Index
These compounds are converted to an active form in your body. For example, beta-carotene is converted to retinol in the small intestine.
What is vitamin A and what are some of its benefits?
Vitamin A is the generic term for a group of fat-soluble compounds essential to human health.
They are essential for many processes in your body, including maintaining healthy vision, ensuring the normal function of your immune system and organs, and helping the proper growth and development of babies in the womb.
It is recommended that men receive 900 mcg, women 700 mcg, and children and adolescents 300-600 mcg of vitamin A per day.
Vitamin A compounds are found in animal and plant foods and come in two different forms: preformed vitamin A and provitamin A.
Preformed vitamin A is the active form of the vitamin, which your body can use as-is. It is found in animal products such as meat, chicken, fish, and dairy products and includes compounds such as:
- Retinol.
- Retinal.
- Retinoic acid.
Provitamin A carotenoids (alpha-carotene, beta-carotene, and beta-cryptoxanthin) are the inactive form of the vitamin found in plants.
Six essential health benefits of vitamin A
- Protect your eyes from night blindness and age-related decline
Vitamin A is essential to preserve your eyesight.
The vitamin is necessary to convert the light that reaches your eye into an electrical signal that can be sent to your brain.
One of the first symptoms of vitamin A deficiency can be night blindness, known as nyctalopia.
Night blindness occurs in people with vitamin A deficiency since the vitamin is a central component of the pigment rhodopsin.
Rhodopsin is found in the eye’s retina and is extremely sensitive to light.
People with this condition can still usually see during the day but have reduced vision in the dark as their eyes struggle to capture light at lower levels.
In addition to preventing night blindness, eating adequate amounts of beta-carotene can help decrease the decrease in vision that some people experience as they age.
Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. Although its exact cause is unknown, it is believed to result from cellular damage to the retina attributable to oxidative stress.
The Age-Related Eye Disease Study found that giving people over 50 with some visual degeneration an antioxidant supplement (including beta-carotene) reduced their risk of developing advanced macular degeneration by 25%.
However, a recent Cochrane review found that beta-carotene supplements alone will not prevent or delay the decrease in vision caused by AMD.
Summary
Eating adequate amounts of vitamin A prevents the development of night blindness and can help decrease age-related decrease in vision.
- May decrease the risk of certain cancers.
Cancer occurs when abnormal cells begin to grow or divide uncontrollably.
As vitamin A plays a vital role in the growth and development of your cells, its influence on cancer risk and its role in cancer prevention is of interest to scientists.
In observational studies, ingesting higher amounts of vitamin A in the form of beta-carotene has been linked to a lower risk of certain types of cancer, including Hodgkin lymphoma and cervical, lung, and bladder cancer.
However, although a high intake of vitamin A from plant foods has been associated with a lower risk of cancer, foods of animal origin that contain active forms of vitamin A are not linked in the same way.
Similarly, vitamin A supplements have not shown the same beneficial effects.
In fact, in some studies, smokers who took beta-carotene supplements experienced an increased risk of lung cancer.
The relationship between vitamin A levels in your body and cancer risk is not yet fully understood.
Still, current evidence suggests that getting adequate vitamin A, especially from plants, is essential for healthy cell division and may reduce the risk of some types of cancer.
Summary
Adequate intake of vitamin A from whole plant foods can reduce the risk of certain cancers, including Hodgkin lymphoma and cervical, lung, and bladder cancer. However, the relationship between vitamin A and cancer is not fully understood.
- It supports a healthy immune system.
Vitamin A plays a vital role in maintaining your body’s natural defenses.
This includes mucous barriers in the eyes, lungs, intestines, and genitals that help trap bacteria and other infectious agents.
It is also involved in the production and function of white blood cells, which help capture and eliminate bacteria and other pathogens from the bloodstream.
This means that a deficiency in vitamin A can increase your susceptibility to infection and delay your recovery when you get sick.
In fact, in countries where infections such as measles and malaria are common, correcting vitamin A deficiency in children has lowered the risk of dying from these diseases.
Summary
Having enough vitamin A in your diet helps keep your immune system healthy and functioning at its best.
- Reduces the risk of Acne
Acne is a chronic, inflammatory skin disorder.
