Ancient Egyptians discovered that eating liver could cure night blindness -- an intriguing early case of treating a disease caused by vitamin A deficiency. Although certain chronic ailments can increase your risk, if you live in a developed nation like the United States or Canada, your chances of suffering from a vitamin A deficiency are quite low. Worldwide, however, the National Institutes of Health estimates that up to 500,000 malnourished children go blind every year because of diets that lack enough vitamin A.
About Vitamin A
Besides being essential to healthy vision, vitamin A protects you from infection by helping to produce white blood cells. Vitamin A also helps maintain the linings of your respiratory, urinary and intestinal systems. People who develop deficiencies have usually been experiencing a dietary deficiency of vitamin A for an extended period of time. Good dietary sources of the vitamin include beef and chicken liver, fortified low-fat milk, cheese, whole milk and eggs. Plant-based sources include carrots, spinach, kale and cantaloupe.
Deficiency Risks
Vitamin A deficiency is a particular hazard in parts of the world where rice, which is lacking the vitamin, is a diet staple. Further, if you're a vegetarian who does not eat eggs or dairy products, you will need to pay close attention to the fruits and vegetables you eat, choosing plenty that are rich in vitamin A. You might also develop a deficiency if you have a pancreatic disorder or a digestive ailment, such as celiac or Crohn's disease. Drinking too much alcohol also raises the risk of a deficiency. The recommended daily dose for boys who are 14 years old and over is 900 mcg. For girls who are 14 years old and over, the recommended daily dose is 700 mcg.
Symptoms and Diseases
A lack of vitamin A can cause extreme dryness and damage to the cornea and retina. This contributes to night blindness, an early sign of vitamin A deficiency. Complete blindness may result if the deficiency is long-term. People who do not consume enough vitamin A are also less able to fight infection and more susceptible to complications of infectious diseases. Other symptoms can include dry and scaly skin, respiratory infections and retarded growth in children.
Vitamin A Treatments
Your doctor may advise vitamin A supplements if you have a digestive disorder or other ailment that puts you at risk for deficiency. Topical and oral medications containing synthetic retinoids, a vitamin A derivative, are used to treat some skin disorders, such as acne. A balanced, healthy diet is the best way to ensure you get enough vitamin A, though it is possible to get too much, especially through supplements. Possible toxic effects range from nausea and headache to birth defects, liver ailments and nervous system disorders.
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