Published online by Cambridge University Press: 09 August 2018
It was nearly 120 years ago that the physiologist Claude Bernard proposed that for an organism to function optimally the component cells must be surrounded by a medium of closely regulated composition (‘La fixité du milieu interne est la condition de la vie libre’). Homeostasis is the term used today to describe this phenomenon, being first coined by Walter B. Cannon in 1929 (Hardy, 1976). This is the underlying physiological principle that explains the relative chemical constancy of the body, including inorganic nutrients such as Fe.