Vitamin A: 5 Benefits of Vitamin A, Sources, and Daily Requirements

Vitamin A: 5 Benefits of Vitamin A, Sources, and Daily Requirements

Vitamin A is a vital micronutrient that keeps our bodies healthy.

Because it is not a nutrient the human body naturally produces, you must consume Vitamin A in your daily diet or by dietary supplements.

What is Vitamin A

Vitamin A isn’t actually a single vitamin, but instead is a group of fat-soluble compounds that can be stored in the body for later use.

These include retinol, retinal, and retinyl esters, which can be consumed in food or in dietary supplements (1).

Two forms of vitamin A is found in food – preformed vitamin A (retinol and retinyl esters) and provitamin A carotenoids (1). Preformed vitamin A is found in meat and animal by-products – like liver, dairy, and fish – while provitamin A carotenoids are found in plant foods – fruits, vegetables, and oils (1).

This micronutrient plays an important role in several vital body functions, which is why it needs to be consumed daily. These include supporting a healthy immune system, functioning as an antioxidant, keeping eyes healthy, strong hair skin and nails, and promoting fertility and fetal development.

5 Benefits of Vitamin A

  1. Healthy immune system support

Vitamin A boosts the immune system by stimulating immune response to illnesses and infections.

It is also involved in producing important immune cells (i.e., B-cells and T-cells) that help guide against disease.

  1. Functions as an antioxidant

Provitamin A carotenoids (from plant sources) have potent antioxidant properties (1).

These compounds fight free radicals that cause harmful oxidative stress on the body. They may prevent to some chronic disease and cognitive decline associated with oxidative stress (1).

  1. Keeps eyes healthy 

Vitamin A is essential for eye health.

In fetus, infant, and child health, vitamin A helps develop the eye tissue (macular tissue) (2).

As you age, vitamin A also helps keep eyes healthy and prevent disease like cataracts and blindness (2).

  1. Strong hair, skin, and nails

Vitamin A is most commonly associated with its effect on the skin – smoothing wrinkles and signs of aging – it also aids the hair and nails.

Vitamin A stimulates the production of sebum, which is a substance that prevents breakage (3).

It also strengthens and stimulates growth in thin, brittle nails.

  1. Promotes fertility and healthy fetal development

For both male and female reproduction, vitamin A is essential. It plays a role in both sperm and egg development (1).

It is also vital for placental health as well as healthy fetal tissue and cell development (1).

What is the daily requirement of Vitamin A

The recommended daily allowance (RDA) of vitamin A is 900 mcg per day for men and 700 mcg for women (1).

However, the tolerable upper limit (UL) of vitamin A is 3,000 mcg per day. It’s essential to stay under this limit, to avoid toxic levels within the body (1).

Vitamin A Deficiency And Toxicity

Vitamin A is an important vitamin for many functions of the body, but like any micronutrient, there are always risks of deficiency.

Symptoms of vitamin A deficiency include (2):

  • Dry skin
  • Acne breakouts
  • Irritated eyes
  • Poor wound healing
  • Infertility and difficulty conceiving
  • Impaired fetal growth
  • Night blindness

Opposite of deficiency, there is also the possibility of toxicity and chronic toxicity with vitamin A – also known as hypervitaminosis A.

Because it is a fat-soluble vitamin, all vitamin A derivatives – retinol, retinal, and retinyl esters – are stored in the body. If too much is consumed, it can cause potentially harmful side effects.

Interestingly, several symptoms of toxicity are similar or the same as those of vitamin A deficiency.

Symptoms may include (1):

  • Nausea and vomiting
  • Vision problems
  • Joint and bone pain
  • Sensitivity to sunlight
  • Hair loss
  • Dry and itchy skin
  • Delayed growth
  • Confusion
  • Jaundice

It is important to not that both deficiency and toxicity are rare, but understanding that the risks of each is important.

What are the best sources of Vitamin A?

Because Vitamin A is a vital nutrient, it’s important to meet the suggested intake recommendations every day via diet or dietary supplement.

As mentioned, two different forms of vitamin A is found in different food sources. Preformed vitamin A is found in meat and animal by-products – like liver, dairy, and fish – while provitamin A carotenoids are found in plant foods – fruits, vegetables, and oils (1).

Consult with a healthcare professional to discuss if you are consuming an adequate amount of vitamin A through your daily diet or are at risk for deficiency.

If you are having difficulties meeting your vitamin A daily intake requirements through your diet, supplements are also recommended.

Vitamin A can be found in most multivitamins, but is also available alone as a dietary supplement or in combination with other nutrients.

Always insure you are using reputable companies to source your vitamin A supplements and are not consuming over the daily UL, to avoid toxicity.

 

Author: Allison Lansman, RDN, LD

 

References

https://www.healthline.com/nutrition/vitamin-a

  1. https://www.healthline.com/nutrition/vitamin-a-deficiency-symptoms
  2. https://www.medicalnewstoday.com/articles/318403#7

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