What is Vitamin A?
Vitamin A is a fat-soluble vitamin that is important in maintaining human health. It is found in various foods, including animal and plant foods. Vitamin A has many forms, including retinol, retinyl esters, and β-carotene.
What is Vitamin C?
Vitamin C, or ascorbic acid, is a water-soluble vitamin essential for human health. Vitamin C is an antioxidant that has many physiological functions. Since the human body cannot synthesize vitamin C alone, it must be obtained through diet or supplementation.
Source
Vitamin A:
Animal foods:
Liver: Animal liver is a good source of vitamin A, especially beef liver and chicken liver. The liver is rich in retinol and retinyl esters.
Egg yolk: Egg yolk also contains a certain amount of vitamin A, mainly in the form of retinol esters.
Cod liver oil: Cod liver oil is a good source of vitamin A and vitamin D, especially cod liver oil from sharks, whales, and deep-sea fish.
Plant foods:
Carrots: Carrots are rich in beta-carotene, a plant-derived provitamin A. In the body, beta-carotene can be converted into active retinol.
Spinach: Spinach is a green leafy vegetable rich in beta-carotene and other carotenoids and is one of the good sources of vitamin A.
Pumpkin: Pumpkin is rich in beta-carotene and a nutritious vitamin A source.
Sweet peppers: Red, yellow, and orange bell peppers contain high amounts of beta-carotene and are a good source of plant-based vitamin A.
Vitamin C:
Citrus fruits: Citrus fruits are rich sources of vitamin C, including oranges, lemons, pomelo, grapefruit, limes, etc. These fruits contain a lot of vitamin C and are rich in other nutrients.
Strawberry: Strawberry is a fruit with a very high vitamin C content. Every 100 grams of strawberry contains about 59 mg of vitamin C, one of the high-quality sources of vitamin C.
Tomato: Tomato is rich in vitamin C, with about 23 mg per 100 grams of tomato. Raw or cooked tomatoes can provide vitamin C.
Green leafy vegetables: Green leafy vegetables also contain a certain amount of vitamin C, such as spinach, broccoli, cabbage, kale, lettuce, etc. In addition to being rich in vitamin C, these vegetables also provide other important nutrients.
Red pepper: Red pepper is a vegetable with a very high vitamin C content. Every 100 grams of red pepper contains about 127 mg of vitamin C, a very high-quality vitamin C source.
Tropical fruits: Tropical fruits are also rich in vitamin C, such as mango, papaya, pineapple, lychee, etc.
Other vegetables and fruits: Some other vegetables and fruits, such as tomatoes, mangoes, kiwis, oranges, cherries, etc., also contain a certain amount of vitamin C.
Effect
Vitamin A:
Maintain visual health: Vitamin A is one of the components of the visual pigment in the retina and is essential for maintaining visual health and normal visual function. It helps keep the typical structure of the retina and is involved in the activity of photoreceptors during visual conduction.
Promote growth and development: Vitamin A plays a vital role in cell differentiation, growth, and development. Vitamin A is necessary for maintaining average growth and development during infancy and childhood. Vitamin A deficiency may lead to problems such as growth retardation and skeletal deformities.
Maintain skin and mucous membrane health: Vitamin A helps maintain the typical structure and function of the skin and mucous membranes. It promotes the renewal and repair of epidermal cells, helping to prevent problems such as dry skin, roughness, ulcers, and infections.
Support the immune system: Vitamin A is also very important for the normal functioning of the immune system. It helps to enhance the body's resistance to infection, promotes the proliferation and activity of immune cells, and helps reduce the occurrence of infections and diseases.
Maintain reproductive health: Vitamin A is also essential for the health of the reproductive system in men and women. It is involved in regulating the development and function of germ cells, helping to maintain normal reproductive hormone levels and the normal function of the reproductive system.
Vitamin C:
Antioxidant effect: Vitamin C is a powerful antioxidant that helps remove free radicals and other harmful substances, reduce oxidative stress damage to cells, and protect cells from oxidative damage.
Promote collagen synthesis: Vitamin C is a critical component in collagen synthesis, which helps maintain the health of skin, bones, blood vessels, and other connective tissues and promotes wound healing and skin repair.
Enhance immune function: Vitamin C regulates immune cells' function, including the activity of white blood cells and the production of antibodies, which helps to improve the body's resistance to infection and reduce the occurrence of colds and other respiratory diseases.
Promote iron absorption: Vitamin C can promote the absorption of non-heme iron, help improve iron utilization, and prevent iron deficiency anemia.
Anti-inflammatory effect: Vitamin C has a specific anti-inflammatory effect, which helps to reduce inflammatory reactions and relieve pain.
Maintain the health of the nervous system: Vitamin C synthesizes neurotransmitters such as dopamine, norepinephrine, and adrenaline, which helps maintain the normal function of the nervous system.
Promotes antioxidant regeneration: Vitamin C can also help regenerate other antioxidants, such as vitamin E, enhancing their effects within cells.
Reduces the risk of cardiovascular disease: The antioxidant effect of vitamin C helps lower blood cholesterol levels and prevent the occurrence of cardiovascular diseases such as atherosclerosis.
Side Effect
Vitamin A:
Dizziness and headache: Excessive intake of vitamin A may cause uncomfortable symptoms such as dizziness and headache.
Nausea and vomiting: Long-term excessive intake of vitamin A may cause nausea, vomiting, and stomach discomfort.
Skin problems: Long-term excessive intake of vitamin A may cause skin problems such as dry skin, peeling, itching, rash, etc.
Liver damage: Long-term high-dose vitamin A intake may negatively impact the liver, leading to abnormal liver function or liver damage.
Bone problems: Long-term excessive intake of vitamin A may cause bone problems such as bone deformity, osteoporosis, etc.
Hair loss: Long-term excessive intake of vitamin A may cause hair loss or hair thinning.
Nervous system problems: Long-term excessive intake of vitamin A may cause nervous system problems such as dizziness, insomnia, fatigue, and other symptoms.
Child development problems: Excessive intake of vitamin A by pregnant women may affect fetal development and cause congenital disabilities in babies. For children, excessive intake of vitamin A may also affect growth and development.
Vitamin C:
Digestive discomfort: Excessive vitamin C intake may cause digestive discomfort, including diarrhea, nausea, vomiting, heartburn, and abdominal pain. This usually occurs when excessive vitamin C is consumed, especially when large doses are consumed in a short period of time.
Gastrointestinal problems: Excessive vitamin C intake may cause gastrointestinal issues, such as flatulence, bloating, abdominal pain, and indigestion.
Uric acid stones: Vitamin C can promote the excretion of uric acid. Excessive vitamin C intake may increase uric acid concentration in urine and increase the risk of uric acid stones.
Iron absorption problems: High doses of vitamin C may affect the absorption of non-heme iron, which may lead to insufficient iron absorption in some people.
Drug interactions: High doses of vitamin C may interact with certain drugs, affecting their absorption, metabolism, and excretion, thereby affecting their efficacy.
Allergic reactions: Although rare, some people may be allergic to vitamin C and experience allergic reactions, such as rash, itching, urticaria, and difficulty breathing.
Iron toxicity: Excessive vitamin C may increase iron toxicity for people with iron overload (such as patients with hemoglobinopathy).
