Author: Glossary

Vitamers of vitamin A.  

Immature precursor of the red blood cell in which the remains of the nucleus are visible as a reticulum. Very few are seen in normal blood as they are retained in the marrow until mature, but on remission of anaemia, when there is a high rate of production, reticulocytes appear in the bloodstream (reticulocytosis). Immature…

Ratio of the volume of carbon dioxide produced when a substance is oxidised, to the volume of oxygen used. The oxidation of carbohydrate results in an RQ of 1.0; of fat, 0.7; and of protein, 0.8. Ratio of the amount of carbon dioxide produced to the amount of oxygen consumed at cellular level. The ratio…

Concentration of a compound in the blood above which it is not reabsorbed by the kidney, and so is excreted in the urine. Concentration of a substance in plasma at which it is excreted in urine. The concentration at which a substance in the blood normally not excreted by the kidney begins to appear in…

Rate of passage of plasma through the kidneys, directly related to glomerular filtration rate.  

A measure of protein quality.  

These refer to databases recording the linear and ponderal growth of healthy children. They include anthropometric data collected on suitably large samples, and analysed with precise specifications to provide a useful basis for reference.  

Defined by COMA (Committee on Medical Aspects of Food Policy for the UK Department of Health), most recently in 1991, as being the amount of each nutrient that is sufficient to meet the needs of the majority (mean +2 standard deviations) of healthy people in a defined population, or subgroup of it. Approximately equivalent (in…

An arbitrary physiological standard; defined as a person aged 25, weighing 65 kg, living in a temperate zone of a mean annual temperature of 10°C. Reference man performs medium work, with an average daily energy requirement of 13.5 MJ (3200 kcal). Reference woman is engaged in general household duties or light industry, with an average…

Amounts of nutrients greater than the requirements of almost all members of the population, determined on the basis of the average requirement plus twice the standard deviation, to allow for individual variation in requirements and thus cover the theoretical needs of 97.5% of the population.