Introduction

Vitamin A is the name of a group of fat-soluble retinoids, primarily retinol and retinyl esters . Vitamin A is involved in immune function, cellular communication, growth and development, and male and female reproduction . Vitamin A supports cell growth and differentiation, playing a critical role in the normal formation and maintenance of the heart, lungs, eyes, and other organs . Vitamin A is also critical for vision as an essential component of rhodopsin, the light-sensitive protein in the retina that responds to light entering the eye, and because it supports the normal differentiation and functioning of the conjunctival membranes and cornea .

Health benefits

Vitamin A is an important nutrient that benefits health in many ways.

Potent antioxidant

Provitamin A carotenoids such as beta carotene, alpha carotene, and beta cryptoxanthin are precursors of vitamin A and have antioxidant properties.

Carotenoids protect your body from free radicals — highly reactive molecules that can harm your body by creating oxidative stress .

Oxidative stress has been linked to chronic conditions such as diabetes, cancer, heart disease, and cognitive decline .

Diets high in carotenoids are associated with a lower risk of many of these conditions, such as heart disease, lung cancer, and diabetes .

Essential for eye health and preventing macular degeneration

As mentioned above, vitamin A is essential to vision and eye health.

Adequate dietary intake of vitamin A helps protect against certain eye diseases, such as age-related macular degeneration (AMD).

Studies show that higher blood levels of beta carotene, alpha carotene, and beta cryptoxanthin may reduce your risk of AMD by up to 25% .

This risk reduction is linked to carotenoid nutrients’ protection of macular tissue by lowering levels of oxidative stress.

May protect against certain cancers

Due to their antioxidant properties, carotenoid-rich fruits and vegetables may protect against certain types of cancer.

For example, a study in more than 10,000 adults found that smokers with the highest blood levels of alpha carotene and beta cryptoxanthin had a 46% and 61% lower risk of dying from lung cancer, respectively, than nonsmokers with the lowest intake of these nutrients .

What’s more, test-tube studies demonstrate that retinoids may inhibit the growth of certain cancer cells, such as bladder, breast, and ovarian cancer cells .

Vital for fertility and fetal development

Vitamin A is essential for both male and female reproduction because it plays a role in sperm and egg development.

It’s also critical for placental health, fetal tissue development and maintenance, and fetal growth .

Therefore, vitamin A is integral to the health of pregnant people and their developing babies, as well as people who are trying to become pregnant.

Boosts your immune system

Vitamin A impacts immune health by stimulating responses that protect your body from illnesses and infections.

Vitamin A is involved in the creation of certain cells, including B cells and T cells, which play central roles in immune responses that guard against disease.

A deficiency in this nutrient leads to increased levels of pro-inflammatory molecules that diminish immune system response and function.

Deficiency

Though vitamin A deficiency is rare in developed countries such as the United States, it’s common in developing countries, where populations may have limited access to food sources of preformed vitamin A and provitamin A carotenoids.

Vitamin A deficiency can lead to severe health complications.

According to the World Health Organization, vitamin A deficiency is the leading cause of preventable blindness in children worldwide .

Vitamin A deficiency also increases the severity and risk of dying from infections like measles and diarrhea .

Additionally, research has found that vitamin A deficiency raises the risk of anemia and death in pregnant women and negatively impacts the fetus by slowing growth and development.

Less severe symptoms of vitamin A deficiency include skin issues such as hyperkeratosis and acne.

Certain groups — such as premature infants, people with cystic fibrosis, and pregnant or breastfeeding people in developing countries — are more at risk of vitamin A deficiency .

SUMMARY

Vitamin A deficiency can lead to blindness, increased infection risk, pregnancy complications, and skin issues.

Food sources

There are many dietary sources of both preformed vitamin A and provitamin A carotenoids.

Preformed vitamin A is more readily absorbed and utilized by your body than 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 genetics, diet, overall health, and medications.

For this reason, those who follow plant-based diets — especially vegans — should be vigilant about getting enough carotenoid-rich foods.

Foods highest in preformed vitamin A include:

• egg yolks
• beef liver
• liverwurst
• butter
• cod liver oil
• chicken liver
• salmon
• cheddar cheese
• liver sausage
• king mackerel
• trout

Foods high in provitamin A carotenoids like beta carotene include :

• sweet potatoes
• pumpkin
• carrots
• kale
• spinach
• dandelion greens
• collard greens
• winter squash
• cantaloupe
• papaya
• red peppers