Historical aspects of minerals and vitamins in parenteral nutrition

Advances in knowledge of the requirements for vitamins and minerals have been essential in the success of total parenteral nutrition (TPN) for improving or maintaining good nutritional status for increasing periods of time. The availability of all known vitamins by the late 1940's and advances in vitamin technology resulted in stable single-vitamin or multivitamin solutions for i.v. use. Improved physician experience in vitamin usage and modified and more complete formulations are reflected in improved patient treatment. However, requirements for certain vitamins in hypermetabolic states and for prolonged use remain to be elucidated. TPN has also focused attention on the needs for macro- and microminerals. It has emphasized the importance of electrolytes, including inorganic phosphate, in human nutrition. Changes in the sources of amino acids from protein hydrolysates to crystalline amino acids have resulted in increasingly purified solutions essentially free of trace elements. This has focused attention on human requirements and the need for provision of increasing numbers of these ions.