Vitamin A provides several health benefits, including growth, cell recognition, vision, and the normal functioning of your immune system.
Vitamin A is found in two unique forms, such as preformed vitamin A and provitamin A.
Preformed vitamin A is a fat-soluble vitamin that the body only get it from foods such as animal products, including meat, chicken, fish, and dairy, and includes retinol, retinal, and retinoic acid compounds (1).
Provitamin A is the inactive form that can be found in plant’s carotenoids, alpha-carotene, beta-carotene, and beta-cryptoxanthin. When you eat these plants, your body transforms the inactive form into your body’s active form.
For instance, in your small intestine, beta-carotene is converted to retinol, which is an active form of vitamin A (2).
Here are 6 health benefits of vitamin A and its functions.
Table of Contents
1. Protects Your Eyes
Vitamin A is essential for your vision. You need the vitamin to transform the light that hits your eye into an electrical signal that can be sent to your brain. Night blindness, known as nyctalopia, may be one of the first signs of vitamin A deficiency (3).
Night blindness occurs in people with a deficiency of vitamin A as the vitamin is a major component of rhodopsin pigment. Rhodopsin is found in your eye’s retina and it is light sensitive.
People with this condition can still see normally throughout the day, but in the darkness, their vision is reduced as their eyes struggle to gain light at lower levels. Besides these benefits of vitamin A, eating enough beta-carotene can help slow down the decline (4).
The leading cause of blindness is age-related macular degeneration (AMD). Although its exact cause is unknown, it is believed to be related to oxidative stress because of cellular damage to the retina (5).
An age-related eye blindness study found that giving an antioxidant supplement, including beta-carotene, to people over 50 with AMD reduced their risk of developing advanced macular degeneration by 25 percent (6).
A recent review, however, found that beta-carotene supplements alone will not stop AMD’s decline in vision (7).
2. Reduces Chronic Skin Disorder
People with acne, most often on the neck, back, and chest, develop red spots and blackheads. Such spots occur when dead skin and oils block the sebaceous glands.
These glands are in your skin’s hair follicles and contain sebum. It is a waxy substance that keeps your skin waterproof and lubricated.
Although the spots are physically harmless, Acne can have a severe effect on the mental health of people, leading to anxiety and depression (8).
However, the exact role of vitamin A in the treatment of acne remains unclear (9).
Vitamin A deficiency can increase your risk of developing acne as it causes your hair follicles to overproduce the protein keratin (10).
This would increase your risk of acne by making it harder to remove dead skin cells from hair follicles, which contributes to blockages.
Isotretinoin is one example of an effective oral retinoid in the treatment of severe acne. This drug may have serious side effects, however, and must be taken under medical supervision only (11, 12).
3. Enhances Immune System
Vitamin A plays an important role in preserving the natural defenses of your body. It involves the mucous membranes that help trap bacteria and other infectious agents in your skin, lungs, intestines, and genitals.
It also involves the production and function of white blood cells that help capture and clear bacteria from your bloodstream.
This means that if you become ill, a vitamin A deficiency can increase your susceptibility to infection (13).
In fact, the correction of vitamin A deficiency in children has been shown to decrease the risk of dying from these diseases in countries where infections such as measles and malaria are common (14).
4. Reduces Risk of Cancer
Cancer occurs when uncontrolled growth or division of abnormal cells starts. Since vitamin A plays a major role in the development of your cells, scientists are interested in its role in cancer prevention (15, 16).
Consumption of beta-carotene can help reduce the risk of certain types of cancer. In these studies, cancers such as Hodgkin’s lymphoma, cervical, lung, and prostate cancer were studied (17, 18, 19, 20).
Although large intakes of vitamin A from plant foods have been connected to a lower risk of cancer, animal foods containing active forms of vitamin A have not been linked in the same way (21, 22).
Vitamin A supplements do not have the same benefits. In fact, smokers taking beta-carotene supplements had an increased risk of lung cancer in some studies (23, 24, 25, 26).
The link between the body’s levels of vitamin A and the risk of cancer is not clear. However, existing evidence shows that getting adequate vitamin A, especially from plants, is important for healthy cell division and may reduce the risk of certain cancers (27).
5. Promotes Healthy Growth
Vitamin A is essential to maintaining a healthy male and female reproductive system. It ensures the normal growth and development of embryos during pregnancy. Rat studies investigating the role of vitamin A in the male reproductive system.
The study shows that vitamin A deficiency can impair sperm cell formation, which is the major cause of infertility (28, 29).
Similarly, animal studies have suggested that female vitamin A deficiency can affect reproduction by reducing the quality of eggs and affecting the womb implantation of eggs (30).
Vitamin A is also involved in the growth and development of many of the unborn child’s major organs and tissues, including the skin, nervous system, heart, kidneys, ears, lungs, and pancreas, in pregnant women.
However, too much vitamin A can also be harmful to the growing baby during pregnancy and can cause birth defects (31, 32).
Most health experts also pointed out that women avoid foods containing enormous amounts of vitamin A, such as liver and vitamin A supplement during pregnancy.
6. Vitamin A Supports Bone Health
Protein, calcium, and vitamin D are the primary nutrients for maintaining healthy bones. Eating enough vitamin A, however, is also necessary for proper bone growth and development.
However, poor bone health has also been associated with VA deficiency. In fact, people with lower vitamin A are at higher risk of bone fractures than those with healthy levels (33).
In addition, a recent meta-analysis of observational studies showed that people with the highest average dietary amounts of vitamin A had a 6 percent reduced risk of bone fractures (34).
However, for bone health, low levels of vitamin A may not be the only problem. Some studies have found that there is also a higher risk of fractures in people with high vitamin A intake (35).
These findings are based on observational studies unable to determine cause and effect.
This means that the link between vitamin A and bone health is not clear at the moment, and we need more controlled studies to confirm it.
Keep in mind that vitamin A alone does not determine your risk of bone fractures. Other nutrients, such as vitamin D, also play an important role (36).
Conclusion
Vitamin A has many benefits, such as maintaining healthy vision, ensuring the normal functioning of your organs and immune system, and promoting the normal growth and development of the baby in the womb.
Either too little or too much vitamin A may have negative health effects.
The best way to ensure that you get the right balance is to eat foods rich in vitamin A as part of your normal diet and avoid excessive levels of supplementation.