Vitamin A deficiency: Causes, Risk Factors, Symptoms, Treatment

Vitamin A deficiency

Vitamin A performs the functions of aiding vision, tissue strength and immunity, and growth. The chemical name retinol was given to vitamin A because of its major function in the retina of the eye. The aldehyde form, retinal, is part of a light-sensitive pigment in retinal cells called rhodopsin, which is commonly known as visual purple. Rhodopsin enables the eye to adjust to different amounts of available light. A mild vitamin A deficiency may cause night blindness, slow adaptation to darkness, or glare blindness. Vitamin-A-related compounds (i.e., the carotenoids lutein and zeaxanthin) are specifically associated with the prevention of age-related macular degeneration. 

Vitamin A Deficiency

If you suspect you or someone else is experiencing Vitamin A deficiency, it is crucial to seek immediate medical attention by calling emergency services or consult with a Nutritionist.


Several factors can cause this deficiency:

Inadequate Diet: Not consuming enough foods rich in vitamin A is a primary cause. This deficiency is more common in regions where diets lack sources of vitamin A, such as fruits, vegetables, and animal products.

Malabsorption Issues: Some health conditions, like celiac disease, cystic fibrosis, and certain gastrointestinal disorders, can impair the body's ability to absorb vitamin A from the diet, leading to deficiency.

Limited Fat Absorption: Since vitamin A is fat-soluble, conditions that affect fat absorption, such as pancreatic disorders or bile duct obstruction, can hinder the absorption of vitamin A.

Poor Liver Function: Vitamin A is stored in the liver. Liver diseases, like cirrhosis or hepatitis, can disrupt the storage and conversion of vitamin A into its active forms, contributing to deficiency.

Alcoholism: Chronic alcohol consumption can interfere with the body's ability to store and utilize vitamin A properly, leading to deficiency.

Infancy and Early Childhood: Infants and young children are particularly vulnerable to vitamin A deficiency due to inadequate intake or an immature digestive system.

Vegetarian/Vegan Diets: Vitamin A is predominantly found in animal-derived products, such as liver, dairy, and fish oil. Individuals following strict vegetarian or vegan diets might have a higher risk of vitamin A deficiency unless they consume adequate plant-based sources of provitamin A carotenoids found in colorful fruits and vegetables.

Poverty and Limited Access to Nutritious Foods: In some cases, socioeconomic factors contribute to poor dietary diversity and limited access to foods rich in vitamin A, leading to deficiency in certain populations.

Risk Factors

Several risk factors contribute to the development of vitamin A deficiency:

Poor Diet: Inadequate consumption of foods rich in vitamin A, such as fruits, vegetables, dairy products, eggs, and liver, can lead to deficiency.

Limited Access to Nutrient-Rich Foods: In regions with food scarcity, limited access to a diverse diet containing vitamin A-rich foods can increase the risk of deficiency.

Malabsorption Issues: Certain medical conditions, such as celiac disease, Crohn's disease, pancreatic disorders, or surgical removal of the part of the intestine, can impair the absorption of vitamin A from the diet.

Alcoholism: Chronic alcohol consumption can interfere with the absorption and utilization of vitamin A in the body.

Infancy and Early Childhood: Infants who are exclusively breastfed by mothers with insufficient vitamin A intake or those not receiving adequate complementary foods rich in vitamin A are at risk of deficiency.

Underlying Health Conditions: Conditions that affect the liver, such as liver diseases or disorders, may impair the storage and conversion of vitamin A in the body.

Poverty and Limited Resources: Socioeconomic factors, including poverty and limited access to healthcare and nutritional education, can contribute to a lack of vitamin A-rich foods in the diet.

Prolonged Diarrhea: Chronic diarrhea can lead to increased excretion of nutrients, including vitamin A, leading to deficiencies, especially in children.

Parasitic Infections: Infections like intestinal parasites can contribute to malabsorption issues and interfere with the body's ability to absorb and utilize vitamin A.

Suboptimal Breastfeeding Practices: Inadequate breastfeeding practices, including premature cessation of breastfeeding or lack of proper lactation support, can contribute to vitamin A deficiency in infants and young children.


Toxicity Symptoms The condition created by excessive vitamin A intake is called hypervitaminosis A. Symptoms include bone pain, dry skin, loss of hair, fatigue, and anorexia. Excessive vitamin A intake may cause liver injury with portal hypertension, which is elevated blood pressure in the portal vein, and ascites, which is fluid accumulation in the abdominal cavity. Because of the potential for toxicity, the UL of retinol for adults has been set at 3000 mcg/ day.2 Although vitamin A deficiency is more common worldwide than toxicity, children in the United States may consume excess vitamin A from fortified foods alone, without added vitamin A from dietary supplements.4 Toxicity symptoms usually result from the overconsumption of preformed vitamin A rather than of carotenoids. The absorption of dietary carotenoids is dose-dependent at high intake levels. However, the prolonged excessive intake of foods that are high in β-carotene will cause a harmless orange skin tint that disappears when the excessive intakes are discontinued. Alternatively, β-carotene supplements can reach concentrations in the body that promote oxidative damage, cell division, and the destruction of other forms of vitamin A Food Forms and Units of Measure Vitamin A occurs in two forms, as follows: 1. Preformed vitamin A or retinol, which is the active vitamin A found in foods that are derived from animal products. 2. Provitamin A or β-carotene, which is a pigment in yellow, orange, and deep green fruits or vegetables that the human body can convert to retinol. Carotenoids are a family of compounds that are similar in structure; β-carotene and lutein are the most common in foods (Box 7-1). In the typical American diet, a significant amount of vitamin A is in the provitamin A form (i.e., β-carotene). To account for all food forms, individual carotenoids and preformed vitamin A are measured, and the amounts are converted to retinol equivalents. For the body to make 1 mcg of retinol, 12 mcg of dietary β-carotene, 2 mcg of supplemental β-carotene, or 24 mcg of either of the carotenoids (α-carotene or β-cryptoxanthin) are necessary. An older measure that is sometimes used to quantify vitamin A is the International Unit (IU). One IU of vitamin A equals 0.3 mcg of retinol or 0.6 mcg of β-carotene.

