Vitamin C, or ascorbic acid, is water-soluble and easily destroyed. It is essential in wound healing and in the formation of collagen, a protein important in the formation of healthy skin, tendons, bones, and supportive tissues. Deficiency results in defective collagen formation and is marked by joint pains, irritability, growth retardation, anemia, shortness of breath, and increased susceptibility to infection. Scurvy is the classic disease related to deficiency. Symptoms peculiar to infantile scurvy include swelling of the lower extremities, pain upon flexing them, and bone lesions. Excessive ascorbic-acid intake can cause kidney stones, gastrointestinal disturbances, and red-blood-cell destruction.