Fundamentals of Human Nutrition/Vitamin C
8.8 Vitamin C
These are the colorful and raw fruits and vegetables that contain more vitamin C: red pepper, orange, lemon, grapefruit, cantaloupe, raspberries, strawberries, broccoli, tomatoes, etc..
|Dried Goji Berry||148|
|Sweet red pepper
Vitamin C is Very fragile, it is destroyed on contact with air (oxidation) or exposure to light (ultraviolet action) and heat accelerates the process. The heat of cooking destroys vitamin C. Vitamin C is destroyed between 60 and 75 ° C. Generally, consumption of at least 5 servings of fruits and vegetables allows filling largely recommended dietary in vitamin C.
Vitamin C is an hydrosoluble vitamin. This vitamin is sensitive to heat and light, and play an important role in the human metabolism. Chemically, it is the L-ascorbic acid, one of the stereoisomers of ascorbic acid and its salts, ascorbate (the most common being sodium ascorbate and calcium ascorbate). Vitamin C is an enzyme cofactor involved in a number of physiological reactions (hydroxylation). It is required in the synthesis of collagen and red blood cells and helps the immune system. It also plays a role in iron metabolism as absorption promoter and its use is therefore not recommended in patients with iron overload and particularly hemochromatosis. Oxidized form (dehydroascorbic acid), it crosses the blood-brain barrier to reach the brain and multiple organs with high concentrations of vitamin C. It is an antioxidant molecule that can counteract the harmful effects of oxidants such as free radicals. For this purpose, we also used the D-(-) (levogyre) of ascorbic acid, which, unlike the L-form (+) (Dextrogyre) has no vitamin activity. Vitamin C is also known as dehydroascorbic acid or ascorbic acid. It acts as an antioxidant in the body that helps to protect cells from being damaged, mainly by free radicals. Free radicals are compounds in the body that are formed when we convert our food into energy and can also be found in air pollution, cigarette smoke, and UV light . The buildup of free radicals in the body over time is partly responsible for the aging process. Vitamin C plays a role in the regeneration of other antioxidants such as vitamin E. The body is not capable of making vitamin C and it is also not able to store it either. That is why it is very important to make sure to include enough foods containing vitamin C in a diet. Vitamin C aids the body in the production of collagen, a protein that helps heal wounds and gives structure to muscles and other tissues. Vitamin C also aids the body in the absorption of iron from foods that are plant based. It also makes sure that the immune system is working properly in terms of protecting the body from disease. Another major role of vitamin C in the body is to repair and maintain bones, teeth, and cartilage. This is apparent in people with scurvy, a major vitamin C deficiency, because they are usually very weak and have little to no teeth at all. Vitamin C is also useful in the metabolism of some bile acids which may have implications for gallstones and blood-cholesterol levels . For a long time vitamin C has been used to cure or prevent the common cold. However, research shows that vitamin C does not reduce the risk of getting a cold. People who regularly take supplements of vitamin C might have slightly shorter colds or more mild symptoms. It can also act as an inhibitor of histamine, a compound that is released during allergic reactions. It has also been found to decrease or prevent the forming of possibly carcinogenic nitrosamines within the stomach . Vitamin C is also important in the eyes ability to deal with oxidative stress. It has been shown to delay the progression of age related vision loss and macular degeneration. Overall, vitamin C has a broad range of functions throughout the body and is an extremely important part of the diet. In a nutshell, the overall functions of vitamin C include immune stimulation, anti-allergenic, eye health, iron absorption, teeth and gum health, would healing, antioxidant, and collagen production.
European guidelines advise a daily intake of 75 mg for women and 90 mg for men. For example, an orange give an average of 53 mg of vitamin C (40 to 80 mg per 100 g). The North American Dietary Reference Intake recommends 90 milligrams per day and no more than 2 grams (2,000 mg) per day. The people who is exposing to the harmful effects of oxidants, such as smokers have an increased need for vitamin C. Some scientists like Linus Pauling (Nobel Prize in Chemistry in 1954), consider that the recommended dietary intake should be at least 6000mg, or 18 000mg .
