Health Risks of Vitamin A Deficiency and Toxicity


Importance of Vitamin A

Vitamin A is an essential fat-soluble nutrient that the body requires to function properly. It plays a rather vital role in the body. More often than not, vitamin A can be found naturally in foods, but in cases where the amount of vitamin A in the food is not as much as is required by the body for proper functioning, opting in for vitamin A supplements is advised.

Vitamin A is a compound name for a group of other nutrients. These nutrients include; retinol, retinal, and retinyl esters. The two forms of vitamin A that are found in food are;

  • Preformed vitamin A (retinol and retinyl); is majorly found in animal products like fish, liver, and dairy.
  • Carotenoids vitamin A is found in plant produces like fruits, oils, and vegetables.

Due to the fact that vitamin A is fat-soluble, when taken into the body, it is stored in the tissues of the body for future use. However, most kinds of vitamin A are stored in the liver as retinyl esters. When these retinyl esters get broken down by the body, they are transported to the bloodstream, where your body can then use them.

This article comprises of the benefits of vitamin A, as well as its food sources. In addition, the effects of the deficiency and its toxicity are also elaborated on in this article. As harmful as vitamin A deficiency is, so is its toxicity. Toxicity occurs when vitamin A diets are taken over a long period of time, such that the body gets excess amounts of vitamin A content for its use. It also occurs when vitamin A supplements are used excessively and over a long period of time.

Functions of Vitamin A

  • Vitamin A helps supply healthy cell and bodily growth.
  • It strengthens the immune system.
  • It helps with vision and supports fetal development.
  • It protects the skin, cornea, intestines, bladder, and inner ear.
  • It also supports healthy female and male reproduction.

Health Benefits

The following are the benefits of vitamin A

Effective Antioxidant

Vitamin A contains antioxidant properties that help the body combat free radicals. Free radicals are molecules that can cause harm to your body by creating oxidative stress. Oxidative stress on its own can lead to various kinds of illnesses such as diabetes, heart disease, cancer, and memory decline. Foods that are high in vitamin A have helped lower the risks of developing chronic health conditions.

Eye Health

Vitamin A is an essential eye nutrient. It strengthens the cornea and provides clear vision. It prevents the eyes from chronic eye diseases like macular degeneration that is usually associated with old age. A high level of vitamin A in the body can help lower the risk of age-related macular degeneration by about 30%. This is possible by its ability to reduce oxidative stress.


As a result of its antioxidants nature, vitamin A has the ability to lower the risks of some kinds of cancer. It somehow hinders the growth of cancer cells, especially in areas like the breast, bladder, and ovaries.

Fertility and Fetal Development

Vitamin A is a really important nutrient that helps with both male and female reproduction and fertility. This is so because it plays an important role in the development of eggs and sperm cells. It is also effective in the healthy growth and development of a fetus, the placenta, and the tissues and walls that support the fetus carriage. In other words, vitamin A is important for both people that want to conceive, as it can help with their fertility and reproduction, and it is important for pregnant women and their fetuses as it provides healthy fetal development, growth, and maintenance.

Immune System

Vitamin A strengthens the immune system, which in turn helps protect the body from infections and illnesses. Vitamin A helps with the production of cells, which include B and T cells that play important roles in the guarding of the immune system. When a person suffers from vitamin A deficiency, inflammatory compounds begin to form within the body, and these compounds weaken the immune system in return.


  • Vitamin A deficiency occurs when the body does not get the required amount of vitamin A it needs to function properly. This could be a result of low vitamin A content in your diet. This, however, can be unhealthy for you as it exposes your body to a number of illnesses and chronic health complications.
  • According to research, one of the most noticed and most preventable causes of blindness in children is vitamin A deficiency.
  • Vitamin A deficiency is also known to be a major factor that exposes young children to the risks of illnesses like diarrhea and measles.
  • This deficiency inhibits the growth, development, and maintenance of the fetus and can lead to the possible death of the pregnant woman.
  • Vitamin A deficiency can trigger severe skin symptoms like hyperkeratosis.
  • People in the following group are more likely to suffer from vitamin A deficiency;
  • Premature children
  • A pregnant and breastfeeding mother
  • People who are sick with cystic fibrosis
  • In other words, lack of vitamin A in the body can lead to blindness, especially in children. It can also cause skin issues, expose you to the risk of being infected by antibodies and lead to complications during pregnancy.

Vitamin A Food Sources

There are quite a number of food sources that have been identified to richly contain vitamin A.

home remediesAs discussed above, preformed vitamin A is easily absorbed by the body than carotenoids vitamin A. Your body’s ability to absorb carotenoids depends on a number of factors, which include; overall health, medication, diet, and genetics. As a result of this, vegans and vegetarians should ensure that their plant-based foods have enough carotenoid contents to serve them. Non-vegetarians can, on the other hand, easily get vitamin A and are lucky enough (if they stick to vitamin A rich food sources) to have the kind of vitamin A that gets absorbed easily in their diet choices.

Preformed vitamin A rich food sources include;

Carotenoids vitamin A-rich foods include;

  • Cabbage
  • Collard greens
  • Parsley
  • Kale
  • Carrots
  • Pumpkin
  • Sweet potatoes
  • Spinach
  • Dandelion greens
  • Swiss chard
  • Red peppers
  • Butternut squash

For people who have chronic vitamin A deficiency, vitamin A supplements are advised by medical practitioners to be taken in certain doses to complement the vitamin A diet.


  • As much as vitamin A deficiency is harmful to the health, its toxicity is quite as dangerous. The appropriate dosage for every vitamin A supplement as advised by medical practitioners is 900mcg for men and 700mcg for women.
  • Although vitamin A toxicity can occur as a result of excess vitamin A content in diets. However, vitamin A toxicity is majorly associated with the excessive and prolonged usage of vitamin A supplements.
  • Because vitamin A gets stored in the tissues of the body before getting absorbed, it is possible that there can be an unhealthy accumulation of vitamin A in your tissues, thereby leading to toxicity in the process.
  • Ingesting an overdose of vitamin A supplements can cause serious side effects and can sometimes lead to death.

The following are the possible effects of acute vitamin A toxicity;

  • Delayed growth
  • Sensitivity to sunlight
  • Nausea
  • Lack of appetite
  • Hair loss
  • Confusion
  • Itchy skin
  • Dry skin
  • Bone and joint pain
  • Headachecaffeine withdrawal
  • Jaundice
  • Liver damage

Chronic vitamin A toxicity effects may include;

  • Cranial pressure
  • Liver damage
  • Sometimes death
  • Vitamin A toxicity can also affect pregnant women and disrupt the growth and development of their fetuses, and this can, in turn, lead to birth defects and sometimes stillbirth.

It is advisable to seek advice from your doctor before undergoing any vitamin A diet routine in order to better understand the appropriate vitamin A dosage required by your body, especially when you are pregnant, to prevent deficiency or toxicity.

In conclusion, vitamin A is an essential fat-soluble nutrient required by the body to supply the body with a healthy immune system, healthy eyesight, fertility in both males and females, as well as healthy growth, development, and maintenance of the fetus.  Both the excessive intake and its deficiency can cause negative effects on the body; this is why it is advised to speak to medical practitioners to understand the composition and dosage of every vitamin A supplement, especially during pregnancy. Getting Vitamin A from organic foods is healthier, and these vitamin A-rich foods are just enough to provide you with the appropriate amounts of vitamin A your body needs.