Deficiency
 Introduction
 Vitamin A deficiency is caused by lack of vitamin A nutritional disorders. Children deficient in vitamin A, the first night blindness, followed by degeneration of the body skin and epithelial tissue of secondary infection. Causes insufficient intake, poor absorption, excessive consumption and metabolic disruption and so on. The disease is more common in infants and young children.

 Performance
 1, decreased dark adaptation, night blindness, xerophthalmia, and dry eye, theres complete removal of corneal softening perforation caused the blind spot
 2. Mucosa, epithelial changes
 3. Growth retarded susceptible to respiratory infections
 4. Taste, smell less, loss of appetite
 5. Hair dry, rough skin, follicular keratosis, memory loss, feelings of irritability and insomnia.
 CAS Number :68 -26-8

 Prevention and treatment
 Mild vitamin A deficiency may be due to malabsorption (such as bowel disease, gastrectomy), metabolic abnormalities (fever), or excessive loss (glomerulonephritis) occurs, remove the risk factors, given vitamin A rich foods, such as the liver , chicken, goat, milk, egg yolk, carrots, spinach, leeks, shepherds purse, lettuce leaf, lily flowers, or dried apricots and other fruit. Given large doses of vitamin A, daily oral administration of 20-30 million international units, if the oral absorption, intramuscular injection can be changed, the general improvement in a month or so after 3-4 months of recovery, should pay attention to long-term use of Vitamin A large number of applications generate too much vitamin A disease. If combined with other vitamin deficiency, add accordingly.

 Recent studies show that vitamin A deficiency in the region, annually or every six months oral administration of 300,000 units of retinol droplets, can play a preventive role.

  Too many cases of vitamin A, is common in long-term use of vitamin A in children, the symptoms of the disease is skin changes (dry and rough skin), hepatomegaly and joint pain and so on. Just stop giving vitamin A, the symptoms will disappear.