What does vitamin A do in the human body?

Everything You Should Know About Vitamin A

Vitamin A also known as Retinol is a fat-soluble vitamin. It plays a vital role in the growth and maintenance of the normal functions of the body as well as It consists of Retinol, retinal, pro vitamin A that is the carotenoids.  Retinol is also an excellent antioxidant that helps to eradicate free radicals from the body, which leads to an improvement in overall health. In addition to it has a significant role in maintaining good vision, skin and bones.

Brief Discovery 

Frederick Gowland Hopkins, a biochemist in 1912, discovered an unknown factor in milk which helped in the growth process of rats. Elmer McCollum, Lafayette Mendel and Thomas Osborne also had a role in this discovery. Later on, David Adriaan Van Dorp and Jozef Ferdinand Arens synthesized it in 1947.


Source, Requirements and Importance


Found in many foods especially in milk fat(18%DV), beef(8%DV) , pork(6%DV),fish(25%DV), fish liver oils(150%DV),collard greens(32%DV),eggs(15%DV),broccoli leaves(22%DV), sweet potatoes(12%DV),butter(11%DV),spinach(18%DV), pistachios(12%DV).

Beta carotene are usually found in bright coloured foods such as carrots(44%DV),apricots(4%DV),pumpkin(22%DV) and dark leafy vegetables (42%DV).

Daily-intake Requirement:

0–6 months                 –           400 mcg RAE

7–12 months               –           500 mcg RAE

1–3 years                     –           300 mcg RAE

4–8 years                     –           400 mcg RAE

9–13 years                   –           600 mcg RAE


Ages 14–18 years: 

Male                            –           900 mcg RAE

Female                         –           700 mcg RAE

In Pregnancy               –           750 mcg RAE

During lactation          –           1,200 mcg RAE


Ages 19–50 years

Male                           –           900 mcg RAE

Female                         –           700 mcg RAE

In Pregnancy               –           770 mcg RAE

During lactation          –           1,300 mcg RAE


Ages 51+ years:

Male                            –           900 mcg RAE

Female                         –           700 mcg RAE



It has so many functions in the body, including:

  • Helps in the functioning of the eyesight
  • Helps to maintain immunity and has many skin benefits.
  • Development of the fetus during pregnancy.
  • Helps in the formation of Rhodopsin pigment, which is necessary for the adjustment of night vision.

Deficiency and Related Symptoms:

When the serum levels of Retinol in the body are below 28μg/dL as it is considered a deficiency of vitamin A. The condition can occur due to poor dietary habits as well as can cause various disorders and diseases. Some of the causes of vitamin A deficit include the inability to absorb Vitamin A from the gastrointestinal tract due to bile duct disorder[A1], cirrhosis of the liver, celiac disease.


Effects of Vitamin A Deficiency:  Overdose of the vitamin may cause:

Xerophthalmia- A condition in which the production of tears does not occur.

Bitot’s Spots –  The build-up of keratin in the eye.

Night Blindness- Complete loss of ability to see at night (even if low light is present)

Growth – Growth retardation also occurs in some cases.

What To Take To Counter Deficiency?

A balance is required in the intactness of vitamins in the body So, to counter the deficiency, you can have the following:

Vitamin A Dry:

It helps in promoting eye health, shows antioxidant activity not only-but also  helpful for increasing immunity.

Now supplements (Vitamin A):

It contains fish liver oil as a supplement, and its dose is usually taken as one soft gel per day.[A2]

Bronson Vitamin A:

Supports the immune system and helps vision health by supplementing Vitamin A.

There are various other vitamin A supplements moreover multivitamins can also be used for deficiency.

The direction of Use:

Always take medicines after consulting your doctor in addition to pregnant women should be cautious while taking it.

Overdose And Adverse Reactions:

Most of the Vitamin A tablets can cause any of the overdose toxicity as a result can lead to nausea, vomiting, anorexia, irritability, increased intracranial pressure, alopecia bone and joint pain, hepatic impairment, anaphylactic shock, itching, dermatitis, exfoliation as well as headache.


Contraindication And Drug Interaction

The contraindication is usually found in Hypervitaminosis A and Hypersensitivity. Bexarotene helps in treating cancer. The side effect is found to be dry or itchy skin. Use with anticoagulant drugs may increase the risk of bleeding.



Human body must have Vitamin A or Retional. Dairy products and leafy vegetables are a good source of Vitamin A.

Night blindness is the main result of the deficiency of Vitamin A. It helps in stimulating and regenerating the skin and helps against oxidation. It is advisable to take sufficient this in a balanced diet.