Are nucleotides essential nutrients?
Widmaier et al. (2004) defined an essential nutrient as a substance required for normal or optimal body function, but synthesized by the body either not at all or in amounts inadequate to prevent disease. According to Grimble and Westwood (2000), nucleotides can be synthesized in the body. There is no biochemical reason why dietary nucleotides should be considered essential nutrients. Pathways for their synthesis or salvage are (with no exception) present in every tissue, and interorgan traffic should provide sufficient substrate for any tissue with increased requirement for DNA and RNA turnover. Nevertheless, this model of metabolic complacency has been punctured by research that suggests that dietary nucleotide deficiency may impair liver, heart, intestinal and immune function. Interestingly, McDowell (1989) indicated in his book Vitamins in Animal Nutrition that yeast was one of the most important sources of vitamins in the beginning of the 20th century. The question now is: Was it
