Vitamin A Deficiency Symptoms

Vitamin A is a fat soluble vitamin that is found in vegetables, fruits and animal food products. Vitamin A is classified into three categories, depending on its source: Retinol (preformed vitamin A), Beta-carotene (provitamin A) and carotenoids. Retinol is called preformed vitamin A because it is the most active form of the vitamin. It is found in animal sources of food like liver, eggs, sea food and cheese. Provitamin A or beta-carotene is a precursor of vitamin A, obtained from plant sources like sweet potato, carrots, oranges, tomato, spinach, etc. This beta-carotene is converted into retinol in the body. Carotenoids, the largest category of the three, comprises multiple conjugated double bonds, and exists in a Fatty Acyl Ester form or free alcohol form. Retinol is present in a predominant form in the body.

Vitamin A is an essential nutrient in the body due to the various functions it plays. Retinol occurs in the rods (the light sensitive part of the eye) of the eye, which is responsible for allowing night vision or vision in dim lit surroundings. Retinol is responsible for the conduction of light signals to the nerve cells of the retina, making it very important for vision. Besides this, it is also responsible for bone growth, immune response, eye surface lining maintenance, epithelial cell growth, and so on. Vitamin A is also available in another form in the body called retinoic acid. This retinoic acid is required for the development of skin cells, the lining of the intestines and lungs. A fertilized egg requires vitamin A for its development into a fetus, which is why vitamin A is crucial for embryonic development. Moreover, vitamin A is needed for the regulation of adult genes, cell growth, division and differentiation.

Vitamin A Deficiency

The Food and Drug Administration (FDA) has recommended a daily allowance of 5000 IU of vitamin A. Vitamin A deficiency is a common phenomenon occurring in underdeveloped and developing countries, however, rarely seen in developed countries. Moreover, when vitamin A deficiency occurs in people from the developed countries, it is seen in alcoholics. In the US, this deficiency is seen in the poor, malnourished, chronically sick populations and elderly. The deficiency can be conduced by inadequate intake, liver disorders and fat malabsorption.

Diseases such as cystic fibrosis, cholestasis, celiac disease affect the body's ability to absorb fat. Chronic consumption of diets deficient in vitamin A and beta-carotene leads to vitamin A deficiency. In the early 1900s, infants in Denmark were observed to be stricken by this deficiency. What happened was that milk fat was converted into butter for export purposes, thereby leaving only skimmed milk for infant feeding, which led to the deficiency.

Prolonged dietary deprivation, as observed in Southern and Eastern Asia, wherein polished rice is the staple food, which is low in beta carotene, leads to xerophthalmia (eyes failing to produce tears), which is a common cause of blindness in children of developing countries. Besides malnutrition, another reason this deficiency occurs is due to the defective storage and circulation of vitamin A in the body.

Symptoms of Vitamin A Deficiency

The different symptoms of vitamin A deficiency are as follows.

• Corneal inflammation
• Night blindness
• Poor vision
• Skin rash
• Lack of appetite and vigor
• Defective teeth and gums
• Retarded growth in children
• Dry and dull hair
• Dandruff
• Rough and dry skin
• Excessive hair loss
• Ridged nails
• Poor wound healing
• Poor sense of taste and smell
• Weakened immune system
• Prolonged and frequent common colds
• Formation of small, white spots in the inner eyelids
• Vulnerability to urinary and respiratory tract infections
• Keratinization (accumulation of keratin) of the skin
• Skin disorders: pimples, boils, premature wrinkles and acne
• Mucus formation ability of the body is hampered

Keratinization of the eyes results in xerophthalmia, which is a condition in which the tear glands of the eyes stop producing tears. Hence, the conjunctiva and cornea of the eye dry up, and become thick and wrinkled. If left untreated it can result in corneal ulceration and ultimately blindness. Night blindness can even lead to complete blindness if left untreated.

Vitamin A deficiency can be diagnosed with the help of blood tests, and by observing the different symptoms. The patient has to follow a diet plan comprising vitamin A rich food thereafter. Treatment involves intake of vitamin supplements that will raise the essential nutrient levels in the body. Pregnant women should take such vitamin supplements only under medical supervision. The supplements need to be administered under the guidance of a medical practitioner, or else the deficiency can develop into a case of toxicity of vitamin A. Thus, intake of the right amount of vitamin A has to be maintained.