[Biology Class Notes] on Vitamin A Pdf for Exam

Popularly called Retinol, Vitamin A is fat-soluble alcohol and is widely found in fatty fish-liver oils. Vitamin A is also found in milk fat, eggs, and other such healthy items. You won’t find Vitamin A in plants, but you will find it in vegetables and fruits. So is why doctors highly recommend consuming fruits and vegetables on the regular basis. After consumption of fruits and vegetables, vitamin A gets destroyed upon exposure to heat, light, or air. Vitamin A, functioning directly in vision, gets converted into retinaldehyde, which is an essential part and is present in the retina of the eye. Vitamin A, in the form of retinoic acid, is combined with specific proteins, and functions in the regulation of embryonic development and growth. This acid is also vital for the maintenance of the epithelial tissues for sperm formation and functioning of the immune system.

In general, we humans require Vitamin A in a small amount. The recommended intake on the regular basis is 1000 and 800 micrograms. Most of the Vitamin A gets stored in the liver area in the form of retinal esters. These esters then break into all-trans-retinol and enter into your bloodstream, so that our body can use it for functioning.

What are the Functions of Vitamin A in Your Body?

Like other nutrients, vitamin A is essential for our body for cell growth and immune function. One of the essential roles of vitamin A is for healthy eyes. So is why carrot vitamin A is higher recommended. Daily consumption of carrots can help in building proper eye-sight. Further, it also helps in protecting and maintaining the cornea – the outermost layer of the eye. Additionally, another major use of Vitamin A is to help maintain the surface tissues such as skin, intestines, and lungs.

Sources and Types of Vitamin A

There are two types of vitamin A. One is retinol, which is found in animal products and sources are milk, eggs, cheese, and cream. Pro-vitamin A is another major type and sources are plant-based foods like vegetables and fruits. Apple for Vitamin A is highly recommended. Other sources with high-intake of vitamin A are-

Benefits of Vitamin A

As mentioned above, there are different benefits of Vitamin A. Some of the health benefits from vitamin A are-

1. Carries Antioxidant: 

Pro-vitamin A like alpha-carotene and beta-carotene are highly essential. These carotenoids help in fighting free radicals and help in bringing down stress. Oxidative stress which is quite common among people can result in illness and diabetes.

2. Highly Essential For Eye Health: 

As mentioned above, vitamin A is very essential for better eye-sight. Adequate intake of vitamin A will help in protecting against eye disease. According to studies, it helps in diseases like age-related macular degeneration (AMD). Higher blood levels of beta-carotene, alpha-carotene, and beta-cryptoxanthin reduce the risk of AMD in aged people. To get vitamin A for eyes, it is important to consume the right source of food. 

3. Mostly Protects From Cancers

Since vitamin A carries antioxidant properties, it helps bring down the cancer issue. There has been a study on over 10,000 adult smokers carrying the highest blood levels of alpha-carotene and beta-cryptoxanthin. Smokers who consumed food with vitamin A carry a 61% low risk of dying.

4. Skin Care

Vitamin A is widely known for repairing skin. This is due to the Rentin-A, which is the brand name for tretonis and works by signaling to the cells to grow at a faster rate.

Other than these, the use of vitamin A is also for the formation of teeth, soft tissues, and white blood cells.

Vitamin A Deficiency

Deficiency in Vitamin A can lead to different health disorders. The common effect is on the eye and the epithelial tissues. One of the earliest signs of vitamin A deficiency is night blindness. Many people face this night blindness issues that can increase over a period of time.

In children, extreme deficiency of Vitamin A can lead to malnourishment of children, and the condition is known as Xerophthalmia. In this condition, the eyes of the patient get sensitive to light and eyelids turn swollen. There are early signs of vitamin A deficiency that can be reflected in the changes in mucous membranes of the mouth, throat, and respiratory.

The intake of Vitamin A is quite tricky. Less intake can lead to disease and too much can also create health issues. It is highly important to have the right intake of vitamin A source foods. The best is to seek doctor consultation to check what and how much source is essential for the intake of vitamin A.