What is Vitamin A? What are its benefits?
What is Vitamin A?
Vitamin A is a type of fat-soluble vitamin stored in the liver. There are two types of vitamin A found in foods. The first type is preformed vitamin A, also known as retinol, which is an active form of vitamin A. It is found in animal-based foods such as meat, fish, poultry, full-fat dairy, and dairy products.
The second type of vitamin A is known as provitamin A and is found in plant-based foods like fruits and vegetables. Another name for this type is carotenoids, which give foods their dark color, i.e., pigments. This type can be converted into the active form of vitamin A. There are over 500 known carotenoids.
The most common type of provitamin A is beta-carotene. Vitamins are essential nutrients that are either not produced by the body at all or are produced in insufficient amounts to prevent negative health outcomes or diseases. Therefore, it is necessary to provide the body with vitamins through proper nutrition and only when medically necessary through vitamin supplements. Vitamin A is also available in the form of capsules and dietary supplements. It is often added to supplements in the form of retinyl acetate or retinyl palmitate (preformed vitamin A), beta-carotene (provitamin A), or a combination of both.
What are the Benefits of Vitamin A?
- Vitamin A contributes to the healthy formation and maintenance of teeth, bones, soft tissue, mucous membranes, and skin structures. It produces pigments that provide color to the eye retina.
- Vitamin A especially facilitates good vision in low light conditions. It also plays a significant role in healthy pregnancy and breastfeeding with breast milk after pregnancy.
- Beta-carotene type vitamin A is an antioxidant. Antioxidants protect cells from damage caused by substances called free radicals.
- It is known that free radicals contribute to some chronic and long-term diseases and play a role in aging. Consuming food sources containing beta-carotene may reduce the risk of cancer. However, it has been observed that beta-carotene supplements containing do not reduce the risk of cancer.
What is Anxiety? What are the Diagnosis and Treatment Methods?
Vitamin A Deficiency
Inadequate levels of vitamin A in the body can lead to various eye and vision problems. These problems include reversible night blindness and irreversible corneal damage called xerophthalmia. Vitamin A deficiency can also lead to hyperkeratosis or dry, scaly skin.
Excess of Vitamin A
Excessive intake of vitamin A can also cause illness. High doses of vitamin A can lead to birth defects. Acute vitamin A poisoning typically occurs when an individual consumes several hundred thousand IU, i.e., international units of vitamin A. Chronic vitamin A poisoning can occur in adults who regularly consume more than 25,000 IU per day.
Babies and children are more sensitive to vitamin A. They can also become ill after taking products containing vitamin A or retinol in smaller doses.
Consuming large amounts of beta-carotene usually does not make individuals ill. However, high doses of beta-carotene can turn the skin color yellow or orange. When beta-carotene consumption decreases, the skin color returns to normal.
Foods Containing Vitamin A
Since there are 2 types of vitamin A, sources of vitamin A can be divided into 2 categories.
- Preformed vitamin A is obtained from animal foods such as trout, cottage cheese, liver, king mackerel, cod liver oil, salmon, chicken liver, butter, egg yolk, whole milk, cheese, cream, kidney, herring, and fish oil.
- Provitamin A, on the other hand, is abundant in yellow fruits and dark green leafy vegetables such as pumpkin, broccoli, carrots, spinach, kale, dandelion greens, red bell pepper, cabbage, parsley, Swiss chard, Brussels sprouts, sweet potatoes, and oranges.
The darker the color of the vegetable or fruit, the more beta-carotene it contains. Plant-based beta-carotene sources do not contain fat and cholesterol. Consuming these sources with fat increases the absorption of vitamin A derived from them. The best way to obtain the daily requirement for vitamin A, as well as other essential vitamins, is to consume a wide variety of fruits, vegetables, fortified dairy products, legumes such as beans, lentils, and whole grains.