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Blood concentrations of retinol in plasma or serum are used to assess subclinical vitamin A deficiency. A plasma or serum retinol concentration <0>


When it comes to treating vitamin A deficiency, there are several effective approaches that can help individuals restore their vitamin A levels and improve their overall health. One of the most common treatments for vitamin A deficiency is through dietary changes. Including foods rich in vitamin A, such as liver, eggs, dairy products, and colorful fruits and vegetables like carrots, sweet potatoes, and spinach can significantly boost vitamin A levels in the body. In some cases where dietary changes alone may not be sufficient, healthcare professionals may recommend oral supplements of vitamin A. These supplements are available in various forms like capsules or tablets and can be taken under medical supervision to ensure proper dosage. For severe cases of vitamin A deficiency or when an individual is unable to absorb nutrients adequately through oral supplementation, injections or intravenous administration of vitamin A may be required. This method allows for direct delivery of the nutrient into the bloodstream for faster absorption and results. It's important to note that treatment plans should always be personalized based on an individual's specific needs and medical history. Consulting with a healthcare professional is crucial to determine the most appropriate treatment approach for managing vitamin A deficiency effectively.

Preventive Measures

Diet should contain Fish liver oils, liver, egg yolks, butter, and cream are sources of preformed natural vitamin A. Preformed vitamin A occurs naturally in milk fat. Low-fat and nonfat milks and margarine are significant sources of vitamin A, because they are fortified. Some good sources of β-carotene are dark green leafy vegetables such as Swiss chard, turnip greens, kale, and spinach as well as dark orange vegetables and fruits such as carrots, sweet potatoes or yams, pumpkins, mangoes, and apricots. β-Carotene and preformed vitamin A require emulsification by bile salts to be absorbed by the intestine. Preformed vitamin A is efficiently absorbed at a rate of 70% to 90%, whereas provitamin A (carotenoids) are less bioavailable at an absorption rate of 20% to 50%. Inside the intestinal cells, both forms are incorporated into chylomicrons with fat, and the chylomicrons pass through the lymphatic system and into the bloodstream.

Do's & Don’t's

Do's Don't
Consume Vitamin A-rich foods such as carrots, sweet potatoes, spinach, kale, liver, eggs, and dairy products. Avoid excessive consumption of alcohol, as it can interfere with Vitamin A absorption.
Incorporate fortified foods like fortified cereals or fortified dairy products into your diet. Don't rely solely on supplements without consulting a healthcare professional, as excessive Vitamin A intake can be harmful.
Seek medical advice and guidance if you suspect a Vitamin A deficiency or are at risk due to certain health conditions or dietary restrictions. Avoid diets lacking in diversity and consisting solely of processed foods, which may lack essential nutrients including Vitamin A.
Follow a balanced diet with a variety of fruits, vegetables, and protein sources to ensure adequate intake of Vitamin A and other essential nutrients. Don't cook Vitamin A-rich foods excessively, as it can reduce their nutrient content. Opt for steaming, roasting, or consuming raw when appropriate.
Consider using cooking methods that preserve the Vitamin A content in foods, such as steaming or lightly sautéing vegetables. Don't ignore the symptoms of Vitamin A deficiency, such as night blindness, dry skin, or weakened immune function. Consult a healthcare professional for proper diagnosis and treatment.

If you suspect you or someone else is experiencing Vitamin A deficiency, it is crucial to seek immediate medical attention by calling emergency services or consult with a Nutritionist.

Frequently Asked Questions
Vitamin A is a fat-soluble vitamin that plays a crucial role in various bodily functions, including vision, immune system support, and skin health.
Vitamin A is essential for maintaining healthy skin, vision, and immune system function. It also plays a role in the proper functioning of organs like the heart, lungs, and kidneys.
Vitamin A deficiency can result from inadequate intake of foods rich in vitamin A, malabsorption issues, or certain health conditions that affect the body's ability to use this vitamin.
Symptoms may include night blindness, dry skin, impaired immune function, and in severe cases, it can lead to more serious conditions like xerophthalmia (a condition that can cause blindness).
Foods rich in Vitamin A include liver, sweet potatoes, carrots, spinach, kale, eggs, and dairy products.
Individuals with poor dietary habits, limited access to a variety of foods, infants and young children, pregnant and lactating women, and those with certain medical conditions that affect nutrient absorption may be at a higher risk.
Yes, ensuring a balanced diet that includes foods rich in Vitamin A is key to preventing deficiency. In some cases, supplements may be recommended, especially for at-risk populations.
Diagnosis is often based on clinical symptoms, dietary history, and blood tests measuring serum retinol levels.
Yes, it can be treated through dietary changes and, in some cases, supplementation. However, it's crucial to seek medical advice for appropriate diagnosis and treatment.
Yes, excessive intake of Vitamin A, either through diet or supplements, can lead to toxicity symptoms, which may include nausea, dizziness, and, in severe cases, organ damage.
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