Vitamin A is the name for a fat-soluble retinoid, which is stable to heat, acid, and alkali and is easily oxidized. There are two types of vitamin A, one is vitamin A alcohol, which only exists in animal foods and is the original form of vitamin A; the other is carotene, which can be ingested from plant foods or animal foods and converted into vitamin A in the body. The content of flavonols varies from person to person. Vitamin A contains a photosensitive substance (ie, rhodopsin) that helps make the retina, which is very important for night vision; promotes human growth and development; and maintains normal skin and mucous membranes for the normal functioning of the immune system.
Common uses of vitamin A
Vitamin A is one of the vitamins that the human body needs and can be obtained through the diet.
Vitamin A Health Benefits
Important physiological functions of vitamin A include:
1. Helps maintain good vision
Vitamin A maintains normal visual responses and helps prevent some eye diseases such as dry eye, night blindness, conjunctivitis, vision loss, and age-related macular degeneration.
2. Promote growth and development
Retinol promotes the production of glycoproteins, promotes development, makes bones stronger, and maintains healthy teeth, gums, skin, and hair.
3. Helps maintain normal immunity
In particular, the body's resistance to respiratory infections and parasitic infections is helpful for the treatment of hyperthyroidism and emphysema.
4. It can maintain the integrity and soundness of the epithelial structure
Prevent dry skin and mucous membranes from keratinization, and external use helps to treat acne, pustules, skin surface ulcers, etc.
vitamin A deficiency
If there is a vitamin A deficiency, it may be caused by insufficient vitamin A intake, malabsorption of fat, or liver disease. Lack of vitamin A can lead to poor development, impaired immune function and hematopoietic function, keratinization of epidermal tissue, dry eye disease, night blindness and even corneal softening, perforation and blindness. Specific symptomatic treatment is required.
Excessive intake of vitamin A
Vitamin A should not be taken in excess. A single large dose of vitamin A (more than 200,000 mg) may cause blurred vision, nausea, vomiting, and dizziness; long-term daily intake of more than 10,000 micrograms of oral vitamin A will cause headache, nausea, and skin irritation. , diarrhea, joint and bone pain, birth defects, bone thinning and liver damage.
Vitamin A and Common Medications
1. Orlistat can reduce the absorption of vitamin A, other fat-soluble vitamins and β-carotene, and reduce the plasma concentration.
2. Taking vitamin A and vitamin A together will cause excessive intake of vitamin A and cause side effects.
3. Taking anticoagulants together with vitamin A will increase the risk of bleeding.
4. Taking bexarotene with vitamin A supplements increases the chance of side effects, such as itchy, dry skin.
5. Concomitant use of hepatotoxic drugs with high doses of vitamin A may increase the risk of liver disease.
Food sources of vitamin A
Vitamin A is mainly found in animal liver, fatty fish, egg yolk, and vegetables containing carotene.
Vitamin-A Rich Foods
- pork liver
Recommended Vitamin A Health Products
- Sunshine – Advance 50+ Multivitamins & Minerals 100 Capsules
- Webberjian – Women's Total Multivitamin 90 Vegetarian Capsules
- Jamieson – Children's Multivitamin 60 Chewable Tablets