Vitamin A Deficiency
What is vitamin A deficiency?
Vitamin A deficiency is when your body lacks the amount of vitamin A it needs to function properly. Vitamin A deficiency can cause vision loss and blindness. It can also lead to complications with your skin, heart, lungs, tissues and immune system.
Who does vitamin A deficiency affect?
Vitamin A deficiency is rare in the United States, but it can affect people who don’t get enough vitamin A in their diets. It also affects people with certain liver disorders and conditions that affect how their bodies can absorb vitamins.
In developing countries around the world, many people don’t get enough vitamin A. Infants, children and people who are pregnant or breastfeeding are the most at risk. Vitamin A deficiency is the leading cause of blindness in children around the world. Every year, between 250,000 children and 500,000 children worldwide become blind because of vitamin A deficiency.
What is vitamin A?
Vitamin A plays a key role in many systems of your body. Vitamin A is essential for healthy vision, metabolism and cell development. It’s an important factor in keeping your immune system and reproductive system healthy. Your body can’t make vitamin A on its own, so you must get it through the foods you eat.
Vitamin A is vital for your vision. Your eyes need to make specific pigments for your retinas to work correctly. A lack of vitamin A hinders your eyes’ ability to make these pigments, which can lead to night blindness. In other words, you need vitamin A to be able to see at night.
Your eyes also need vitamin A to produce moisture to keep your corneas properly lubricated. If your corneas get too dry, they can become damaged, which can lead to blindness.
Vitamin A also keeps your skin and the lining of your lungs, intestines and urinary tract in tip-top shape. Plus, it helps your immune system protect you against infections.
What are the different forms of vitamin A?
There are two forms of vitamin A.
Preformed vitamin A
Preformed vitamin A, or retinol, is found naturally in animal products, including beef, poultry, fish, liver and eggs. Some cereals and dairy products are fortified with vitamin A as well.
Provitamin A carotenoids
Carotenoids are from plant sources and are the pigments in vegetables and fruits that give them their yellow, orange and red colors. After you eat these fruits and vegetables, your body slowly converts the carotenoids into vitamin A. The most common type of carotenoid is beta-carotene.
What complications can occur due to vitamin A deficiency?
Vitamin A deficiency can lead to many complications, including:
- Eye problems: Vitamin A is a key factor in many functions of your eyes. Vision loss and blindness can occur.
- Skin issues: A lack of vitamin A can cause dry, scaly and/or itchy skin.
- Infertility: Vitamin A plays an important role in your reproductive system. Vitamin A deficiency can lead to trouble conceiving and infertility.
- Growth issues: Vitamin A deficiency can cause delayed growth and development in children.
- Respiratory tract infections: Vitamin A deficiency can cause problems with your immune system. This can lead to infections in your chest and throat.
Symptoms and Causes
What are the signs and symptoms of vitamin A deficiency?
One of the early signs of vitamin A deficiency is night blindness (nyctalopia). If you have night blindness, you have trouble seeing well in the dark, but you can see normally if enough light is present. A retinal disorder causes night blindness.
As the vitamin A deficiency worsens, the whites of your eyes and your corneas can become dry and you aren’t able to produce tears (xerophthalmia). Foamy spots called Bitot spots may appear in the whites of your eyes. Open sores on your corneas (corneal ulcers) may appear, or drying or clouding of your corneas (keratomalacia), which can lead to blindness.
What causes vitamin A deficiency?
Vitamin A deficiency occurs when you don’t get enough vitamin A in your diet. While rare in the United States, vitamin A deficiency happens frequently in developing countries around the world. People in impoverished nations don’t get enough food with vitamin A.
Vitamin A deficiency also occurs because of liver disorders. Your liver stores most of your body’s vitamin A, and liver disorders can interfere with vitamin storage.
Diseases and conditions that impair your intestine’s ability to absorb fat can also cause vitamin A deficiency. These conditions can reduce your body’s ability to absorb vitamins such as vitamin A. These conditions include:
- Chronic diarrhea.
- Celiac disease.
- Cystic fibrosis.
- Certain pancreatic disorders.
- Bile duct blockage.
- Zinc or iron deficiency.
- Small bowel bypass or bariatric surgery.
- Alcohol use disorder.
- Intestine or pancreas surgery.
Diagnosis and Tests
How is vitamin A deficiency diagnosed?
Your healthcare provider can diagnose vitamin A deficiency based on your symptoms and a blood test.
If you have night blindness, your healthcare provider may order an eye test called electroretinography. Your healthcare provider will examine the light-sensing cells (photoreceptors) in your retinas. The test measures the response of your retinas to flashes of light.
A serum retinol blood test can measure the amount of vitamin A in your blood. However, your body stores large amounts of vitamin A, so the level of vitamin A in your blood won’t decrease until your deficiency is severe (less than 20 micrograms per deciliter [mcg/dL]).
Vitamin A deficiency can be confirmed if your symptoms start to improve after taking a vitamin A supplement.
Management and Treatment
How is vitamin A deficiency treated?
Your healthcare provider will treat your vitamin A deficiency with high doses of a vitamin A supplement for several days. After several days, they’ll have you take lower doses of vitamin A until your vision and skin issues start to resolve. Vitamin A supplements can cure night blindness and help lubricate your eyes again. However, vision loss due to scarring from corneal ulcers can’t be cured.
Infants shouldn’t take high doses of vitamin A because it can be toxic to them. However, children can be treated with vitamin A supplements. Your child’s healthcare provider will determine the correct dosage.
Your healthcare provider can also help you plan a healthy, balanced diet that includes foods that contain vitamin A.
If you have a retinol level over 30 mcg/dL, supplementing vitamin A won’t be beneficial. Instead, just be sure to eat vitamin A-rich foods. Consuming high levels of vitamin A can lead to toxicity.
How can I prevent vitamin A deficiency?
The best way to prevent vitamin A deficiency is to eat a healthy diet that includes foods that contain vitamin A. Vitamin A can be found naturally in:
- Green vegetables, such as leafy greens and broccoli.
- Orange and yellow vegetables, such as carrots, pumpkin, sweet potatoes and squash.
- Orange and yellow fruits, such as oranges, mangos, cantaloupe and papayas.
- Dairy products.
- Liver, beef and chicken.
- Certain types of fish, such as salmon.
- Cereals, rice potatoes, wheat and soybeans fortified with vitamin A.
If necessary, you can also take a vitamin A supplement.
Outlook / Prognosis
What can I expect if I have vitamin A deficiency?
If you increase your vitamin A intake, some of the effects of vitamin A deficiency should start to reverse. Night blindness and dry eyes should improve. However, corneal ulcers can’t be corrected.
It’s important to eat enough foods that contain vitamin A.
In addition, take a dietary supplement that contains vitamin A. If you don’t get enough vitamin A, complications such as vision loss will be long-term.
A note from Cleveland Clinic
Vitamin A is a vitamin that plays an important role in your vision. While vitamin A deficiency is rare in the United States, it can cause severe complications such as vision loss, skin issues and immune system problems. It’s important to eat a diet that includes foods that have vitamin A, such as meat, dairy, dark leafy greens, and yellow or orange fruits and vegetables. In addition, you can get vitamin A from a dietary supplement if needed.
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