5 science-backed benefits of vitamin A and best food sources, according to nutritionists

• Vitamin A benefits include maintaining eye health, treating acne, and supporting the immune system.
• Foods high in vitamin A include carrots, sweet potatoes, and pumpkin.
• Adult men should take 900 micrograms (mcg) of vitamin A daily whereas adult women should take 700.

Vitamin A is a fat-soluble, essential vitamin. Vitamin A helps the eyes, immune system, and organs function properly. It is available through animal and plant-based foods.

Here are five science-backed benefits of vitamin A and how much you should be eating each day.

1. Preserves eyesight

Vitamin A is important for maintaining night and dim light vision because it forms pigments - molecules that help you see color - in your eye that are required for night vision.

Without vitamin A, your eyes stop producing these pigments, which can eventually lead to night blindness. This condition causes difficulty adjusting to dim light or a complete inability to see in the dark.

"Vitamin A also plays a role in protecting the cornea, the clear outer layer of the eye. This can reduce the risk of developing cataracts, which cause cloudy vision," says Julienna Hever, MS, RD, CPT, a registered dietitian specializing in plant-based diets based in Southern California.

Cataracts are a common eye condition that affects over half of the people in the US over the age of 80.

According to the Age-Related Eye Disease Study sponsored by the National Eye Institute, vitamin A supplements - in addition to other vitamins that have antioxidants and zinc - may protect eye health in those with certain diseases.

The study included 4,757 participants aged 55 to 80 years old affected by cataracts, age-related macular degeneration, or both. Age-related macular degeneration is a condition that causes central vision loss, meaning details in objects directly in front of a person may appear blurry.

Participants were divided into four groups and given a daily oral supplement for five years. Each group received one of the following supplements:

• Antioxidant formulation (which contained 15 mg of vitamin A), zinc, and copper
• Zinc and copper
• Just the antioxidant formulation
• A placebo

The antioxidant formulation with zinc and copper slowed the progression of age-related macular dysfunction from intermediate to advanced by 25%, compared to 21% in those taking the minerals, and 17% in those taking the antioxidants. It also reduced the risk of vision loss by 19%.

2. Helps the immune system function

Vitamin A is needed by your immune system for growing, maintaining, and strengthening epithelium and mucous tissues that line the majority of our organs. These tissues are the body's first line of defense against pathogens and are a key part of the body's innate immune response to infection.

Related Article Module: Why antioxidants are so important to your overall health

Vitamin A also has antioxidant properties. Antioxidants prevent cells from becoming damaged in a process known as oxidative stress. Continual cell damage from oxidative stress can lead to chronic diseases such as cancer, heart disease, and vision loss.

However, supplementary or extra vitamin A has not proven to be beneficial unless you are deficient. That said, diets high in plant-based vitamin A happen to be what most nutrition experts agree are best for you.

3. Supports organ function

Normal amounts of vitamin A help the heart, lungs, and kidneys function by promoting the growth of healthy cells and tissues.

For example, a 2018 review published in Nutrients found that vitamin A plays an integral role in the development and maturation of lung tissue, thereby promoting overall lung functioning. The same review found that deficiency in vitamin A is associated with an increased risk of developing lung problems such as asthma and respiratory infections like pneumonia and the flu.

4. Reduces and treats acne

How vitamin A may help treat acne, reduce wrinkles, and support skin health

A type of vitamin A, available by prescription or in small doses in over-the-counter products, called retinol is considered one of the best topical treatments for acne. In fact, the guidelines for the care and treatment of acne set by the Journal of the American Academy of Dermatology suggest applying topical retinoids or retinol products as the first line of treatment for mild to severe acne.

Acne usually occurs when pores in the skin become clogged with dead skin cells and oils. Retinol treats acne by acting as an extreme exfoliator, removing these dead skin cells, and in turn promoting the growth of new cells - a process called cell turnover.

Topical retinol may be harsh on the skin as common side effects are itching, redness, or dryness. Some ways to reduce irritation include:

• Applying one thin layer of retinol rather than thick layers or multiple applications
• Apply the cream or gel every other day for the first two to four weeks
• Using a gentle moisturizer

Be sure to apply sunscreen whenever using retinol products on the skin, as they make you more prone to sunburn and sun damage. Read more about finding the right facial sunscreen for you based on your skin type.

5. Helps a healthy pregnancy

Getting enough, but not too much, vitamin A during pregnancy is important for fetal development.

A 2010 study published in the New England Journal of Medicine found that vitamin A supplementation in chronically undernourished women before, during, and after pregnancy improved lung function in offspring.

Researchers compared the lung capacity of 1,371 children whose mothers received either a vitamin A supplement or a placebo. Once the children reached nine to 13 years old, the researchers examined their lung function and found that those whose mothers received vitamin A supplementation had stronger lungs than the children of the women who did not.

However, the World Health Organization recommends vitamin A supplementation only for pregnant women in areas where vitamin A deficiency is considered a severe public health problem. That's because too much vitamin A can cause birth defects.

Most pregnant women should aim to get their vitamin A intake from a healthy diet. However, Susan Dopart, a registered dietitian-nutritionist in Los Angeles who specializes in pregnancy, says that if your healthcare provider recommends a supplement, a multivitamin or prenatal vitamin should provide sufficient amounts of vitamin A during pregnancy. Discuss any supplements you take during pregnancy with your doctor, first.

How much vitamin A do I need?

How much vitamin A you need depends on a variety of factors including your age, sex, and whether or not you're pregnant or breastfeeding.

How to incorporate more vitamin A into your diet

Getting enough vitamin A shouldn't be an issue if you're eating a varied, healthy diet. Therefore, most people will not need to consider taking a vitamin A supplement.

"Unlike vitamin D or zinc, vitamin A is commonly found in foods, which is why deficiency rates for Vitamin A are pretty low," says Dopart.

There are two types of vitamin A that can be found in foods:

1. Retinols are absorbed and stored in fat once consumed. The body doesn't need to convert them into vitamin A.
2. Beta-carotenes are converted into vitamin A through biochemical processes in the body. "Beta-carotene rich foods are usually brightly colored fruits and vegetables," says Hever.

Foods rich in either type of vitamin A include:

Insider's takeaway

Vitamin A is essential for the overall health of your organs and especially important for a healthy pregnancy. If you are eating a varied diet with meat, dairy, and vegetables, you should easily be hitting your daily dose of vitamin A. If you are concerned about your vitamin A intake, talk to your healthcare provider or a registered dietitian.

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