Vitamin A deficiency

Vitamin A deficiency can lead to the following symptoms:

• Impaired sensitivity of the eye to light
• Impaired vision in the dark
• Vision loss
• Blindness
• Dryness in the eyes, skin, nails, and lips
• Growth retardation
• Thickened tongue
• Fatigue
• Repeated occurrence of infections
• Inflammation of the eyelids and surrounding areas
• Urinary tract infection

Severe Vitamin A deficiency can cause xerophthalmia, which can lead to the following symptoms:

• Night blindness: Impaired sensitivity of the eye to light
• Conjunctival xerosis: Dull, dry, thick, wrinkled appearance of the conjunctiva (the thin, clear membrane that protects the eye)
• Bitot spots: Whitish, foamy, opaque deposits on the conjunctiva
• Corneal xerosis: Dull, dry, and hazy appearance of the cornea (the transparent front part of the eye)
• Keratomalacia: Presence of ulcers and softening of the cornea
• Corneal scars: Scarring of the cornea
• Xerophthalmic fundus: Structural changes in the back surface of the eye

Vitamin A is a fat-soluble vitamin that is required for:

• Normal vision
• Proper functioning of the immune system
• Reproduction
• Growth and development

The major function of Vitamin A is the maintenance of normal vision. Eyes need certain pigments to see the full spectrum of light. The synthesis of these pigments is halted by a deficiency of Vitamin A. Severe Vitamin A deficiency also leads to improper moisturization of the eye.

What can lead to Vitamin A deficiency?

1. Inadequate dietary intake of Vitamin A
   Low intake of dietary sources of Vitamin A can be attributed to:
   • Insufficient dietary intake
   • Long-term alcoholism
   • Highly selective eating
   • Difficulty in swallowing
   • Mental illness
2. Impaired absorption of Vitamin A
   The absorption of Vitamin A primarily takes place in the upper part of the small intestine. The presence of any diseases affecting the intestine can cause insufficient absorption of Vitamin A and lead to its deficiency.
3. Reduced storage of Vitamin A
   The reduced storage of Vitamin A can also be a cause of its deficiency:
   • Liver diseases
   • Cystic fibrosis (an inherited disorder that mainly affects the lungs and digestive system)

Risk Factors For Vitamin A Deficiency

The following factors increase the risk of Vitamin A deficiency:

1. Age
   Pre-school children are more prone to develop a deficiency of Vitamin A. Studies suggest that the highest prevalence of Vitamin A deficiency is seen in children between 36 to 47 months of age.
2. Malnutrition or Severely Restricted Diets
   Malnourished individuals and those who follow a severely restricted diet can have multiple vitamin deficiencies, including Vitamin A deficiency.
3. Zinc Deficiency
   Vitamin A is transported throughout the body with the help of zinc. A deficiency of zinc makes the individual more prone to develop Vitamin A deficiency as well.
4. Pregnancy
   Pregnant women are at higher risk of developing Vitamin A deficiency due to increased demand.
5. Bariatric Surgery
   Bariatric surgery, a type of weight loss surgery, increases the risk of developing a deficiency of Vitamin A due to the malabsorption of certain vitamins and minerals.
6. Certain Medical Conditions
   Medical conditions that impair the ability of the intestine to absorb fat, along with some infections, make an individual more likely to develop Vitamin A deficiency. Such conditions include:

• Chronic diarrhea
• Celiac disease
• Cystic fibrosis
• Blockage of bile duct
• Measles

The diagnosis is made through medical history and physical examination, and confirmed by response to vitamin A supplementation. The various tests used to determine Vitamin A deficiency include:

I. Blood Tests

• Serum Retinol: Retinol is the circulating form of Vitamin A. The test measures the amount of retinol in the blood. Blood concentrations of retinol do not reflect exact amounts of Vitamin A due to the maintenance of circulating retinol levels by liver stores. However, this test is used to assess subclinical deficiency of Vitamin A. A level less than 0.70 μmol/L indicates subclinical vitamin A deficiency.
• Serum Retinol-Binding Protein Study: Retinol binding protein is a protein through which retinol is transported in the body. This test measures the quantity of this protein using a fluorometer.
• Zinc Level: Estimation of zinc is useful since its deficiency is also associated with Vitamin A deficiency.
• Iron: Individuals with confirmed Vitamin A deficiency are also suggested to detect the level of iron, as iron deficiency can affect the metabolism of vitamin A.
• Complete Blood Cell Count (CBC): A CBC is recommended if there is a possibility of anemia, infection, or sepsis.
• Electrolyte Level: An electrolyte evaluation and liver function studies should be performed to assess nutritional and volume status.