A major deficiency of vitamin C, very rare, causes scurvy, when the supply is less than 10 mg per day. The more discreet hypovitaminosis are widespread and result in fatigue, weight loss, headache, bone pain, increased susceptibility to infections and sometimes bleeding problems .
Symptoms of deficiency in this area are rare. There are several common signs of Vitamin C deficiency that can be observed. It includes anemia, which is the lack of adequate red blood cells or in some cases hemoglobin in the blood, gingivitis, bleeding gums, failure to overcome infections and a slower healing rate, more frequent bruising, increase in weight, rough and scaly skin, inflamed joints, and the weakening of tooth enamel.
In extreme and rare circumstances a lack of vitamin C leads to Scurvy or atherosclerosis. Scurvy is a disease most commonly found in older adults, and consists of the degradation of all joints, tendons, and blood vessels. Ultimately, this leads to vessel erupting, hemorrhages, and organ failure. This is due to the lack of collagen protein and connective tissue in the body that is formed majorly through vitamin C.
Atherosclerosis is a condition where the body’s arteries are progressively filled with hardening plaque in arteries and blood vessels ultimately closing in the arteries and preventing oxygen flow throughout the body. 
Linus Pauling Theory
Linus Pauling, American scientist and recipient of two Nobel Prizes, proposed that heart disease could be treated and by increasing vitamin C intake. He hypothesized and found that heart disease was another form of scurvy and the plaque that gradually builds up in the body’s arteries and blood vessels were formed to help the body heal those vessels.
Antioxidants and Redox Signaling
In the study Antioxidants and Redox Signaling, researchers looked into how deficiencies in vitamin C led to severe damage in developing brains and motor behaviors. They theorized that the speed of the brain developing would be affected by the lack of an antioxidant system, which vitamin C contributes greatly to. After testing neonatal Gulo mice, the results showed that without vitamin C, growth was at a significantly lower rate and many brain deficiencies including a delay in the formation of cerebral fissures, abnormalities in areas such as the cerebellum and hippocampus, and a change in purkinje cells. The change in purkinje cells led to mice facing a decline in their overall motor skills. The researchers concluded that in new born babies vitamin C deficiencies cause hemorrhages and cerebellum defects. This deficiency also leads to damage in the cerebellum in individuals with full developed brains, including basic function impairment.
To resolve and avoid these vitamin C deficiencies one should increase their daily intake to the Recommended Dietary Allowances (RDA) preferred amount.
Vitamin C is not toxic at doses usually absorbed for a healthy individual. Since its synthesis in the 1930s, vitamin C is used at all doses throughout the world. The only side effects associated with its use and that are developed are mild diarrhea and diuretic action. These occur when consumed too quickly and too much. The body can not store it, it eliminates excess. Clinical studies show:
- the consumption of vitamin C does not increase  · · and even reduces  the incidence of kidney stones.
- that vitamin C has no mutagenic effect (study of doses up to 5000 mg per day)  ·.
In vivo studies show that vitamin C, even in the presence of transition metals has no mutagenic effect and instead it protects the cells of the mutagenic action of hydrogen peroxide .
Symptoms of an overdose of vitamin C may include: nausea, vomiting, headache, rash, and asthenia  . For doses greater than 500 mg/day , an increase of production of oxalic acid could induce a risk of kidney stones oxalate. This side effect is controversial in some studies. Indeed, plants that provide vitamin C also bring oxalate , hence the confusion.
Vitamin C: 8.8.5 Toxicity Vitamin C is rather an uncommon vitamin to overdose on, especially from its natural foods. Vitamin C toxicity normally occurs due to taking too many supplements. Vitamin C Toxicity cannot lead to death though and anything above the recommended amount of 2,000 mg of Vitamin C can lead to the below symptoms. The common symptoms that can occur from Vitamin C toxicity are:
- Abdominal Bloating and cramps
- Kidney Stones
Diarrhea Consuming more than 2000 mg of the recommended intake of Vitamin C can lead to irritation of the gastrointestinal tract that can lead to diarrhea and also vomiting can occur as well. As a result of the toxicity causing diarrhea and vomiting, one can lose a significant amount of fluids leading to dehydration, fatigue, low urine discharge and a reduction in blood pressure. Vitamin C’s effects on other minerals
Cooper: Pink eye or inflammation of the eyelids is caused by copper deficiency. When consuming too much vitamin C, which leads to a huge increase in high ascorbic, coupled with copper deficiency in the body can either cause the inflammation or make it worse. Chronic conjunctivitis, also known as pink eye, can occur due to Vitamin C toxicity depleting the cooper storage quickly.
