why is vitamin a deficiency common in developing countries
Vitamin A deficiency The major cause is roughage which include few animal sources of pre-formed vitamin A.[citation needed] In addition to dietary problems, there are other causes of VAD. Iron deficiency can affect vitamin A uptake. Excess alcohol consumption can deplete vitamin A, and a stressed liver may be more susceptible to vitamin A toxicity. People who consume large amounts of alcohol should seek medical advice before taking vitamin A supplements. In general, people should also seek medical advice before taking vitamin A supplements if they have any condition associated with fat malabsorption such as pancreatitis, cystic fibrosis, tropical sprue and biliary obstruction. Other causes of Vitamin A deficiency are inadequate intake, fat malabsorption, or liver disorders. Deficiency impairs immunity and hematopoiesis and causes rashes and typical ocular effects (e.g., xerophthalmia, night blindness).[17]