II. Imaging Tests

• X-rays: Radiography of bones is mostly recommended in children for the evaluation of their growth as a result of Vitamin A deficiency.
• Dark-Adaptation Threshold (DAT): This vision test measures the adjustment of the eye after exposure to darkness.

The deficiency of Vitamin A can be prevented by the following measures:

1. Encouraging breastfeeding
   Newborns are generally born with very low levels of Vitamin A. Breast milk serves as an excellent source of Vitamin A, especially during the initial six months of life. Children who receive exclusively breast milk for the first six months have a lower risk of developing Vitamin A deficiency later in life. Postpartum women should consume Vitamin A-rich foods or supplements if needed, as this enhances the Vitamin A content in breast milk.
2. Consuming an adequate amount of Vitamin A
   The best way to prevent Vitamin A deficiency is to consume an adequate amount of Vitamin A through a healthy balanced diet rich in sources such as carrots, milk, fish, eggs, green vegetables, yams, and sweet potatoes. Individuals on restrictive diets or those facing challenges in obtaining sufficient Vitamin A should consider taking the recommended dose of Vitamin A supplements. Adequate intake during pregnancy and lactation is crucial for building stores in the liver.
3. Maintaining environmental sanitation
   The risk of Vitamin A deficiency increases with certain diseases such as respiratory tract infections, tuberculosis, diarrhea, and worm infestations. Proper sanitation of the living environment helps reduce the prevalence of these diseases.
4. Ensuring proper vaccination
   Certain vaccine-preventable diseases, such as measles, can precipitate Vitamin A deficiency. Immunization plays a key role in eliminating these factors and may help in preventing this deficiency.

The primary treatment approach includes the consumption of Vitamin A-rich foods, such as:

• Liver
• Beef
• Chicken
• Eggs
• Fortified milk
• Carrots
• Mangoes
• Sweet potatoes
• Leafy green vegetables

In severe cases, the following approaches are considered:

Vitamin A Supplementation

This includes the intake of Vitamin A supplements, recommended for individuals with serum retinol concentrations less than 20 micrograms/dL. The dosing of Vitamin A is based on the severity of symptoms.

Intramuscular injections of Vitamin A are recommended for individuals experiencing malabsorption.

The recommended levels of Vitamin A according to the age of the patient are:

• Children aged 3 years or younger: 600 mcg (2000 IU)
• Children aged 4-8 years: 900 mcg (3000 IU)
• Children aged 9-13 years: 1700 mcg (5665 IU)
• Children aged 14-18 years: 2800 mcg (9335 IU)
• All adults: 3000 mcg (10,000 IU)

Zinc Supplementation

In most cases, zinc supplements are also given along with Vitamin A supplements.

Vitamin A can be easily corrected through the right diet and supplementation. However, severe Vitamin A deficiency can lead to:

• Increased susceptibility to infections
• Impaired immune function
• Difficulty in conceiving
• Infertility
• Permanent vision loss
• Blindness

1. Dietary Modifications

It is essential to incorporate rich sources of Vitamin A into the diet. Foods high in Vitamin A include:

• Fruits: Mango, papaya, and tomatoes
• Tuber Crops: Sweet potato
• Leafy Vegetables: Coriander, spinach, curry leaves, mint, and radish leaves
• Non-Vegetarian Sources: Eggs, chicken, and beef
• Dairy Products: Milk and cheese

Consume at least 5 servings of any of these foods daily to maintain adequate levels of Vitamin A.

2. Look for Fortified Foods

The market offers a variety of fortified foods, such as breakfast cereals, pastries, breads, crackers, and cereal grain bars. Including these foods in your diet can help maintain good levels of Vitamin A.

3. Be Aware of Toxicity

Excessive consumption of Vitamin A over a short period can lead to toxicity. It is advisable to take supplements according to the recommended dosage. Signs and symptoms of Vitamin A toxicity include:

• Skin irritation
• Drowsiness
• Irritability
• Abdominal pain
• Nausea
• Vomiting