Vitamin A deficiency

Vitamin A deficiency is a serious health concern that arises when the body does not receive adequate amounts of vitamin A, an essential nutrient required for proper vision, metabolism, cell development, and immune system function. The human body is unable to synthesise vitamin A on its own, making it necessary to obtain this vital nutrient through a balanced diet or supplementation. Vitamin A deficiency can stem from a diet lacking in vitamin A-rich foods or from underlying health conditions that hinder the absorption or storage of this nutrient in the liver.

What is Vitamin A Deficiency?

Vitamin A deficiency, also known as hypovitaminosis A, is a condition characterised by inadequate levels of vitamin A in the body. This fat-soluble vitamin is essential for various physiological processes, including visual function, immune system regulation, and cellular growth and differentiation. Without proper diagnosis and treatment, vitamin A deficiency can lead to a range of serious health consequences.

The symptoms of vitamin A deficiency can manifest in various ways, depending on the severity and duration of the deficiency. Some people may experience only mild symptoms, while others may develop severe and potentially life-threatening complications. The following are a few common visible vitamin A deficiency symptoms:

1. Night Blindness

One of the earliest signs is night blindness, a condition caused by a disorder of the retina that makes it difficult to see in low-light conditions. This occurs because vitamin A is essential for the production of rhodopsin, a pigment necessary for night vision.

2. Xerophthalmia

As the deficiency progresses, the eyes may become dry and thick, leading to a condition called xerophthalmia, which can potentially damage the cornea and retina.

3. Bitot's Spots

Bitot's spots are distinctive lesions on the eye's conjunctiva and appear as triangular, grey, or white patches, often described as having a frothy or foamy surface.

4. Keratomalacia

Keratomalacia is a serious eye condition characterised by the softening and clouding of the cornea. This condition often begins with xerophthalmia, which involves extreme dryness of the eyes and conjunctiva, and can lead to significant ocular complications if not treated promptly.

5. Corneal Ulcers

Corneal ulcers, also known as keratitis, are medical conditions characterised by open sores on the cornea, the transparent part of the eye. These ulcers can lead to vision loss if not treated promptly.

6. Dry and Scaly Skin

Vitamin A deficiency can also cause the skin to become dry, itchy, and scaly, as this nutrient plays a crucial role in maintaining healthy skin.

7. Disease Susceptibility

Vitamin A deficiency can also weaken the immune system, making individuals more susceptible to infections, especially infants and children.

8. Poor Growth and Development

Children with vitamin A deficiency may experience stunted growth and development.

Vitamin A deficiency can stem from various factors, chiefly related to insufficient dietary intake, compromised absorption, or medical conditions affecting vitamin A storage and use in the body. Primary causes encompass:

1. Dietary Deficiencies

Prolonged consumption of a diet lacking in vitamin A-rich foods such as animal liver, eggs, fortified dairy products, and carotenoid-rich fruits and vegetables (like orange and yellow fruits and dark green leafy vegetables) is a common cause of deficiency.

2. Malabsorption Disorders

Health issues that impair the intestines' ability to absorb fats, including chronic diarrhoea, coeliac disease, cystic fibrosis, pancreatic insufficiency, and bile duct disorders, can hinder vitamin A absorption.

3. Liver Diseases

Hepatic conditions such as cirrhosis can interfere with the storage and metabolism of vitamin A, potentially leading to a deficiency.

4. Protein-energy Malnutrition

Severe deficiencies in protein and calories can hamper the body's ability to store and utilise vitamin A effectively.

5. Surgical Procedures

Operations involving the intestines or pancreas may also negatively impact vitamin A absorption.

Recognising the multifaceted nature of vitamin A deficiency causes is crucial for accurate diagnosis and appropriate treatment.

Certain populations face a heightened risk of developing vitamin A deficiency due to geographical, age-related, and health factors.

Who's at Risk?

People falling under the following criteria are at risk of developing vitamin A deficiency:

• Geographical Regions: Individuals living in developing countries, particularly in Africa and Southeast Asia, where diets often lack sufficient vitamin A-rich foods, are particularly vulnerable.

• Age Groups: Children under five years old in developing countries face a significant risk of vitamin A deficiency.

• Health Conditions:

  • Those with gastrointestinal diseases like coeliac disease, liver cirrhosis, pancreatic insufficiency, bile duct disorders, and giardiasis.

  • Pregnant and breastfeeding women due to increased daily requirements.

  • Individuals with chronic infections, especially measles, which can rapidly deplete vitamin A levels.

  • People who have undergone abdominal surgeries, including small bowel bypass and bariatric procedures.

Understanding these risk factors is essential for targeted prevention and early intervention strategies to combat vitamin A deficiency.

Left untreated, vitamin A deficiency can lead to a range of serious health complications affecting vision, skin, immune function, and overall well-being.

Vision Problems

One of the earliest signs of vitamin A deficiency is changes in your vision, such as:

• Night Blindness: Difficulty seeing in low light conditions, potentially progressing to complete blindness at night

• Xerophthalmia: Dryness and thickening of the conjunctiva and cornea, which may result in blindness if left untreated

• Keratomalacia: Drying and clouding of the cornea, causing vision loss

• Bitot's Spots: Formation of foamy deposits in the whites of the eyes

• Corneal Ulcers: Open sores on the cornea, which can ultimately result in blindness

Skin Issues

Skin issues arising due to vitamin A deficiency include:

• Dry, rough, and scaly skin and mucous membranes

• Follicular Hyperkeratosis: Excessive keratin buildup around hair follicles, leading to skin thickening and a "goose flesh" appearance

Compromised Immune Function

Vitamin A deficiency can also lead to impaired immune function and the risk of contracting secondary infections.

