Vitamin C-Beyond Deficiency: Mechanisms, Clinical Applications, Formulation and Dosing Considerations, and Safety...

Area of Science:

• Biochemistry
• Nutritional Science
• Clinical Medicine

Background:

• Vitamin C (L-ascorbic acid) is an essential micronutrient with diverse roles including collagen synthesis, immune function, and iron absorption.
• Vulnerability to low vitamin C status increases with trauma, surgery, inflammation, and other health conditions.
• Dietary reference values primarily aim to prevent deficiency in the general population.

Purpose of the Study:

• To review evidence on vitamin C as a stress-responsive micronutrient.
• To synthesize mechanistic, pharmacokinetic, clinical, and safety data across various health domains.
• To differentiate oral supplementation from intravenous administration and assess evidence strength.

Main Methods:

• Narrative review of existing literature.
• Synthesis of evidence across tissue repair, orthopedic recovery, fatigue, neuropsychiatric health, cancer care, vascular homeostasis, and dermatology.
• Analysis of pharmacokinetic and safety data for different administration routes and formulations.

Main Results:

• Biochemical functions and deficiency correction of vitamin C are well-established.
• Evidence for supraphysiologic oral vitamin C supplementation in replete individuals is uncertain and condition-specific.
• Intravenous administration differs significantly from oral routes regarding absorption and tolerance.

Conclusions:

• High-dose oral vitamin C supplementation should be individualized, time-limited, and clinician-monitored.
• Clinical value of vitamin C depends on baseline status, patient vulnerability, route, dose, and safety.
• Population-level recommendations for high-dose oral vitamin C are not supported by current evidence.