Vitamins are organic molecules that are required in the diet in small amounts for normal metabolic function. In most cases vitamins are required as cofactors for enzymes in metabolic pathways (although vitamin E and vitamin C for example act as lipid and water soluble antioxidants, respectively). The proteinaceous component of many enzymes require specific vitamins because they contain particular charges that shape to the protein or provide other structural or chemical characteristics to allow its catalytic activity. Low intakes of vitamins deprive enzymes of these essential cofactors and the proteins that comprise the enzyme are therefore not able to function and metabolic pathways cease to function. The severity of the disease associated with particular vitamins will vary depending on the degree of deprivation in the diet. Below a particular threshold, all vitamin deficiencies tend to cause death, with the B vitamins being some of the best described in this regard (here).
Increasingly the typical Western diet is being identified as having a low content of many of the essential micronutrients, including vitamins. Many studies have measured vitamin intakes in developed nations and found many of the vitamins lacking from the diet. This relates to the refined nature of the carbohydrate foods which include mainly refined white flour and refined crystalline sugars. Further, many of the vitamin rich foods such as fruits and vegetables are not consumed in great enough quantities. While the general population has been shown to have borderline low intakes of many vitamins, particular at risk groups have been identified within Western populations. These include the elderly and infirm. The elderly are at risk of vitamin deficiencies because absorption rates decline with advancing age and because food intakes fall significantly in the elderly. Hospital patients often have poor nutritional status and this may relate to their baseline nutritional states in combination with poor quality hospital foods.
For example, the intakes, clinical symptoms and biochemical parameters relating to vitamin B1, B2, B6 and vitamin C were investigated in over 600 hospital patients in France1. The intakes of the patients were lower than the Recommended Daily Allowances (RDAs) for vitamin B1, B2, B6 and vitamin C in 57, 47, 53 and 9 % of the patients. The intakes of vitamin B1, B2, B6 and vitamin C were less than half the RDA in 19, 12, 15 and 3 % of the patients, respectively. Biochemical deficiencies were detected for vitamin B1, B2, B6 and vitamin C in 25, 11, 25 and 14 % of the patients. The authors noted that the clinical symptoms of the patients correlated with the recorded intakes for the vitamins strongly. Clinical symptoms of vitamin deficiencies included tooth loss, periodontitis, caries, ocular signs, debility and anorexia. The authors also noted that the vitamin deficient patients also showed a wide range of general symptoms, suggesting that these patients were suffering from general malnutrition.
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