A greater number of deaths result from vitamin A deficiency than those caused by virtually all other deficiencies combined. The deaths largely occur in poor countries. However, increasingly, deaths are being attributed to vitamin A deficiency in Westernized countries. In children, adolescents, and the elderly lack of vitamin A greatly increases the risks for potentially life-threatening infections. The deficiency is also associated with numerous gastrointestinal diseases, the most severe of which is chronic or acute diarrhea. Diarrhea due to vitamin A deficiency afflicts tens of millions of individuals yearly, causing millions of deaths world-wide. This vitamin largely controls the synthesis and reproduction of all cells. It is required for protein synthesis and hormone production. A lack of vitamin A exerts a negative effect upon every organ in the body and may lead to severe damage of the intestinal tract, immune system, joints, bones, and hormonal glands.