Do you know that Vitamin A is an important fat-soluble nutrient that plays an important role in your body?
They are important for different processes in your body.
These include maintaining healthy vision, ensuring normal function of immune system and organs, and aiding the proper growth and development of babies in the womb.
Moreover, according to recommendations, men can get 900 mcg, and women should get 700 mcg.
While children and adolescents need 300 to 600 mcg of vitamin A per day.
Moreover, vitamin A is found in both animal and plant foods.
And it comes in two forms: preformed vitamin A and provitamin A.
Thus, it exists naturally and in the form of supplements that you can consume.
Keep on reading to learn more about vitamin A, its benefits, food sources, and deficiency as well as toxicity in this guide.
Vitamin A is a singular nutrient and is the name for fat-soluble compounds including regional, retinal, and retinyl esters.
Moreover, there are 2 types of vitamin A that are present in food sources.
Preformed vitamin A i,e, retinol, and retinyl esters occur exclusively in animal products.
These include dairy, liver, and fish.
While Provitamin A carotenoids are present in plants foods like fruits, vegetables, and oil are in abundance.
In order to use them, your body must convert both forms of vitamin A to retinal and retinoic acid.
These are active forms of the vitamin.
As vitamin A is fat-soluble, your body has the ability to store them in tissues for later use.
Your body will keep most of the vitamin A in your liver in the form of retinyl esters.
Then will then be broken down into all-trans-retinol which binds to retinol-binding protein, i.e. RBS.
From there it enters your bloodstream, at which point your body can use it.
Functions of Vitamin A in your Body
Vitamin A is important for your overall health, supporting cell growth, immune function, fetal development, and vision.
Perhaps, one of the best functions of vitamin A is its role in vision and eye health.
Retinal, which is the active form of vitamin A, combines with the protein opsin to form rhodopsin.
It is a molecule that is important for color vision and low-light vision, according to studies.
Moreover, it also helps to protect and maintain the cornea, which is the outermost layer of your eye.
And the Conjunctive is a thin membrane that covers the surface of your eye and inside of your eyelids.
Furthermore, vitamin A also helps to maintain surface tissues.
These include your skin, intestines, lungs, bladder, and inner ear.
It also helps to support immune function by supporting the growth and distribution of T-cells of white blood cells.
These cells protect your body from infection, according to studies.
Additionally, it also supports healthy skin cells, male and female reproduction, and fetal development.
Let’s discuss these health benefits in detail.
1# Prtoects your Eyes from Night Blindness and Age-Related Decline
One of the important things to note is that vitamin A helps to prevent your eyesight.
Your body needs this vitamin to convert the light that hits your eye into an electrical signal.
This signal is then sent to your brain.
According to studies, one of the symptoms of vitamin A deficiency can be nighttime blindness i,e, Nyctalopia.
Rhodopsin is present in the retina of your eye and is also extremely sensitive to light.
If you have this condition, you can still see normally during the day.
However, you will experience a reduction in vision in darkness as your eyes struggle to pick up light at lower levels.
Additionally, other than preventing night blindness, eating enough amount of beta-carotene can also help to slow the decline in eyesight that you might experience with age.
Age-related macular degeneration, AMD is the leading cause of blindness in developed countries.
Although the exact cause of it is unknown.
Man doctors believe that it can be the result of cellular damage to the retina, which is attributed to oxidative stress.
According to the Age-Related Eye Disease Study, when people over the age of 50 with some eyesight degeneration consume an antioxidant supplement, with beta-carotene, shows a reduction in the risk of developing advanced macular degeneration by 25%.
However, a recent review suggests that eta0carotence supplements alone cannot prevent or delay the decline in eyesight due to AMD.
2# Can Help to Lower the Risk of Certain Cancers
Cancer occurs when abnormal cells begin to grow or divide in an uncontrolled way.
As vitamin A plays an important role in the growth and development of cells, its influence on cancer risk.
And its role in cancer prevention is of interest to scientists.
According to observational studies, eating a higher amount of vitamin A in the form of beta-carotene can help to decrease the risk of certain types of cancers.
These include Hodgkin’s lymphoma, as well as cervical, lung, and bladder cancer.
