There are More Health Benefits of Vitamin A Than You Can Count. Learn How Vitamin A Boosts Your Immune System.
Vitamin A is derived from a wide range of plant and animal sources and is used to regulate your vision and cell growth in your body. There are several other health benefits of Vitamin A that are essential for your body.
Read on to find out the different health benefits of Vitamin A.
What is Vitamin A and what does it do?
Vitamin A is a fat-soluble vitamin that is required for several bodily functions. It is needed to maintain good vision and a healthy immune system, as well as for growth and development.
Vitamin A also promotes the activity and function of white blood cells, helps maintain healthy endothelial cells, takes part in remodeling bones, and regulates cell growth and division needed for reproduction and foetal development. It also has antioxidant properties.
Forms of Vitamin A
Vitamin A is present in animal foods as Preformed vitamin, Retinol, or Retinyl Esters.
Carotenoids are yellow-orange pigments in plant foods. Some of them (alpha-carotene, beta carotene, and beta-cryptoxanthin) are precursors of vitamin A, which means that they get converted in our body into retinol. They are also known as Provitamin A.
Retinoid is a term used for compounds related to or which have the same properties as Vitamin A and include Retinol (alcohol form), Retinal (aldehyde form), and Retinoic acid (acid form).
Up to 90% of the retinoids can be absorbed from the diet, depending upon the amount of fat in the diet.
Preformed vitamin A comes from animal products, vitamin supplements, and fortified foods. Carotenoids are found naturally in plant foods, apart from that there are some other carotenoids of physiological significance which include lycopene, lutein, and zeaxanthin.
Now let’s see what are the benefits of Vitamin A, its dietary sources, its deficiency & toxicity and what are the different forms available, and its possible drug interaction.
Health benefits of Vitamin A
One of the primary benefits of vitamin A is maintaining good vision.
In the retina of the eye, Retinol gets converted to Retinal and is involved in the eye’s ability to see under low light conditions. Thus a deficiency results in a decrease in the detection of low-level light, a condition referred to as night blindness .
In rare cases, prolonged insufficient intake of dietary vitamin A can also cause complete vision loss.
2) Immune system
Vitamin A is involved in the development of the immune system, particularly in T cell differentiation and proliferation.
It’s also involved in the function and production of white blood cells, which help fight infection, clear bacteria and other pathogens from your bloodstream, because of its critical role in enhancing immune function, it is also known as an anti-inflammatory vitamin .
3) Growth & Reproduction
Vitamin A is essential for the maintenance of both male and female reproductive systems.
Its deficiency in children has been linked to growth retardation and in the foetal stages of life, vitamin A is particularly required for heart, limb, eye, and ear development, but too much vitamin A in the diet of pregnant women has been linked to birth defects  .
4) Development and Maintenance of Bone
This is especially dependent on an adequate amount of vitamin A. The synthesis of bone protein and thus the enlargement of bone is thought to require vitamin A and D.
And studies suggest that people with lower blood levels of vitamin A are at a higher risk of bone fractures than people with healthy levels .
5) Skin Health
Skin is a major retinoid-responsive tissue.
Retinol stimulates the production of new skin cells and currently, the retinoic drug isotretinoin is the most commonly prescribed agent in the treatment of acne.
Vitamin A serums help to regulate the sloughing off of skin cells, reducing the occurrence of clogged pores, fine lines.
Topical retinoids stimulate collagen production, making them effective at reducing the appearance of fine lines and wrinkles. These can also help to even out skin tone by fading age spots .
All cells in the body including the ones on our head need Vitamin A for growth. Vitamin A supports the secretion of sebum, which is a substance that prevents hair breakage and moisturizes the scalp and helps keep hair healthy. However, some research has found that taking too much vitamin A can lead to hair loss .
7) Other benefits
Due to their antioxidant properties, carotenoid-rich fruits and vegetables may protect against certain types of cancers, and Vitamin A in the form of retinoic acid is also essential for gene transcription.
How much vitamin A do I need?
The total Vitamin A content of any dietary source is usually expressed as micrograms (µg) of retinol equivalents (RE).
The Recommended Dietary Allowance (RDA) of Vitamin A for men and women is 900 and 700 μg retinol activity equivalents (RE)/day, respectively, and the Tolerable Upper Intake Level (TUL) for adults is set at 3,000 μg/day of preformed vitamin A .
What happens if I take too little or too much Vitamin A?
Deficiency of Vitamin A
Vitamin A deficiency is rare in developed countries like the USA, but it’s common in developing countries like India and Africa especially children and pregnant women as these populations may have limited access to food sources of preformed vitamin A and provitamin A carotenoids.
Vitamin A deficiency increases the chances of getting infections like diarrhea and measles and also raises the risk of anemia in pregnant women .
Vitamin A deficiency can also cause blindness. Symptoms of Vitamin A Deficiency include night blindness, dry skin, and frequent infections.
