Vitamin A is an important nutrient that plays a role in many crucial bodily functions. A deficiency may occur when a person does not get enough vitamin A to cover their body’s needs, and may lead to troubling symptoms.
Dietary intake is the simplest way to access enough vitamin A for most people. In some cases, doctors may recommend supplements or other forms of vitamin A to help replenish very low stores.
Keep reading to learn about the causes and symptoms of vitamin A deficiency, why vitamin A is important, and some foods that are rich in vitamin A.
Symptoms of vitamin A deficiency may differ in severity, and some people may have more serious symptoms than others. Below are some possible symptoms people may experience:
Issues related to vision
According to the American Academy of Ophthalmology, vision issues are common in those with vitamin A deficiency.
The eyes may become very dry at first, which may damage the cornea and retina.
Night blindness may also occur as a result of vitamin A deficiency. This causes the person to be unable to see or have trouble seeing in low light, eventually leading to complete blindness at night.
The World Health Organization (WHO) note that night blindness is one of the first signs of vitamin A deficiency.
In severe cases, the eye continues to dry out, and tissues may build up in the cornea. This in turn may lead to the cornea becoming hazy, developing lesions, and being destroyed.
Vitamin A plays a key role in immune function. A person with a vitamin A deficiency may experience more frequent infections, as they cannot fight off these infections as easily.
Some people with vitamin A deficiency may notice problems with their skin, such as dryness, itching, and scaling. Some may experience similar issues on the hair and scalp as well.
Vitamin A plays a part in creating healthy cells. Not having enough of the key vitamin may delay growth or cause children to experience stunted growth or slow bone growth.
The cause of vitamin A deficiency is not getting enough vitamin A in the body or having an underlying issue that results in the body not absorbing or utilizing vitamin A effectively.
According to the World Health Organization (WHO), vitamin A deficiency is rare in developed nations, such as the United States, and common in developing nations, where people do not have as much access to vitamin A.
Some people may be more at risk of vitamin A deficiency, including:
- premature infants
- pregnant or lactating people
- infants and young children in developing countries
Additionally, a secondary deficiency may occur in people who have underlying issues that interfere with the body’s ability to use vitamin A, such as those with:
Young children and pregnant people in low income countries are at the highest risk of severe effects from vitamin A deficiency.
Vitamin A plays a significant role in many functions in the body. The National Institutes of Health (NIH)note that vitamin A is important for the function of:
- the immune system
- the reproductive system
- cellular communication
There is an important link between vitamin A and vision. In addition to helping create the membranes of the eye and cornea, vitamin A is a key compound of a protein in the body called rhodopsin, which absorbs light in the retina.
Vitamin A also plays a crucial role in cell growth in other areas and helps with the normal formation and functioning of the cells in the heart, lungs, kidneys, and other organs.
There are two forms of vitamin A in the human diet. The first is preformed vitamin A, such as retinol, which comes from animal sources, including meat, fish, and dairy.
The second form is provitamin A carotenoids, such as beta carotene. These compounds are not usable forms of vitamin A as they exist naturally, but the body converts them into a usable form of vitamin A.
Both forms of the vitamin will go through an additional metabolization in the body, becoming active retinal and retinoic acid.
There are a number of simple dietary sources of vitamin A. This includes both plant and animal sources, so it is typically easy to meet intake recommendations when following a healthful, balanced diet.
The NIH list a number of plant and animal sources of vitamin A and their values.
Plant sources of vitamin A include:
- baked sweet potato: 1,403 micrograms (mcg) per whole potato
- boiled spinach: 573 mcg per 1/2 cup
- raw carrots: 459 mcg per 1/2 cup
- raw cantaloupe: 135 mcg per 1/2 cup
- raw mango: 112 mcg per whole mango
- raw sweet red peppers: 117 per 1/2 cup
- fortified breakfast cereal: 90 mcg per serving
Animal sources of vitamin A include:
- beef liver: 6,582 mcg per 3 ounces (oz)
- ricotta cheese: 263 mcg per cup
- Atlantic herring: 219 mcg per 3 oz of picked fish
- fat-free or skim milk with vitamin A added: 149 mcg per cup
- hard-boiled egg: 75 mcg per egg
Vitamin A also comes in various forms as a dietary supplement. Doctors may recommend taking a supplement if a person has difficulty getting enough vitamin A from their daily diet.
These supplements may contain preformed vitamin A or other forms, such as beta carotene, or a mixture of the two.
Anyone who is concerned about their vitamin A levels may wish to contact their doctor to have these levels checked. This may help diagnose any underlying condition.
People with underlying conditions that may put them at risk of various deficiencies should regularly check in with their doctor to keep an eye on their vitamin levels and make any necessary adjustments.
While the WHO note that vitamin A deficiency is rare in developed nations, where people have access to many foods rich in vitamin A, it may still occur in some people. Anyone who notices the signs of severe deficiency, such as nighttime blindness, should contact a doctor immediately.
Vitamin A is a fat-soluble vitamin, meaning the body stores it in its tissues. It is possible to take too much vitamin A, which can lead to serious side effects. A person should avoid taking high-dose vitamin A supplements unless prescribed and monitored by a healthcare professional.
Vitamin A deficiency is not common in places with access to common foods rich in vitamin A. However, deficiency can occur in cases where people cannot easily access these foods or where other issues cause the vitamin A to be unavailable.
Children and pregnant or breastfeeding people in low income countries have the highest risk of severe complications from vitamin A deficiency.
If a person is concerned about their symptoms or has an underlying condition that may disrupt their vitamin A intake, they should contact a doctor.