What Is Vitamin A Deficiency?

Vitamin A is a fat-soluble vitamin that is naturally present in many of the foods we eat. It’s important for a strong immune system, healthy vision, and reproduction. Vitamin A also helps the lungs, heart, and kidneys to function properly.

The two types of vitamin A found in our foods are preformed vitamin A and provitamin A:

  • Preformed vitamin A (retinol and retinyl esters) is found in foods from animal sources, including meat and dairy.
  • Provitamin A carotenoids are found in plant-based foods like fruits and vegetables. The most common form of provitamin A present in foods and supplements is beta-carotene.

Vitamin A deficiency is unusual in developed countries. Globally, however, it is one of the most common nutrient deficiencies. Pregnant people and children are at the highest risk of a vitamin A deficiency.

This article will discuss the signs, causes, complications, and treatment of vitamin A deficiency.

Vitamin A deficiency night blindness

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What Is Vitamin A Deficiency?

Vitamin A deficiency typically occurs when a person does not consume enough foods rich in vitamin A to meet their body's required needs.

Although it is rare in developed countries like the United States, it remains very common in low-income countries where residents lack access to food sources of provitamin A carotenoids and preformed vitamin A.

Signs and Symptoms

Depending on the severity of the deficiency, signs and symptoms may vary. The most common symptom of vitamin A deficiency in pregnant women and children is xeropthalmia.

Xeropthalmia is a progressive eye disease that typically starts with dry eyes. It often progresses to night blindness or difficulty seeing in low light. If the deficiency is left untreated, it can lead to total vision loss.

A person with a vitamin A deficiency may also develop Bitot's spots. These appear as subtle "foamy" eye lesions with a triangular shape.

Studies also show a vitamin A deficiency is linked to emphysema and other respiratory diseases, including childhood asthma. Therefore, supplementation of vitamin A is recommended in high-risk populations to treat and prevent lung diseases.

Other symptoms of a vitamin A deficiency include:

  • Fatigue
  • Increased infections
  • Infertility
  • Dry skin and hair

Causes and Risk Factors

Pregnant and breastfeeding people, infants, and young children in developing countries are at the highest risk of vitamin A deficiency. An estimated 50% of pre-school-aged kids and pregnant mothers worldwide are at risk.

In fact, vitamin A deficiency is the number one preventable cause of childhood blindness globally.

Additionally, preterm infants who do not have adequate liver stores of vitamin A are likely to experience a deficiency throughout the first year of their lives.

Conditions and procedures that interfere with the body's ability to absorb fat include:

  • Cirrhosis (excessive scarring of the liver)
  • Cystic fibrosis (a genetic condition that causes mucus production in organs such as the lungs, colon, and pancreas)
  • Chronic diarrhea (diarrhea that lasts longer than a few weeks)
  • Bariatric surgery (weight loss surgery)
  • Crohn's disease (a chronic inflammatory bowel disease that can affect the gastrointestinal tract)

Complications

Over time, vitamin A deficiency can lead to complications if left untreated.

In addition to vision loss, children who are deficient in vitamin A are more at risk of stunting, or delayed growth and development.

Vitamin A deficiency reduces the ability to fight off illness and infection. This may lead to an increase in mortality in children with common childhood infections.

Vitamin A deficiency is also associated with pregnancy deaths and other negative consequences during pregnancy and breastfeeding.

Diagnosis and Evaluation

Vitamin A deficiency is more common if you have an underlying condition that puts you at a higher risk for developing a deficiency in fat-soluble vitamins. If that's the case, you should have regular screenings to ensure you have no nutrient deficiencies.

If you are experiencing any symptoms associated with vitamin A deficiency, such as nighttime blindness or Bitot's spots, be sure to contact your healthcare provider as soon as possible for an evaluation.

Diagnosing vitamin A deficiency begins with a visit to your healthcare provider. They will complete a comprehensive exam and check retinol levels in your blood.

What Are Normal Retinol Levels?

Normal values range from 20 to 60 micrograms per deciliter (mcg/dL).

A plasma retinol level of less than 20 micrograms per deciliter reflects a vitamin A deficiency.

Treatment and Prevention

The best way to prevent a vitamin A deficiency is to eat a nutrient-rich, well-balanced diet. The Recommended Dietary Allowances (RDA) for Vitamin A are listed in micrograms of retinol activity equivalents (RAE), which considers the different absorption rates of both forms of vitamin A.

The RDA for adults over the age of 19 is:

  • 900 micrograms RAE for males
  • 700 micrograms RAE for females
  • 770 micrograms RAE during pregnancy
  • 1,300 micrograms RAE during lactation

If you're diagnosed with vitamin A deficiency, your healthcare provider may ask you to change your diet to add more vitamin A-rich foods. They may prescribe an oral supplement to increase the levels of vitamin A in your blood until the deficiency is corrected.

Vitamin A supplementation can interact with certain medications. Always speak with your healthcare provider or pharmacist about any over-the-counter medicines or dietary supplements you are taking to ensure safety.

What Foods Contain Vitamin A?

Vitamin A is found in many of the foods that we eat. It's also added to some foods like cereal, juice, and milk. To ensure you meet the RDA for vitamin A, it's important to consume a balanced, healthy diet.

Foods Rich in Vitamin A

  • Leafy greens like spinach, kale, and broccoli
  • Orange and yellow vegetables like sweet potatoes, carrots, and squash
  • Cantaloupe
  • Mango
  • Apricots
  • Dairy products
  • Beef liver and organ meats
  • Salmon
  • Eggs
  • Tomatoes

Summary

While vitamin A deficiencies are rare in developed countries like the United States, they still exist. You may have trouble absorbing nutrients because of an underlying health issue, or you may experience symptoms associated with vitamin A deficiency.

If so, then it is important to call your healthcare provider for a comprehensive evaluation and blood test.

For most people, eating an overall healthy diet will ensure you meet your daily vitamin A needs to prevent a deficiency. Be sure your diet is rich in fruits, vegetables, whole grains, lean protein, and healthy fats.

Others, however, may require oral vitamin A supplementation until levels return to normal.

Frequently Asked Questions

  • What are the early signs of vitamin A deficiency?

    Early signs of vitamin A deficiency include difficulty seeing at night, dry eyes, and dry skin.

  • Is it okay to take vitamin A every day?

    Taking too much vitamin A in large doses every day can lead to harmful side effects. It's best to speak with your healthcare provider to discuss how long you'll need to continue taking your vitamin A supplementation.

  • How does vitamin A help the immune system?

    Vitamin A is necessary for the development of the immune system. It also plays a large role in cellular immune system responses and fighting inflammation.

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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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