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| [[File:Vitamin c (8399032152).jpg|thumb|Vitamin C]] | | #REDIRECT [[Chemistry of ascorbic acid]] |
| [[File:L-Ascorbic acid.svg|L-Ascorbic_acid|thumb]]
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| [[File:Vitamin C 2.jpg|Vitamin C|thumb]]
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| [[File:Vitamin C (1989 calendar march).jpg|Vitamin C|thumb]]
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| '''Vitamin C''', also known as '''ascorbic acid''', is an essential nutrient for humans and various other animal species. It plays a crucial role in many physiological processes, including the synthesis of collagen, the absorption of iron, and the maintenance of a healthy immune system. This article will discuss the functions, dietary sources, recommended daily intake, deficiency, and supplementation of vitamin C.
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| == Functions ==
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| Vitamin C is a water-soluble vitamin that has several important functions in the human body:
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| * '''[[Collagen synthesis]]''': Vitamin C is necessary for the synthesis of collagen, a structural protein found in connective tissues, skin, and bones [^1^].
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| * '''[[Antioxidant]] activity''': As an antioxidant, vitamin C helps to neutralize free radicals, thereby reducing oxidative stress and protecting cells from damage [^2^].
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| * '''Immune system support''': Vitamin C contributes to the proper functioning of the immune system by supporting the production and function of white blood cells [^3^].
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| * '''[[Iron absorption]]''': Vitamin C enhances the absorption of non-heme iron from plant-based sources by reducing it to a more easily absorbed form [^4^].
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| == Dietary Sources ==
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| Vitamin C is found in a wide range of fruits and vegetables. Some of the best dietary sources of vitamin C include:
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| * [[Citrus fruits]] (e.g., [[oranges]], [[grapefruit]]s, [[lemon]]s, limes)
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| * [[Kiwifruit]]
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| * [[Strawberries]]
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| * [[Guava]]s
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| * [[Papaya]]s
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| * Pineapples
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| * [[Melons]]
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| * [[Mangoes]]
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| * [[Tomatoes]]
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| * [[Bell peppers]]
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| * [[Broccoli]]
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| * [[Brussels sprouts]]
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| * [[Leafy greens]] (e.g., spinach, kale, mustard greens)
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| * [[Cauliflower]]
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| * [[Cabbage]]
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| It is important to note that vitamin C is sensitive to heat and light, so cooking and storage methods can affect the nutrient content of these foods [^5^].
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| == Recommended Daily Intake ==
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| The recommended daily intake (RDI) of vitamin C varies depending on factors such as age, sex, and life stage. According to the National Institutes of Health (NIH), the following RDIs apply for vitamin C [^6^]:
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| * Infants (0-12 months): 40-50 mg/day
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| * Children (1-8 years): 15-25 mg/day
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| * Adolescents (9-18 years): 45-75 mg/day
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| * Adults (19+ years): 75-90 mg/day (additional 35 mg/day for smokers)
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| * Pregnant women: 80-85 mg/day
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| * Breastfeeding women: 115-120 mg/day
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| == Deficiency ==
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| Vitamin C deficiency, known as '''scurvy''', is relatively rare in developed countries but can still occur in individuals with inadequate dietary intake or poor absorption. Symptoms of scurvy include:
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| * Fatigue
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| * Muscle weakness
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| * Joint pain
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| * Swollen, bleeding gums
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| * Bruising easily
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| * Anemia
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| * Slow wound healing
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| Severe vitamin C deficiency can lead to serious health complications and even death if left untreated. Treatment involves the administration of vitamin C supplements or increasing dietary intake of vitamin C-rich foods [^7^].
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| == Supplementation ==
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| Vitamin C supplements are available in various forms, including tablets, capsules, chewable tablets, and effervescent tablets. Some individuals may choose to take vitamin C supplements to help meet their daily requirements, especially if they have difficulty obtaining sufficient amounts from their diet.
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| However, it is essential to note that excessive vitamin C intake can cause side effects, such as diarrhea, nausea, and stomach cramps. The NIH has established a tolerable upper intake level (UL) for vitamin C, which is the maximum daily intake unlikely to cause adverse health effects 1:
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| * Children (1-8 years): 400-650 mg/day
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| * Adolescents (9-18 years): 1,200-1,800 mg/day
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| * Adults (19+ years): 2,000 mg/day
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| * Pregnant and breastfeeding women (18 years and younger): 1,800 mg/day
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| * Pregnant and breastfeeding women (19 years and older): 2,000 mg/day
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| * It is generally recommended to obtain essential nutrients, including vitamin C, from a well-balanced diet rather than relying on supplements. However, if you are considering taking vitamin C supplements, it is best to consult a healthcare professional for personalized advice.
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| =='''Liver Safety of Ascorbic Acid'''==
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| There is no evidence to suggest that vitamin C, in physiologic or moderately high doses, causes acute liver injury or jaundice.
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| == Mechanism of Action ==
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| Vitamin C, also known as L-ascorbic acid, is a water-soluble vitamin. Its primary function is to act as an electron donor and intracellular antioxidant, protecting critical intracellular molecules and enzyme systems from reactive oxygen species. Additionally, vitamin C serves as a cofactor in various biochemical synthetic reactions, collagen cross-linking, the synthesis of neuropeptides and hormones, and non-heme iron absorption.
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| == Side Effects ==
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| Physiological and even excessive intakes of up to 2 grams daily have virtually no side effects. However, higher doses of vitamin C can cause diarrhea, nausea, abdominal discomfort, flushing, dizziness, and headache. These doses may also be associated with transient serum aminotransferase elevations.
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| == See Also ==
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| * [[Vitamins]]
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| * [[Vitamin A]]
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| * [[Vitamin D]]
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| * [[Vitamin E]]
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| * [[Vitamin K]]
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| == External Links ==
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| * [https://ods.od.nih.gov/factsheets/VitaminC-Consumer/ NIH Office of Dietary Supplements: Vitamin C]
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| * [https://www.hsph.harvard.edu/nutritionsource/vitamin-c/ Harvard T.H. Chan School of Public Health: Vitamin C]
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| * [https://www.medicalnewstoday.com/articles/219352 Medical News Today: Vitamin C: Why we need it]
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| * Footnotes: Institute of Medicine (US) Panel on Dietary Antioxidants and Related Compounds. (2000). Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. National Academies Press
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| {{stb}}
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| [[Category:Vitamins]]
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| [[Category:Nutrients]]
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| [[Category:Health]]
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