What are Vitamins?
Vitamins are essential organic compounds required by our body to function at its best to keep us healthy. There are two general types of vitamins: water-soluble and water-insoluble.
Water soluble vitamins are regularly excreted by our body, mainly via urine. Water-insoluble vitamins, on the other hand, are stored by our body. Common storage place for most vitamins is the liver.
Vitamins which can be excreted out of the body must be replenished daily.
Vitamin A
Vitamin A is collection of water-insoluble compounds which can be stored by our body. Vitamin A is synthesized primarily from carotenoids such as beta-carotene and its function is similar to that of retinols. Collection of vitamin A compounds plays a huge role in maintaining the health of our eyes.
There are many structural forms of vitamin A, but 11-cis retinal, in particular, is the one responsible for maintaining healthy eyesight. This form of vitamin A is mainly responsible for the neural transmission of light into vision.
Benefits of Vitamin A
Apart from maintaining healthy eyesight, there are many other benefits of Vitamin A. Here is list some of those benefits:
- Smooth and healthy looking skin
- Provides resistance to colds and certain infection
- Keeps moist mucous membranes that line your urinary tract, respiratory passage and mouth
- Increases body’s immunity
- Helps safeguard against cancer
- Counters damaging effects of stress
- Aids in wound healing
- Detoxifies wound healing
- Necessary for the normal functioning of the middle ear
- Protects bowel and is very useful in treating Crohn’s disase
- Helps build healthy teeth
- Protects the lungs
Sources of Vitamin A
Carrots are the major source of vitamin A. Other sources of vitamin A include sweet potatoes, spinach, cantaloupe, kale, broccoli, winter squash, apricots, watermelon, lettuce, asparagus, peas, green beans, yellow corn, parsley and eggs.
How much of Vitamin A do you need?
Amount of vitamin you need can be determined from the Recommended Dietary Allowance (RDA) values, issued by the health and food regulation authority of the country of your residence. For United States, the RDA value for vitamin A is 900 ug per day and the upper limit is 3000 ug per day. It is important that you do not overdose, especially vitamins which can be stored in your body.