what does its deficiency cause?
Blindness
Vitamin A
Vitamin A deficiency is estimated to affect approximately one third of children under the age of five around the world. It is estimated to claim the lives of 670,000 children under five annually. Between 250,000 and 500,000 children in developing countries become blind each year owing to vitamin A deficiency, with the highest prevalence in Africa and southeast Asia. Vitamin A deficiency is "the leading cause of preventable childhood blindness", according to UNICEF. It also increases the risk of death from common childhood conditions such as diarrhea. UNICEF regards addressing vitamin A deficiency as critical to reducing child mortality, the fourth of the United Nations' Millennium Development Goals.
what is metabolism? The set of life-sustaining chemical reactions in organisms. what are the key biochemicals? Amino acids, carbohydrates, nucleic acid and lipids how is the name of the second one formed? Carbon + hydrogen + oxygen (usually with a hydrogen–oxygen atom ratio of 2:1 as in water) can you tell me about its structure? A typical monosaccharide has the structure H–(CHOH)(C=O)–(CHOH)–H how is the aforementioned structure cyclised? The open-chain form of a monosaccharide often coexists with a closed ring form where the aldehyde/ketone carbonyl group carbon (C=O) and hydroxyl group (–OH) react forming a hemiacetal with a new C–O–C bridge. what can you tell me about the fourth biochemical mentioned above? Often called fats, they are hydrophobic biological molecules but will dissolve in organic solvents such as alcohol, benzene. what is its role in our health? To  facilitate absorption of fat-soluble vitamins A, D, E, K and carotenoids; what are the other sources of the first vitamin? Carrots
wiki:5382393
Vitamin A [SEP] Deficiency
Vitamin A deficiency is estimated to affect approximately one third of children under the age of five around the world. It is estimated to claim the lives of 670,000 children under five annually. Between 250,000 and 500,000 children in developing countries become blind each year owing to vitamin A deficiency, with the highest prevalence in Africa and southeast Asia. Vitamin A deficiency is "the leading cause of preventable childhood blindness", according to UNICEF. It also increases the risk of death from common childhood conditions such as diarrhea. UNICEF regards addressing vitamin A deficiency as critical to reducing child mortality, the fourth of the United Nations' Millennium Development Goals.