Compendium of the most significant studies with reference to properties, intake, effects.

Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017 Nov 3;9(11):1211. doi: 10.3390/nu9111211.

Abstract. Vitamin C is an essential micronutrient for humans, with pleiotropic functions related to its ability to donate electrons. It is a potent antioxidant and a cofactor for a family of biosynthetic and gene regulatory enzymes. Vitamin C contributes to immune defense by supporting various cellular functions of both the innate and adaptive immune system.

Bucher A, White N. Vitamin C in the Prevention and Treatment of the Common Cold. Am J Lifestyle Med. 2016 Feb 9;10(3):181-183. doi: 10.1177/1559827616629092.

Abstract. The purpose of this article is to review the current data on the relationship between vitamin C and immune function, specifically, the utility of vitamin C supplementation in the prevention and treatment of the common cold.

Linowiecka K, Foksinski M, Brożyna AA. Vitamin C Transporters and Their Implications in Carcinogenesis. Nutrients. 2020 Dec 18;12(12):3869. doi: 10.3390/nu12123869.

Abstract. This review discusses the potential effects of vitamin C and the impaired SVCT function in cancers. The variations in vitamin C transporter genes may regulate the active transport of vitamin C, and therefore have an impact on cancer risk, but further studies are needed to thoroughly elucidate their involvement in cancer biology.

Hemilä H. Vitamin C and Infections. Nutrients. 2017 Mar 29;9(4):339. doi: 10.3390/nu9040339.

Abstract. In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. 

Marik PE. Vitamin C for the treatment of sepsis: The scientific rationale. Pharmacol Ther. 2018 Sep;189:63-70. doi: 10.1016/j.pharmthera.2018.04.007.

Abstract. Sepsis is associated with an acute deficiency of vitamin C. In experimental sepsis models, intravenous vitamin C reduces organ injury and improves survival. In addition, emerging evidence suggests that the combination of vitamin C, corticosteroids and thiamine may act synergistically to reverse sepsis induced organ dysfunction. 

Wang K, Jiang H, Li W, Qiang M, Dong T, Li H. Role of Vitamin C in Skin Diseases. Front Physiol. 2018 Jul 4;9:819. doi: 10.3389/fphys.2018.00819. 

Abstract. In this review, we will summarize the effects of vitamin C on four skin diseases (porphyria cutanea tarda, atopic dermatitis, malignant melanoma, and herpes zoster and postherpetic neuralgia) and highlight the potential of vitamin C as a therapeutic strategy to treat these diseases, emphasizing the clinical application of vitamin C as an adjuvant for drugs or physical therapy in other skin diseases.

Tada A, Miura H. The Relationship between Vitamin C and Periodontal Diseases: A Systematic Review. Int J Environ Res Public Health. 2019 Jul 11;16(14):2472. doi: 10.3390/ijerph16142472. 

Abstract. Vitamin C is important for preventing and slowing the progression of many diseases. There is significant evidence linking periodontal disease and vitamin C. We aimed to systematically review the studies addressing the relationship between vitamin C and periodontal disease, and the preventive ability of vitamin C against periodontal disease. 

Carr AC, McCall C. The role of vitamin C in the treatment of pain: new insights. J Transl Med. 2017 Apr 14;15(1):77. doi: 10.1186/s12967-017-1179-7. 

Abstract. Herein we propose a novel analgesic mechanism for vitamin C; as a cofactor for the biosynthesis of amidated opioid peptides. It is well established that vitamin C participates in the amidation of peptides, through acting as a cofactor for peptidyl-glycine α-amidating monooxygenase, the only enzyme known to amidate the carboxy terminal residue of neuropeptides and peptide hormones.

Van der Velden U. Vitamin C and Its Role in Periodontal Diseases - The Past and the Present: A Narrative Review. Oral Health Prev Dent. 2020;18(1):115-124. doi: 10.3290/j.ohpd.a44306.

Abstract. In humans, ascorbic acid, better known as vitamin C, is a true vitamin because humans lack the ability to synthesise it. Vitamin C exhibits a number of enzymatic and non-enzymatic effects but all are accounted for by the ability of vitamin C to donate electrons and therefore acts as a reducing agent. It has a wide range of functions. 