Zinc: Vitamin C within the body has direct effects on Zinc and Zinc indirectly affects Iron. As a result a high Vitamin C toxicity would lead to worsened liver conditions, benign prostatic hypertrophy, or kidney diseases. Manganese: Large intake of Vitamin C can lead to insulin spikes which can affect people with hypoglycemic tendencies and have low sodium. Vitamin C toxicity can also affect the length of a woman's menstrual cycle because manganese has control over the liver’s ability to break down estrogen.
Kidney Stones: A substance in our body called oxalate breaks down Vitamin C and when we urinate, we secrete some oxalate. High urinary oxalate levels can build up causing deposits which are also known as kidney stones. Vitamin C toxicity is correlated with increased risk of kidney stones, and about 80 percent of all kidney stones are caused by Vitamin C toxicity.
Hemochromatosis: Hemochromatosis is a condition caused by excess iron build-up in the body. Within our body, Vitamin C helps absorb iron, and while Vitamin C toxicity does not cause Hemochromatosis, it can worsen the condition.
Work Citation Micronutrient Information Center. (n.d.). Retrieved December 1, 2015, from http://lpi.oregonstate.edu/mic/vitamins/vitamin-C Ohno, S., Ohno, Y., Suzuki, N., Soma, G., & Inoue, M. (n.d.). High-dose Vitamin C (Ascorbic Acid) Therapy in the Treatment of Patients with Advanced Cancer. Retrieved December 1, 2015, from http://ar.iiarjournals.org/content/29/3/809.long Vitamin C - All - Health Encyclopedia. (n.d.). Retrieved December 1, 2015, from https://www.kaahe.org/health/en/913-vitamin-c/all.html Vitamin C Supplementation. (n.d.). Retrieved December 1, 2015, from http://www.acu-cell.com/vitc.html Zeratsky, K. (n.d.). Nutrition and healthy eating. Retrieved December 1, 2015, from http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/vitamin-c/faq-20058030
- [English, J. (n.d.). Vitamin C, Colds and Acute Induced Scurvy. Retrieved November 27, 2015, from http://nutritionreview.org/2013/04/vitamin-colds-acute-induced-scurvy/]
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- [Vitamin C. (n.d.). Retrieved December 1, 2015, from https://ods.od.nih.gov/factsheets/VitaminC-Consumer/]
- Pauling, Linus. My Love Affair with Vitamin C
- Pharamacorama - L'acide ascorbique ou vitamine C
- Evert, A. (n.d.). Vitamin C. Retrieved August 11, 2015, from http://seotest.ga/seo--www.nlm.nih.gov/medlineplus/ency/presentations/100001_1.htm
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- Intake of vitamins B6 and C and the risk of kidney stones in women. Curhan GC, Willett WC, Speizer FE, Stampfer MJ. J Am Soc Nephrol. 1999 Apr;10(4):840-5.
- No contribution of ascorbic acid to renal calcium oxalate stones. Gerster H. Ann Nutr Metab. 1997;41(5):269-82.
- A prospective study of the intake of vitamins C and B6, and the risk of kidney stones in men. Curhan GC, Willett WC, Rimm EB, Stampfer MJ. J Urol. 1996 Jun;155(6):1847-51.
- Ascorbic acid and kidney stones. Hoffer A. Can Med Assoc J. 1985 Feb 15;132(4):320.
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- Suh J, Zhu BZ, Frei B (May 2003). "Ascorbate does not act as a pro-oxidant towards lipids and proteins in human plasma exposed to redox-active transition metal ions and hydrogen peroxide". Free Radic. Biol. Med. 34 (10): 1306–14. PMID 12726918.