Cited by 111Vitamin C and Antioxidants ResearchAntioxidant Activity and Oxidative StressPhytochemicals and Antioxidant Activities

Myths, Artifacts, and Fatal Flaws: Identifying Limitations and Opportunities in Vitamin C Research

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Michels, Alexander, Frei, Balz·2013·Nutrients

Abstract

Research progress to understand the role of vitamin C (ascorbic acid) in human health has been slow in coming. This is predominantly the result of several flawed approaches to study design, often lacking a full appreciation of the redox chemistry and biology of ascorbic acid. In this review, we summarize our knowledge surrounding the limitations of common approaches used in vitamin C research. In human cell culture, the primary issues are the high oxygen environment, presence of redox-active transition metal ions in culture media, and the use of immortalized cell lines grown in the absence of supplemental ascorbic acid. Studies in animal models are also limited due to the presence of endogenous ascorbic acid synthesis. Despite the use of genetically altered rodent strains lacking synthesis capacity, there are additional concerns that these models do not adequately recapitulate the effects of vitamin C deprivation and supplementation observed in humans. Lastly, several flaws in study design endemic to randomized controlled trials and other human studies greatly limit their conclusions and impact. There also is anecdotal evidence of positive and negative health effects of vitamin C that are widely accepted but have not been substantiated. 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.

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  • The low chemical stability of conventional vitamin C in the gastrointestinal tract necessitates an efficient delivery mode for vitamin C supplements.

    “Its low chemical stability in the gastrointestinal tract necessitates an efficient delivery mode for vitamin C supplements [13].”

    From Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults (2025) · cites this paper as [13]

    In §2.3.4, “Supplementing C: From Formulation to Dose” (page not provided), the paper says there is no evidence that different ascorbate formulations measurably affect vitamin C bioavailability in humans. The Human Studies section also reports nearly complete oral bioavailability at 200 mg/day. Its discussion of chemical instability concerns biological samples outside the body, not vitamin C in the gastrointestinal tract; the paper therefore does not support the claimed need for a special delivery mode. (LLM, conf=0.84)

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Research works printed but not linked: 1

  1. [3]Michels A.J. Frei B.B. Vitamin C Biochemical, Physiological, and Molecular Aspects of Human Nutrition 3rd ed. Stipanuk M.H. Caudill M.A. Elsevier/Saunders St. Louis, MO, USA 2012 626 654

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Authors
Michels, A., & Frei, B.
Affiliations
Oregon State University (US)
Corresponding author
Michels, Alexander
Venue
Nutrients
Publisher
MDPI AG
Published
2013-12-16
Volume
5
Issue
12
Pages
5161-5192
ISSN
2072-6643 (ISSN-L)
OpenAlex
W2076921574
Cited by
111
References
139
Citations by year
2026: 7 · 2025: 8 · 2024: 10 · 2023: 9 · 2022: 3 · 2021: 13 · 2020: 8 · 2019: 11 · 2018: 8 · 2017: 9 · 2016: 12 · 2015: 7 · 2014: 6
FWCI
0.94
Type
journal article
Language
en
Open access
Locations
  • Nutrients (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Topics
  • Health Sciences › Nursing › Nutrition and Dietetics › Vitamin C and Antioxidants Research
  • Health Sciences › Medicine › Biochemistry › Antioxidant Activity and Oxidative Stress
  • Health Sciences › Medicine › Biochemistry › Phytochemicals and Antioxidant Activities
Keywords
vitamin C, redox chemistry, transition metal ions, immortalized cell lines, ascorbic acid biosynthesis, vitamin C supplementation, randomized controlled trials
MeSH terms
Animals, Ascorbic Acid, Ascorbic Acid Deficiency, Disease Models, Animal, Humans, Randomized Controlled Trials as Topic, Dietary Supplements

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