Vitamin A is a yellow powder that is insoluble in water and easily soluble in organic solvents such as fats and oils, known as fat soluble substances. The digestion and absorption of vitamin A require minerals and fats. The chemical properties are relatively stable, but easily damaged by ultraviolet radiation, and should be stored in brown bottles. Vitamin A is a raw material for rhodopsin in the eyes and an essential material for skin tissue. Lack of it can lead to dry eye disease, night blindness, and other conditions. Normally, each person should consume between 4.5mg of vitamin A2 per day and should not consume too much. In recent years, research has shown that it also has anti-cancer effects. Animal liver contains a particularly high amount of vitamin A, followed by cream and eggs. Carrots, tomatoes, and other vegetables contain high levels of carotene, which is a precursor to vitamin A and is easily converted into vitamin A in the human body. Therefore, consuming vegetables can also supplement vitamin A.
Discovering History
As early as over 1000 years ago, Sun Simiao of the Tang Dynasty used animal liver as a treatment for night blindness in his book "Qian Jin Fang". In 1913, American chemist Davis and four other scientists extracted cod liver oil, which can cure dry eye disease. And a yellow viscous liquid was purified from fish liver oil, which was officially named vitamin A by British scientist Manette in 1920. Vitamin A is officially recognized internationally as a necessary nutritional factor, and deficiency can lead to night blindness.
Vitamin A can be stored in the body and does not require daily supplementation;
There are two types of vitamin A. One type is Retinol, which is the initial form of vitamin A (only present in animal food); Another type is carotene, which is converted into a precursor of vitamin A in the body (ProvitaminA, which can be consumed from both plant-based and animal based foods);
The measurement units of vitamin A are three: USP units (United States Pharmacopoea), IU units (International Units), and RF units (Retinol Equivalents);
Functional effects
1. Prevent night blindness and vision loss, which helps in the treatment of various eye diseases (vitamin A can promote the formation of photosensitive pigments in the eyes);
2. Has an anti respiratory system infection effect;
3. Helps the immune system function normally;
4. Being able to recover as soon as possible when sick;
5. Can maintain the health of the surface of tissues or organs;
6. Helps to remove age spots;
7. Promote development, strengthen bones, and maintain the health of skin, hair, teeth, and gums;
8. Topical use can help treat acne, abscesses, boils, and skin surface ulcers;
9. Helps in the treatment of emphysema and hyperthyroidism.
Recommended daily intake
For most adult males, 1000RE (or 5000 IU) is sufficient to prevent deficiency, while females require 800RE (4000 IU) during pregnancy. The latest recommended intake does not recommend an increase, but if you are a breastfeeding mother, an additional 500RE (or 2500IU) can be added in the first 6 months, and then reduced to an additional 400RE (or 2000IU) in the following 6 months.
Note: Carotenoids do not have the potential toxicity of vitamin A alcohols, and they also have anti-cancer effects, which can help reduce harmful cholesterol levels and reduce the incidence of heart disease.
Supplement cycle
Suggest supplementing daily.
Food sources rich in vitamin A
Carrots, white radishes, yellow green vegetables, yellow fruits, eggs, milk, dairy products, cream, liver, animal liver, fish liver oil, etc.
Note that the color depth of fruits and vegetables is not an absolute indicator of vitamin A content.
Additional population:
Long term malabsorption of fat, such as gastrointestinal diseases or partial gastrectomy, often leads to a lack of vitamin A.
Vitamin A is an even more important nutrient for people who wear contact lenses for a long time or have to stare at computer screens for a long time.
Pregnant and lactating women also need vitamin A.
Deficiency syndrome:
Long term severe deficiency of vitamin A can lead to dry eye syndrome, night blindness, and even blindness.
Long term malabsorption of fat often leads to a lack of vitamin A, which often occurs in children under 5 years old, mainly due to insufficient dietary intake.
Excessive performance:
Symptoms such as abnormal allergies, fever, diarrhea, and dizziness may manifest after 6 hours of overdose.
Nutrition expert tips:
1. When consuming 400 IU or more of vitamin E per day, a minimum of 1000 IU of vitamin A should also be consumed;
2. When taking oral contraceptives, it is necessary to reduce the amount of vitamin A used;
3. During a week, when three meals contain a large amount of animal liver, carrots, spinach, sweet potatoes, and cantaloupe, there is no need to supplement with vitamin A;
4. Vitamin A and mineral oil should not be taken together;
5. When used in combination with vitamin B, vitamin D, E, calcium, phosphorus, and zinc, vitamin A can fully exert its effects. (Zinc is necessary to release vitamin A stored in the liver);
6. Vitamin A can also prevent oxidation of vitamin C.
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