Vitamin C and the common cold by 18%. Severity was also reduced. However, if vitamin C was started only when the first symptoms of a cold were being felt, there were no benefits for duration or severity. Vitamin C and the common cold The common cold, or simply cold, is a viral infectious disease of the upper respiratory tract. The cold is indeed common, and is a significant cause for absences from work and school. Even before the discovery of vitamin C, folklore had it that certain fruits were effective in both preventing and treating the cold. After scientific identification of vitamin C in the early
Vitamin deficiency Vitamin deficiency A vitamin deficiency can cause a disease or syndrome known as an avitaminosis or hypovitaminosis. This usually refers to a long-term deficiency of a vitamin. When caused by inadequate nutrition it can be classed as a "primary deficiency", and when due to an underlying disorder such as malabsorption it can be classed as a "secondary deficiency". An underlying disorder may be metabolic as in a defect converting tryptophan to niacin. It can also be the result of lifestyle choices including smoking and alcohol consumption. Examples are vitamin A deficiency, folate deficiency, scurvy, vitamin D deficiency, vitamin E deficiency,