People with this condition develop sore spots and blackheads, often on the face, back, and chest.
When the oil glands become clogged with dead skin and oils, these spots occur. These glands are located in the hair follicles of the skin and produce sebum, an oily and waxy substance that keeps the skin lubricated and waterproof.
Although blemishes are physically harmless, Acne can have a severe effect on people’s mental health, leading to low self-esteem, anxiety, and depression.
The exact role that vitamin A plays in the development and treatment of Acne remains unclear.
It has been suggested that vitamin A deficiency may increase the risk of developing Acne, as it causes an overproduction of the protein keratin in the hair follicles.
This would increase the risk of Acne by making it difficult to remove dead cells from the hair follicles, leading to blockages.
Some vitamin A-based acne medications are now available with a prescription.
Isotretinoin is an example of an oral retinoid that effectively treats severe Acne. However, this drug can have serious side effects and should only be taken under medical supervision.
Summary
The exact role of vitamin A in the prevention and treatment of Acne is unclear. However, vitamin A-based medications are often used to treat severe Acne.
- Supports bone health
The primary nutrients needed to keep bones healthy with age are protein, calcium, and vitamin D.
However, eating enough vitamin A is also necessary for proper bone growth and development, and a deficiency in this vitamin has been linked to poor bone health.
People with lower levels of vitamin A in their blood are at a higher risk of bone fractures than people with healthy levels.
Additionally, a recent meta-analysis of observational studies found that people with the highest amounts of vitamin A in their diet had a 6% lower risk of fractures.
However, low levels of vitamin A may not be the only problem for bone health. Some studies have found that people with high intakes of vitamin A are also at increased risk of fractures.
Still, these findings are based on observational studies that cannot determine cause and effect.
This means that the link between vitamin A and bone health is currently not fully understood, and more controlled trials are needed to confirm what has been seen in observational studies.
Keep in mind that vitamin A status alone does not determine your risk for fractures, and the impact of the availability of other vital nutrients, such as vitamin D, also plays a role.
Summary
Eating the recommended amount of vitamin A can help protect bones and reduce the risk of fractures, although the connection between this vitamin and bone health is not fully understood.
- Promotes healthy growth and reproduction
Vitamin A is essential to maintain a healthy reproductive system in both men and women, as well as to ensure the average growth and development of embryos during pregnancy.
Studies in rats examining the importance of vitamin A in male reproduction have shown that a deficiency blocks sperm cell development, causing infertility.
Similarly, animal studies have suggested that vitamin A deficiency in women can affect reproduction by reducing egg quality and affecting the implantation of eggs in the uterus.
In pregnant women, vitamin A is also involved in the growth and development of many vital organs and structures of the fetus, including the skeleton, nervous system, heart, kidneys, eyes, lungs, and pancreas.
However, although it is much less common than vitamin A deficiency, too much vitamin A during pregnancy can harm the growing baby and lead to congenital disabilities.
Therefore, many health authorities recommend that women avoid foods that contain concentrated amounts of vitamin A, such as pate and liver, and supplements that contain vitamin A during pregnancy.
Summary
Adequate amounts of vitamin A in the diet are essential for babies’ reproductive health and healthy development during pregnancy.
Taking too much vitamin A can be risky.
Vitamin A is a fat-soluble vitamin that is stored in your body. This means that excessive consumption can lead to toxic levels.
Hypervitaminosis A is caused by consuming too much-preformed vitamin A through your diet or supplements that contain the vitamin.
Symptoms can include
- Sickness.
- Dizziness
- Headaches.
- Pain.
- Death.
Although it can be caused by excessive intake from the diet, this is rare compared to excessive consumption of supplements and medications.
Also, eating a lot of provitamin A in its plant form does not carry the same risks since its conversion to the active format in your body is regulated.
Summary
Eating high amounts of the active form of vitamin A from animal foods, medications, or supplements can be toxic. Consuming too much provitamin A from plant foods is unlikely.
The bottom line
Vitamin A is vital to many vital processes in your body.
It is used to maintain healthy vision, ensure the normal function of organs and the immune system, and establish babies’ average growth and development in the womb.
Too little and too much vitamin A could have adverse effects on your health.
