamin C supplementation research, and diet-related studies in general, are usually healthy individuals who already have adequate levels of the vitamin, and this negatively affects the statistical power of the study as supplementation will provide little or no benefit. They believe that subjects should be deficient in the vitamin for a study to find meaningful results.
Lead author Alexander Michels also pointed out that in cell culture experiments, often carried out in a high oxygen environment, vitamin C is unstable and can actually appear harmful. “Almost every animal in the world, unlike humans, is able to synthesize its own vitamin C and doesn’t need to obtain it in the diet, which makes it difficult to do any lab animal tests with this vitamin that are relevant to humans,” he added.
“Only with careful attention to study design and experimental detail can we further our understanding of the possible roles of vitamin C in promoting human health and preventing or treating disease,” the authors concluded.