• Increased susceptibility to infections, particularly measles and diarrhoeal diseases

• Delayed wound healing and impaired recovery from illnesses

Other Complications

Apart from vision problems, skin issues, and an impaired immune system, hypovitaminosis A is also responsible for:

• Impaired growth and development in children

• Increased risk of anaemia

• Potential reproductive issues, including birth defects

Promptly addressing vitamin A deficiency through proper diagnosis, treatment, and preventive measures is crucial to avoid these potentially life-altering complications.

Preventing vitamin A deficiency is crucial, especially in regions where the deficiency is prevalent. Dietary modifications, supplementation, and public health measures are key strategies to prevent vitamin A deficiency.

Dietary Modifications

Consuming a healthy diet rich in vitamin A is essential. Preformed vitamin A (retinol) can be found in animal products such as beef, poultry, fish, liver, and eggs, as well as in fortified cereals and dairy products. Plant sources of vitamin A include carotenoids, which are found in yellow, orange, and red fruits and vegetables like carrots, green leafy vegetables, and deep- or bright-coloured fruits.

Supplementation

In developing countries, periodic administration of high-dose vitamin A supplements is effective. The recommended dosage, however, varies by age group and from country to country. Breastfeeding, especially in the first 4–6 months, provides essential vitamin A to infants, and maternal supplementation can enhance the vitamin A content in breast milk.

Public Health Measures

Public health measures, such as fortification of foods like cereals and dairy products with vitamin A and educational campaigns about the importance of vitamin A-rich foods and supplements, can help prevent deficiency at a population level.

Diagnosing vitamin A deficiency involves a combination of clinical assessment, medical history, and laboratory tests.

• Clinical symptoms suggestive of vitamin A deficiency include night blindness (nyctalopia), dry corneas, keratomalacia, dry, itchy, and scaly skin, and impaired immune function. A history of impaired dark adaptation and the presence of xerophthalmia (dry eyes) are key clinical indicators of vitamin A deficiency.

• The doctor will review the patient's medical history, including any conditions that might affect vitamin A absorption, such as liver disorders, intestinal diseases, and chronic infections.

• Laboratory tests for vitamin A deficiency diagnosis include electroretinography to measure the photoreceptor response in the retina and serum retinol concentration tests. Other tests, such as the relative dose-response test and the modified relative dose-response test, can help assess hepatic vitamin A stores.

Prompt diagnosis is essential for initiating appropriate vitamin A deficiency treatment and preventing severe complications.

As already discussed, the management of vitamin A deficiency involves a combination of dietary modifications, supplementation, and treatment of associated complications. The primary goal is to replenish vitamin A stores and prevent further deficiency.

Dietary Modifications

This includes increasing the intake of vitamin A-rich foods, such as liver, eggs, dairy products, and fortified foods. Encouraging the consumption of carotenoid-rich fruits and vegetables, such as carrots, sweet potatoes, and spinach, can also help boost vitamin A levels.

Supplementation

As mentioned before, vitamin A supplementation is a crucial component of treatment, especially in severe deficiency cases. The World Health Organisation (WHO) recommends high-dose vitamin A supplementation for children aged 6–59 months in areas with a high prevalence of vitamin A deficiency.

Medication for Vitamin A Deficiency

Vitamin A deficiency medication includes high doses of vitamin A supplements, which can be administered in various forms, such as capsules, gel capsules, or liquid drops.

The salts commonly used in vitamin A supplements include:

• Retinol, the active form of vitamin A

• Retinyl acetate, a form used in supplements and fortified foods

• Retinyl palmitate, another form used in supplements and cosmetics

• Beta-carotene, a precursor to vitamin A, which can be converted into retinol in the body

It is, however, important to note that during pregnancy and breastfeeding, prophylactic or therapeutic doses should not exceed 10,000 IU per day to avoid potential damage to the foetus or infant. Additionally, patients should be cautious about interactions with other medications such as tetracyclines, antacids, anticoagulants, cholesterol-lowering medications, and certain antibiotics when managing vitamin A deficiency. It is always recommended to consult your doctor before starting any supplements.

• Vitamin A deficiency is a serious condition that can lead to various health issues, including xerophthalmia, night blindness, increased susceptibility to infections, and even death in severe cases.

• The main causes of vitamin A deficiency include inadequate dietary intake of vitamin A-rich foods, malabsorption disorders, and certain medical conditions that interfere with vitamin A metabolism.

• Symptoms of vitamin A deficiency can vary depending on the severity and duration of the deficiency, with the most common being night blindness, dry eyes, and increased susceptibility to infections.

• Diagnosis of vitamin A deficiency typically involves a combination of clinical assessment, dietary history, and laboratory tests, such as serum retinol levels.

• Treatment involves high doses of vitamin A supplements, with the dosage varying by age and special considerations for pregnant and breastfeeding women.

• Vitamin A deficiency prevention strategies include ensuring adequate intake of vitamin A-rich foods, fortification of staple foods with vitamin A, and supplementation programmes targeting high-risk populations.