 Plevin D, Galletly C. The neuropsychiatric effects of vitamin C deficiency: a systematic review. BMC Psychiatry. 2020 Jun 18;20(1):315. doi: 10.1186/s12888-020-02730-w. 

Abstract. Vitamin C deficiency may be more common than is generally assumed, and the association between vitamin C deficiency and adverse psychiatric effects has been known for centuries. This paper aims to systematically review the evidence base for the neuropsychiatric effects of vitamin C deficiency.

Vitamin C  is a water-soluble, antioxidant vitamin  that must be consumed from external sources (mainly fruits and vegetables) because humans cannot synthesize it endogenously, whereas some animals can. From a health perspective, however, while dietary vitamin C from food has a protective association from early atherosclerosis, unfortunately, taking vitamin C supplements has an adverse association (1).

Vitamin C is is a simple low molecular weight carbohydrate and is necessary for tissue growth and repair in all parts of the body. The United States Institute of Medicine recommends a daily vitamin C intake of 75 milligrams per day for adult women and 90 milligrams per day for adult men.

Vitamin C studies

It is used for:

• Create an important protein for skin, tendons, ligaments and blood vessels.
• Heal wounds and scars.
• Repair and maintain healthy cartilage, bones and teeth.

Vitamin C is one of many antioxidants. Antioxidants are nutrients that block some of the damage caused by free radicals.

Free radicals are formed when the body is in particular conditions, for example when it is exposed to smoke or radiation, when you eat too much saturated fat, etc.

The accumulation of free radicals over time is largely responsible for the aging process.

Free radicals can play a role in cancer, heart disease and arthritis.

It is used for the maintenance of the antioxidant defenses of the cell, is a scavenger of free radicals. It also performs the important function of contributing to vitamin E regeneration. Vitamin C also cycles between an oxidized form (L-dehydroascorbic acid) and a reduced form (L-ascorbic acid). In addition, vitamin C is important for the absorption and metabolism of iron.

The body is unable to produce vitamin C on its own and does not store it. It is therefore important to take a certain amount of vitamin C with the foods that contain it, daily.

Used in the treatment of colds and flu.

It is located for exemple in:

• Citrus fruits and juices, such as orange, lemon, grapefruit
• Kiwi
• Mango
• Acerola
• Papaya
• Pineapple
• Strawberries, raspberries, blueberries, cranberries
• Watermelon

References________________________________________________________________________

(1) Agarwal M, Mehta PK, Dwyer JH, Dwyer KM, Shircore AM, Nordstrom CK, Sun P, Paul-Labrador M, Yang Y, Merz CN. Differing Relations to Early Atherosclerosis between Vitamin C from Supplements vs. Food in the Los Angeles Atherosclerosis Study: A Prospective Cohort Study. Open Cardiovasc Med J. 2012;6:113-21. doi: 10.2174/1874192401206010113. 

Abstract. Objective: To determine the relationship of vitamin c intake from supplements vs food on early atherosclerosis detected by carotid intima media thickness (IMT). Conclusions: Vitamin C supplementation is associated with accelerated early atherosclerosis measured by carotid IMT compared to a protective association with vitamin C from food. Theadverse association of vitamin C supplementation may be greater in patients with higher serum cholesterol levels. The current results provide a potential mechanistic understanding for the observed differences between Vitamin C in supplements vs food in prior studies. Given these observations,vitamin C supplementation does not appear to be currently advisable for prevention or treatment of atherosclerosis.

Sestili MA. Possible adverse health effects of vitamin C and ascorbic acid. Semin Oncol. 1983 Sep;10(3):299-304. PMID: 6364356.

Abstract. Consensus from individual studies and several review articles is that consumption of supplemental vitamin C leads to no significant adverse health effects to humans in general. Individuals who have a history of kidney stone formation and those who experience iron overload should exercise caution before using supplemental vitamin C. Occasionally, individuals experience diarrhea or mild nausea. There is also the possibility that vitamin C taken simultaneously with other drugs may contribute to adverse health effects and that its interference in clinical laboratory tests will mask diagnosis of disease. Few controlled clinical trials exist that conclusively demonstrate the adverse health effects that humans may experience with supplemental vitamin C usage, and before definite conclusions can be made of the health hazards to humans, more clinical trials are required.