This vitamin is produced in the body with sunlight. You can also acquire it by eating eggs, fortified milk, fish-liver and oils. Whether it is made in the skin or comes from food it has to be activated before it's of use to the body. First, it travels to the liver where it undergoes a chemical change. Then it moves through the blood stream to the kidneys, where it undergoes another change to become the active form of the vitamin. This active form (dihydroxy vitamin D) is the one that helps the body absorb calcium and phosphorus. (Knowledgecenter, 1998) Vitamin D deficiency causes rickets in children and osteomalacia in adults. The bone becomes soft and deformed. One of Rickets common signs is bowlegs, or bead like swelling on the ribs. Teeth can also be susceptible to decay. Minerals in the bones, specifically calcium, are lost when you have osteomalacia. (Mader, 2001).
Vitamin C, also known as ascorbic acid, seems to have many functions in the body. The major function is its role in the formation and repair of collagen. Collagen is the connective tissue that holds the body's cells and tissues together, such as blood vessels, skin, tendons, and ligaments. Vitamin C is consumed when citrus fruits, tomatoes, and green vegetables are eaten. In a deficiency of ascorbic acid wounds don't heal since collagen isn't produced. Also, bones fail to grow and small blood vessels rupture. A classic disease is scurvy where defective collagen is formed. Early signs are bleeding gums and bleeding under the skin, which causes tiny pinpoint bruises. This disease can cause poor wound healing and anemia. (Knowledgecenter, 1998).
Vitamin B12 (cyanocobalamin) is essential to cells because it's needed to make DNA and RNA, which carry and transmit genetic information for every living cell. This information tells a cell how to function and must be passed along each time a cell divides.
