Vitamin A is a fat-soluble element, a powerhouse of antioxidants which plays a pivotal role in all bodily functions. The active constituents of Vitamin A consist preformed Vitamin A or retinoids like retinol, retinal, retinoic acid and provitamin A carotenoids like β-carotene, alpha-carotene, gamma-carotene and xanthophyll beta-cryptoxanthin.

Vitamin A is naturally available in two dominant forms:

Retinol, also termed as Vitamin A1 is one of the key ingredients of Vitamin A. It is acquired from animal-based food sources is extremely beneficial in treating and preventing xeropthalmia – drying of the cornea.

Carotenoids, also known as tetraterpenoids are generally found in plant-based food sources. The carotenoids are converted into preformed Vitamin A by the body for  later use.

Functions Of Vitamin A


Vitamin A is a blessing for us as it provides a wide range of benefits. It is quintessential in maintaining healthy functions of our body. It strengthens our immune system, helps in treating eye problems and supports cell growth and development.

Vitamin A is mainly used for our eye health by improving our vision and treating night blindness, a condition where eyes are unable to perceive anything under dim or poor light.

The most promising benefit reaped from Vitamin A is the prevention and treatment of Xeropthalmia, a condition in which eyes fail to produce tears, drying up the conjunctiva or causing dry eye syndrome. If left untreated, it may eventually cause corneal damage and lead to complete loss of vision.

Apart from treating impaired vision, Vitamin A helps in strengthening and remodelling the bones, prevents osteoporosis and maintains the overall bone health.

It also plays a significant role in reproduction and infant development and also helps in improving male and female fertility.

Vitamin A is of pivotal importance in maintaining the immune system of our body. It helps in the production of white blood cells which in turn acts as a shield and protects our body from any invasion of infections or germs.

The most promising benefit of Vitamin A, in recent times has been found in the treatment of breast, lung and prostate cancer. People having a family history of cancer, have shown to exhibit lower risk of cancer while consuming Vitamin A regularly.

Vitamin A being a potent antioxidant is required for cell regulation. Researches show that, it controls the release of insulin by the cell into the blood stream and hence plays an upper hand in controlling diabetes.

Additionally, regular consumption of Vitamin A controls the production and secretion of oil in the skin and hair tissue and also ensures a beautiful mane and radiant skin.

Food Sources

Mother Nature has blessed us with innumerable dietary sources that contain Vitamin A. It is present in the food sources either in the form of Preformed Vitamin A which are fat soluble that are easily absorbed by the body or in the form of Provitamin carotenoids that get converted into active retinols and retinyl esters for better absorption by the body.

Vitamin A is abundantly present in the following food sources such as:

Foods source rich in vitamin A

Healthy Leafy Greeneries:

Vegetables which have a high content of Vitamin A mostly in the form of carotenoids are:

Spinach, turnip, broccoli, lettuce, parsley, kale and other leafy green veggies.

Carrot, tomatoes, sweet potato, pumpkin, squash, zucchini, red pepper and other orange and yellow coloured vegetables.

Apart from the veggies, certain orange and yellow coloured fruits are also loaded with Vitamin A like mango, orange, papaya, cantaloupes, pink or red grapes, watermelon, apricot, guava

Rich Content of active Vitamin A is also found in various food obtained from animal sources such as:

Dairy products like milk, cheese and butter

Animal-based food items like egg, fish oils and lean meat


Vitamin A deficiencies are very common due to lack of nutrition. The most common disease that happens due to absence of Vitamin A is xeropthalmia or night blindness. It may also reduce the growth and development of children and may risk the growth of foetus in pregnant women. Deficiency of Vitamin A may also make your body prone to infections and can cause several health and skin disorders.


Even though Vitamin A is absolutely must for a healthy body, intaking too much of it can lead to serious health hazards. The toxicity mostly happens due to preformed vitamins or retinoids. Preformed vitamins are fat soluble and are readily absorbed by the body. When we consume it in larger quantities, it is stored in the liver in the form of fats. And when too much of fat is accumulated in the liver, it becomes toxic for us.

The healthy intake of Vitamin A should be close to 600 I.U Retinol and 4800 I.U β-carotene. Anything more than this may lead to chronic toxicity exhibiting painful symptoms of Hypervitaminosis marked by eye irritation, sensitive eyes, bone, muscle or joint pain, headache, dry skin, constipation, confusion, nausea, vomiting, abdominal pain, hair loss, skin problems etc.

Acute toxicity may also cause severe health issues like liver problems, skin problems, foetal defects in pregnant women.

Though there are a list of benefits of Vitamin A, it is always advisable to take it within normal limits and get a prior consultation from a doctor or nutritionist while taking Vitamin A supplements.

Frequently Asked Questions

Can Excessive Intake Of Vitamin A Cause Toxicity?

Since Vitamin A is a fat-soluble vitamin, it stays in the body for a long time. When consumed through natural food options, it does not cause any side effect but in case Vitamin A is taken in excess in the form of supplements, i.e., more than the recommended amount, it can very well lead to toxicity in the body.

How To Protect One-Self From Vitamin A Deficiency?

Vitamin A deficiency can easily be avoided by eating adequate quantity of fresh fruits and veggies, especially the ones that are rich in this essential nutrient. Some of these include leafy greens, carrots, sweet potatoes, pumpkins, cantaloupes, mangoes, jackfruit, papaya, dairy products, fish and liver.

What Kind Of Complications Are Associated With Vitamin A Deficiency?

Complications associated with Vitamin A deficiency include:

  • Xerophthalmia
  • Night Blindness
  • Dry eyes
  • Keratitis
  • Microcytosis
  • Anisocytosis
  • Poikilocytosis
  • Keratomalacia
  • Bitot’s Spots

What Are The Different Tests That Can Be Done To Detect Vitamin A Deficiency?

Vitamin A deficiency can be identified chiefly by a panel of blood tests. One direct diagnostic test that helps find out the level of Vitamin A in the blood is Vitamin A blood test or Retinol test and Serum Retinol Level test.

What Are The Normal Recommended Test Values For Vitamin A Blood Tests?

Vitamin A blood test:

Deficiency: Less than 50 mcg/dL

Excess: More than 200mcg/dL

Serum retinol levels:

Deficiency: Less than 28µg/dL