What is Vitamin A?
Vitamin A is a group of unsaturated nutritional organic compounds that are important for life. It was the first vitamin to be discovered by scientists. It includes retinal, retinoic acid, retinol as well as some ProVitamin A carotenoids. It is required for the maintenance of good vision and the immune system. This vitamin is essential for the retina of eyes in the form of retinal for both color vision and low light.
Where Does Vitamin A Come From?
Vitamin A is mainly of two different types, preformed vitamin A and ProVitamin A. The first type is actual vitamin A and is found in fish, meat, dairy products and poultry. The second type of vitamin A is obtained from colorful plant foods such as mangoes, sweet potatoes, carrots, broccoli and spinach. The most common type of ProVitamin A in dietary supplement and foods is beta carotene.
Benefits of Vitamin A
Vitamin A is a fat soluble vitamin required for maintaining healthy skin, skeletal, teeth as well as mucus membrane and soft tissue. It produces the pigments in the retina of the eye and so it is also known as retinol. It promotes good vision in low light. It may also be required for breast feeding and reproduction.
Vitamin A may also help to boost your immune system. It plays a major in the development of lymphocytes which are the cells of your immune system that combat disease and bacteria. It is very helpful for children; it can help against respiratory infections and measles. It may also help to get rid of viral infections. Patients whose immune system is depressed, vitamin A helps to boost their immune cells.
Are There Any Side Effects?
High intakes of some forms of vitamin A can be harmful, preformed vitamin A is more toxic as compared to carotenoids in high doses. Taking too much of preformed vitamin A can cause headaches, dizziness, coma and nausea. Pregnant women should not take high doses of vitamin A supplements; it can cause birth defects in the baby. The consumption of vitamin A should be less than 3000 micrograms per day.
Recommended Doses and Timing For Vitamin A
For men the daily recommended dose of preformed vitamin A is 900 micrograms whereas for women it is 800 micrograms. It should be taken with meals.
Vitamin A Supplements
Vitamin A is available in dietary supplements, it can be found as a standalone supplement but usually it comes in the form of Retinyl Palmitate or Retinyl acetate or in a combination of preformed and ProVitamin A. Many antioxidant supplements, ladies protein and multivitamins also contain this vitamin in lower doses.