Though, doctors often associate high intakes of vitamin A from plant foods to reduce the risk of cancers.
Animal food sources which contain active forms of vitamin A are not linked in the same way.
In the same way, vitamin A supplements may not have the same beneficial effects.
Some studies indicate that smokers taking beta-carotene supplements can experience an increase in the risk of lung cancer.
Moreover, the relationship between vitamin A levels in your body and cancer risk is not fully understood.
Current evidence, however, suggests that getting enough vitamins from plants can help.
It is important for healthy cell division and may also help to reduce the risk of some types of cancer.
3# Healthy Immune System
Vitamin A plays an important role in maintaining the natural defenses of your body.
This includes mucous barriers in your eyes, lungs, guts, and genitals as they can trap bacteria and other infectious agents.
Moreover, it also helps in the production and function of white blood cells,
This helps to capture and clear bacteria and other pathogens in your bloodstream.
Vitamin A deficiency, however, can increase your susceptibility to infections and even delay your recovery when you get sick.
In countries where infections like measles and malaria are common, correcting vitamin A deficiency in children can help.
Furthermore, it also helps to decrease the risk of dying from these diseases, according to studies.
Therefore, having enough vitamin A can help to keep your immune system healthy and functioning at its best.
4# Reduce your Risk of Acne
Acne is a chronic and inflammatory skin disorder.
People with this condition often develop painful spots and blackheads, often on their face, back, and chest.
Moreover, these spots appear when the sebaceous glands get clogged up with dead skin and oils.
These glands are present in hair follicles on your skin and produce sebum.
This is an oily, waxy substance that keeps your skin lubricated and waterproof.
Though these spots are physically harmless, acne can have a serious effect on your mental health and can also lead to low self-esteem, anxiety, and depression.
The role of vitamin A in the development and treatment of acne, however, is unclear.
Still, doctors suggest that vitamin A deficiency can increase your risk of developing acne.
This is because it causes an overproduction of the protein keratin in your hair follicles, according to studies.
Furthermore, this can increase your risk of acne by making it more difficult for dead skin cells to be removed from hair follicles, thus, leading to blockages.
Some vitamin A-based medications are also available with a prescription.
Isotretinoin is one example of an oral retinoid.
It is effective in treating severe acne.
However, this medication can have serious side effects and you should take it under medical supervision.
5# Supports Bone Health
One of the key nutrients your body needs to maintain healthy bones is protein, calcium, and vitamin D.
However, eating vitamin A is also crucial for proper bone growth and development.
Moreover, a deficiency in this vitamin is also linked to poor bone health.
People with lower blood levels of vitamin A are at a higher risk for bone fractures than people with healthy levels, according to studies.
A meta-analysis of observational studies indicates that people with the highest amounts of vitamin A in their diet show a decrease in risk of fractures.
Yet, low levels of vitamin A may not be the only problem with it comes to healthy bones.
Some studies indicate that people with high intakes of vitamin A have also a lower risk of fractures.
However, these findings are all observational studies and cannot determine cause and effect.
This means that the link between vitamin A and bone health is not clear.
And more studies can help to confirm this link.
It is important to note that vitamin A alone does not determine your risk of fractures.
And the impact of the availability of other nutrients such as vitamin D also plays a role.
6# Promotes Healthy Growth and Reproduction
Vitamin A important for maintaining a healthy reproductive system in both men and women.
Moreover, it helps to make sure the normal growth and development of embryos during pregnancy.
Rat studies indicate the importance of vitamin A in the male reproductive system.
It states that a deficiency can block the development of sperm cells causing infertility.
In the same way, animals studies suggest that vitamin A deficiency in females can affect reproduction.
It does so by reducing egg quality and affecting egg implantation in the womb.
In pregnant women, vitamin A is also involved in the growth and development of different organs and structures of the unborn child.
It includes the skeleton, nervous system, heart, kidneys, eyes, lungs, and pancreas.
Though much less common deficiency, too much vitamin A during pregnancy can be harmful to the growing baby and can lead to birth defects.
Thus, according to different health authorities, women should avoid foods that contain concentrated amounts f vitamin A.
These include pâté and liver as well as supplements that contain vitamin A while conceiving.
