Vitamin C (ascorbic acid):

Vitamin C, also known as ascorbic acid, is a small water-soluble carbohydrate naturally found in some foods and can also be obtained as a dietary supplement. Vitamin C is well known for its antioxidant properties, which protect cells from free radicals that form during energy-producing reactions in the body or when exposed to various environmental factors such as sunlight. Vitamin C plays a crucial role in the formation of collagen, which is essential for skin, bones, and cartilage.

Benefits of Vitamin C:

There are many important biological functions of vitamin C in the body, including enzymatic and non-enzymatic reactions. Vitamin C's non-enzymatic reactions have given it its role as an important antioxidant that can reduce free radicals. Vitamin C also helps protect important cell components like DNA, proteins, and fats from oxidative damage. One of the well-known functions of vitamin C is its role in collagen synthesis. Vitamin C is commonly used for skin rejuvenation to promote collagen renewal. Vitamin C also stimulates physiological processes such as immune response, nerve transmission, energy metabolism, and relaxation of blood vessels. Vitamin C plays a crucial role at the genetic level, influencing the regulation of new blood vessel formation and cell proliferation.

Vitamin C deficiency:

The clinical manifestation of vitamin C deficiency is scurvy, a condition known for centuries through long sea voyages. If left untreated, scurvy can be fatal. Symptoms include wounds, gum inflammation, bleeding around the gums, bruises, discoloration, and delayed wound healing. Vitamin C deficiency is significantly associated with impaired collagen formation, specifically hydroxylase HIF-1a. Prolonged vitamin C deficiency can lead to other symptoms such as tightness, fatigue, lethargy, and mood disturbances (depression). Recent studies have linked chronic vitamin C deficiency to the development of chronic diseases such as cardiovascular diseases.

Those at risk of vitamin C deficiency:

1. Individuals following a diet rich in fats and carbohydrates but poor in fresh fruits and vegetables.
2. Smokers (active and passive).
3. Pregnant women.
4. Those with low socioeconomic status, genetic predisposition, and various conditions associated with cardiovascular regulation disorders such as high blood pressure, diabetes, severe obesity, some types of cancers, and kidney diseases requiring dialysis.
5. Individuals with normal malabsorption conditions, kidney disease patients, and those with large wounds such as burn victims.

Sources of vitamin C in food:

Most fruits and vegetables are rich sources of vitamin C. Fruits such as citrus fruits, kiwi, and mango are good sources of vitamin C along with their juices. Vegetables like peppers, cauliflower, and tomatoes are good sources as well. On the other hand, bananas, apples, and other staple foods are considered poor sources. It's important to note that heating and storage can lead to the destruction of vitamin C in food, reducing its content. Try to consume fresh vegetables and fruits to maximize their benefits.

Recommended daily amounts of vitamin C globally:

The necessary dose of vitamin C depends on body mass. It is recommended to consume 75 mg/day for females and 90 mg/day for males. For pregnant and lactating women, the recommended amount is 85-120 mg/day for pregnant and lactating women (over 19 years old), respectively. For infants, it is recommended to take 40 mg/day for infants under 6 months and 50 mg/day for children between 6-12 months. The dosage for children depends on body mass, with recommendations of 15 mg/day for children under 3 years old and 45 mg/day for children under 13 years old. Adolescents are advised to consume 75-65 mg/day for males and females aged between 13 and 17 years. Smokers are recommended to take an additional 35 mg/day of vitamin C due to the toxicity of smoking.

Vitamin C toxicity:

Vitamin C is generally non-toxic and can be tolerated even in large doses. The allowed level of vitamin C is 2 grams/day. Recently, the upper limit of vitamin C dosage has been removed due to the lack of proven toxicity. Some individuals may experience temporary gastrointestinal disturbances such as diarrhea, nausea, and stomach cramps with higher doses of vitamin C. Large and chronic doses of vitamin C have been associated with kidney stone formation, but this link is not yet confirmed. Individuals at risk of kidney stones should avoid regular intake of vitamin C supplements. Excessive amounts of vitamin C can exacerbate iron overload and tissue damage in individuals with hemochromatosis.

Vitamin C and the common cold:

Large doses of vitamin C may help reduce the duration of the common cold but do not prevent its occurrence. Vitamin C may be effective in individuals undergoing high physical activity.

Vitamin C and cancer:

Individuals consuming high doses of vitamin C may have a lower risk of lung, colon, and breast cancer. However, vitamin C cannot prevent cancer development. High-dose vitamin C studies are ongoing, particularly through intravenous injection, which may shrink tumors. It is important to inform the doctor when undergoing chemotherapy or radiation therapy for cancer, as vitamin C or other antioxidants may interact with treatment, especially at high doses.

Relationship between Vitamin C and heart diseases:

Vitamin C has been observed to reduce the risk of cardiovascular diseases due to its antioxidant properties. However, there is no solid scientific evidence yet on the preventive role of vitamin C in heart and vascular diseases or its ability to help individuals already affected in reducing severity.

Vitamin C and Age-Related Macular Degeneration (AMD):

Vitamin C and other antioxidants help reduce the progression of AMD. Patients taking a certain dose of vitamin C play a role in preventing vision loss. Additionally, individuals receiving sufficient doses of vitamin C have a lower risk of developing cataracts.

Vitamin C and other medications:

1. Vitamin C supplements may interact with some chemotherapy and radiation treatments for cancer.
2. Vitamin C intake may reduce the body's response to certain anticoagulants like warfarin.
3. Vitamin C intake may reduce the effectiveness of medications taken together like niacin and statins for treating high blood cholesterol levels.
4. An association has been noted between vitamin C and hormonal contraceptives or alternative hormone medications leading to increased estrogen levels.
5. Vitamin C may reduce the efficacy of antiviral medications (protease inhibitors).
6. It is important to inform your doctor or pharmacist about any dietary supplements and medications you are taking, as they will advise you on any drug interactions if present.