Vitamin C/Vitamine C (ascorbic acid, calcium ascorbate, magnesium ascorbate, niacinamide ascorbate, sodium ascorbate, ascorbyl palmitate/acide ascorbique, ascorbate de calcium, ascorbate de magnésium, ascorbate de niacinamide, ascorbate de sodium, palmitate d'ascorbyle)
Also known as: Vitamin C, ascorbic acid, calcium ascorbate, magnesium ascorbate, niacinamide ascorbate, sodium ascorbate, ascorbyl palmitate, acide ascorbique, ascorbate de calcium, ascorbate de magnésium, ascorbate de niacinamide, ascorbate de sodium, palmitate d'ascorbyle, L-ascorbic acid
Overview
Vitamin C, or L-ascorbic acid, is a vital water-soluble vitamin and antioxidant involved in numerous physiological functions including collagen synthesis, immune response enhancement, and iron absorption. It is chiefly sourced from fruits and vegetables, especially citrus fruits, strawberries, bell peppers, and broccoli. Because the human body cannot synthesize Vitamin C, regular dietary intake is essential. Research has indicated that adequate Vitamin C levels can reduce the risk of various diseases, including cardiovascular conditions and certain cancers. Vitamin C supplements come in various forms, including ascorbic acid and its mineral salts like calcium ascorbate and sodium ascorbate, with varying implications for absorption and gastrointestinal tolerance. While Vitamin C has established benefits, ongoing research continues to explore its role in health and disease contexts.
Benefits
Vitamin C is associated with several health benefits supported by robust research. A daily intake increase of 50-100 mg is linked to a reduced risk of all-cause mortality and chronic diseases, particularly cardiovascular diseases and specific cancers (oesophageal and gastric) (Evidence level: Strong). In critically ill patients, supplementation may shorten the duration of mechanical ventilation (Evidence level: Moderate). Notably, Vitamin C supplementation shows promise in enhancing immune function, although results are mixed regarding its efficacy in cold prevention and treatment. Research supports Vitamin C’s effects on multiple health domains, including respiratory and neurological health, with varying effect sizes. Regular intake over time may yield significant health benefits, particularly for at-risk populations, such as the elderly and those with chronic health conditions.
How it works
Vitamin C functions primarily as a potent antioxidant, scavenging free radicals and reducing oxidative stress in the body. It plays an essential role in collagen biosynthesis by hydroxylating proline and lysine residues in connective tissues. Furthermore, Vitamin C enhances immune responses by promoting the proliferation and activity of lymphocytes (white blood cells). It improves iron absorption from the gastrointestinal tract, converting dietary iron into a more absorbable state. The bioavailability of Vitamin C decreases at high doses due to saturation of transport systems, indicating a need for regular, adequate dosing for optimal physiological benefit.
Side effects
Vitamin C is generally well tolerated, but high doses may lead to adverse effects in some individuals. Common side effects occurring in more than 5% of users include gastrointestinal upset, diarrhea, and stomach cramps, predominantly due to excess intake. Uncommon side effects, affecting 1-5% of users, may include kidney stones, particularly in individuals with predispositions to oxalate stone formation. Severe allergic reactions are rare (<1%). Caution is advised for individuals taking anticoagulants or with existing kidney conditions; high doses should be avoided in such populations. Pregnant or nursing women and individuals with a history of kidney stones should consult healthcare professionals before starting higher doses. By adhering to recommended dosages, the incidence of side effects is minimized.
Dosage
For general health, the minimum effective dose of Vitamin C is approximately 60 mg per day, while optimal intake ranges from 60 to 200 mg per day. The Tolerable Upper Intake Level (UL) for adults is set at 2,000 mg per day to avoid adverse gastrointestinal effects. Vitamin C is best absorbed when consumed alongside meals, which may enhance its bioavailability. The absorption of Vitamin C can be diminished at higher doses due to saturation of transporters. Different forms, such as ascorbic acid or mineral ascorbates, may influence both absorption and tolerance. Regular and divided doses throughout the day can improve gastrointestinal tolerance and absorption efficiency. Cognitive and physiological benefits are most pronounced with consistent daily intake.
FAQs
Is Vitamin C effective for preventing colds?
Vitamin C may shorten the duration and severity of colds but does not prevent them outright.
Can I take high doses of Vitamin C?
While Vitamin C is generally safe, high doses can lead to gastrointestinal upset and increase the risk of kidney stones.
When is the best time to take Vitamin C?
Vitamin C is best taken with meals to enhance absorption and minimize gastrointestinal side effects.
What are the benefits of Vitamin C supplementation?
Vitamin C supplementation can improve immune function, enhance collagen synthesis, and reduce the risk of chronic diseases.
Is there a maximum dose I should stay under?
The Tolerable Upper Intake Level for Vitamin C is 2,000 mg per day for adults.
Research Sources
- https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1465670/full – This meta-analysis examines Vitamin C's effects on various health outcomes, highlighting its potential in reducing the risk of chronic diseases and improving overall health.
- https://younitedwellness.ca/pages/nutrition-information-ingredients – This resource outlines Vitamin C's importance, sources, and health benefits, providing a comprehensive overview of its role in nutrition.
- https://pubmed.ncbi.nlm.nih.gov/35291895/ – This study explores the implications of Vitamin C supplementation in critically ill patients, suggesting benefits in terms of reducing vasopressor use and mechanical ventilation duration.
- https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/ – The NIH fact sheet provides detailed information on Vitamin C, including its health benefits, dietary sources, recommended intake, and safety information.
- https://journals.lww.com/md-journal/fulltext/2024/03220/the_effects_of_vitamin_c_supplementation_in_the.70.aspx – This systematic review assesses the impact of Vitamin C supplementation in hospitalized patients, concluding it did not significantly affect mortality or ICU stays.