Vitamin A Deficiency
Although vitamin A deficiency is rare, it is common in developing countries.
This is because such countries have limited access to food sources of preformed vitamin A and provitamin A carotenoids.
Moreover, it can lead to severe health complications.
According to WHO, vitamin A deficiency is one of the leading causes of preventable blindness in children around the world.
Vitamin A deficiency can also increase the severity and risk of dying from infections like measles and diarrhea.
Furthermore, vitamin A deficiency can raise the risk of anemia and death in pregnant women.
And negatively affect the fetus by slowing the growth and development.
On the other hand, less severe symptoms of vitamin A deficiency include skin issues like hyperkeratosis and acne.
Certain groups, however, are more at risk of vitamin A deficiencies.
These are infants, people with cystic fibrosis, pregnant or breastfeeding women in developing countries.
Food Sources of Vitamin A
There are a number of dietary sources of both preformed vitamin A and provitamin A carotenoids.
Preformed vitamin A readily absorbed in your body and it utilizes this vitamin than plant-based sources of provitamin A carotenoids.
The ability of your body to effectively convert carotenoids like beta-carotene into vitamin A depends on multiple factors.
These factors are genetics, diet, overall health, and medications.
For this very reason, if you follow a plant-based diet, especially a vegan diet, you should be vigilant about getting enough carotenoid-rich foods.
Some of the foods highest in preformed vitamin A are:
Egg yolks, beef liver, liverwurst, butter, cod liver oil, chicken liver, salmon, cheddar cheese, liver sausage, trout, and king mackerel.
Moreover, foods that are high in provitamin A carotenoids like beta-carotene are:
Sweet potatoes, pumpkin, carrots, kale, spinach, dandelion greens, cabbage, swiss chard, red peppers, collard greens, parsley, butternut squash.
Toxicity and Dosage Recommendations
Just like vitamin A deficiency can have negative effects on your health, consuming too much of it can also be dangerous.
The recommended daily allowance, RDA for vitamin A is 900mcg and 700 mcg for men and women respectively, daily,
However, it is important to avoid exceeding the tolerable upper limit, UL of 10,000 Iu or 3,000 mcg to prevent toxicity in adults.
It is also possible to consume excessive preformed vitamin A through animal-based sources.
These include the liver. The toxicity is linked to excessive supplement intake and treatment with certain medications like Isotretinoin.
Since it is a vitamin that is fat-soluble, your body stores them in the body and can reach unhealthy levels over time.
Moreover, taking too much of this vitamin can lead to serious side effects and can be even fatal if you ingest it at extremely high doses.
Signs and Symptoms of Vitamin A Toxicity
Acute vitamin A toxicity can occur over a short period of time when a single, excessive-high dose is consumed.
While chronic toxicity occurs when the disease is more than 10 times the RDA ingested over a longer time span.
The most common side effects of chronic vitamin A toxicity are referred to as hypervitaminosis A.
Vision disturbances, joint, and bone pain, poor appetite, nausea, confusion, itchy skin, and vomiting.
Additionally, sunlight sensitivity, hair loss, headache, dry skin, liver damage, jaundice, delayed growth, and a decrease in appetite are some other symptoms.
Though less common than chronic vitamin A toxicity, acute vitamin A toxicity is associated with more severe symptoms.
These are river damage, increase in cranial pressure, and even death.
Furthermore, this toxicity can negatively affect maternal and fetal health leading to birth defects.
In order to avoid toxicity, steer clear of high doses of vitamin A supplements.
The Ul for vitamin A applies to animal-based food sources of vitamin A and its supplements.
A high intake of dietary carotenoids is not associated with toxicity.
Though studies link beta-carotene supplements with an increase in the risk of lung cancer and heart disease in smokers.
As too much this vitamin can be harmful, make sure to consult with your doctor before taking the supplements.
Vitamin A is a fat-soluble nutrient that is important to your immune function, ee health, reproduction, and detail development. Bith its deficient and high dosage can cause severe side effects.
While it is important to meet the RDA of 700 to 900mcg daily for adults, make sure to never exceed the upper daily limit of 3,000mcg. With a healthy, and well-balanced diet, you can provide your body with the same amount of this nutrient.
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