Toxicity of Vitamin A
The Tolerable Upper Intake Level of preformed Vitamin A for adults is 3000 mcg/day. It is not possible to cross the Tolerable Upper Intake Level of Vitamin A through a balanced diet, however, consuming excess animal-based preformed Vitamin A or Vitamin A supplements can do so.
Vitamin A is a fat-soluble vitamin, it is stored in your body and can reach unhealthy levels over time. Taking too much vitamin A can be fatal if ingested at extremely high doses.
Another reason to avoid too much intake of preformed vitamin A is that it may interfere with the beneficial actions and functions of vitamin D. Signs of toxicity include the following.
- Vision changes such as blurry sight
- Bone pain
- Nausea and vomiting
- Dry skin
- Sensitivity to bright light like sunlight
Preformed vitamin A, beta-carotene is however not toxic even at high levels of intake. The body can form vitamin A from beta-carotene as needed, and there is no need to monitor intake levels as with preformed vitamin A .
Now that we’ve got an idea of the benefits of taking vitamin A, its deficiency, and its toxicity, let’s look at how we can get vitamin A.
Food Sources of Vitamin A
There are many dietary sources of both Provitamin A carotenoids and Preformed vitamin A. Preformed vitamin A is more readily utilized and absorbed by your body than any plant-based sources of provitamin A carotenoids.
Your body’s ability to effectively convert carotenoids, such as beta-carotene, into active vitamin A depends on many factors including:
- Overall health
For this reason, vegans or those who follow plant-based diets should be vigilant about getting enough carotenoid-rich foods.
Preformed vitamin A is found only in foods from animals, good sources include:
|Sources||Vitamin A/ 100g|
|Cod liver oil||1,00,000 IU|
|Beef liver||16,900 IU|
|Liver sausage||13,636 IU|
|Egg Yolks, raw||1,442 IU|
|Cheddar cheese||1,002 IU|
|King mackerel||727 IU|
Vitamin A in sweet potato or any other plant-based food is present as beta-carotene. A few plant sources of Vitamin A are  :
|Sweet potatoes||14,187 IU|
|Butternut squash||10,630 IU|
Vitamin A as a Supplement
Who needs supplements?
Most people get enough Vitamin A through a balanced diet, but some may struggle to do so. There are also certain conditions that can limit the absorption of dietary sources and a healthcare provider or nutritionist may advise taking supplements.
Individuals who may benefit from supplements include :
- Women who are pregnant or breastfeeding
- Exclusively or partially breastfed infants
- Adults or children with diagnosed nutritional deficiencies
- Individuals with conditions causing nutrient malabsorption
- People with restricted food access
- Some vegans and vegetarians
Things to consider while choosing a dietary supplement:
1) Look for active forms of nutrients- When you take the active form of a nutrient, you’re bypassing a step that your body would need to take care of for the nutrient to do its job.
2) Beware of fillers and additives– It is best to make sure that your supplement doesn’t contain added synthetic colors, fillers, and ingredients that you don’t recognize or understand. These are often added to extend a product’s shelf life, to make it seem more appealing, or to make it less expensive to manufacture.
3) Don’t go over your recommended Daily Value (DV) for vitamins and minerals unless your doctor says it’s okay.
4) Buy brands with USP, NSF, or another third-party “seal of approval.”
How do you take vitamin A supplements?
Some vitamins are best taken after a meal, while others are on an empty stomach. Establishing a routine of taking a vitamin at the same time every day will help form a healthy habit and will also help you get the most out of your vitamin supplement.
Topical application of Vitamin A
Topical retinoids have been in regular use in dermatology for a long time, and have been used to treat a variety of cutaneous disorders, such as hyperpigmentation, fine lines, photoaging, acne, and wrinkles are available via prescription and as over-the-counter formulations.
Vitamin A is a fat-soluble nutrient and a well-balanced diet is a great way to provide your body with a safe amount of this essential nutrient. It is vital for immune function, eye health, reproduction, and fetal development.
Most people can meet their needs for vitamin A through their diet, however, in some cases, a doctor may recommend supplements. Anyone who uses vitamin A supplements should take care to follow the doctor’s instructions, as some forms of vitamin A can be toxic in high doses.
Q: Can I take vitamin A every day?
A: The Recommended Daily Amount RDA of vitamin A is 700 mcg (2,333 IU) for adult women and 900 mcg (3000 IU) for adult men. So vitamin A can be consumed daily as long as you are not exceeding.
Q: What form of vitamin A is best?
A: Preformed Vitamin A (or retinol) found in animal sources is most readily absorbed in the body so it can be considered as the best form.
Q: What causes low vitamin A?
A: Common causes of Vitamin A include inadequate intake, fat malabsorption, or liver disorders.
Q: Do I need vitamin A supplements?
A: Most people do not need to take vitamin supplements and can get all the vitamins and minerals they need by eating a healthy, balanced diet.
Q: Does Vitamin A stay in the body?
A: Yes, vitamin A is fat-soluble, which means it can be stored in the body. Taking high doses of vitamin A over a long period of time can result in harmful levels in the body unless you have a medically diagnosed deficiency.
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