R. Hume

Relationship between total body water and surface area in normal and obese subjects

Total body water was measured using tritium in 30 males and 30 females. It was found that total body water could be predicted from height and weight, and formulae for both males and females have been produced with multiple correlation coefficients (r) of 0·95 and 0·96 respectively. The predicted total body water was found to be very closely related to the predicted surface area giving correlation coefficients (r) for males and females of 0·997 and 0·985 respectively.

The relation of total body potassium to height, weight, and age in normal adults

Total body potassium was measured in 103 healthy adults using a shadow-shield whole-body monitor of high sensitivity. The range of height was 147 to 192 cm, of weight 43 to 92 kg, and of age 18 to 77 years. The values obtained for total body potassium were correlated with height, with weight, and with height and weight. Age was then included as an additional variable. The standard deviation from regression was smaller when total body potassium was correlated with height than with weight and was further reduced, to about 9%, in a multiple regression using height and age. The advantages of this relationship over indices involving weight are discussed. The smallest standard deviation from regression, 7·5%, was obtained when total body potassium was correlated with height, weight, and age. The usefulness of this relationship is discussed with comment on its limitations. A regression equation was derived between lean body mass (derived from height and weight) and total body potassium with a standard deviation from regression of 5·5% in males and 7·3% in females.

CHANGES IN LEUCOCYTE ASCORBIC ACID DURING THE COMMON COLD

Leucocyte ascorbic acid was measured in 7 subjects during the common cold. There was a significant fall in L.A.A. to scorbutic levels within 24 hours of the onset of symptoms. By the fifth day the L.A.A. had returned to normal, which coincided with the cessation of symptoms. Absorption studies suggested 1g. ascorbic acid per day as a prophylactic dose and 6g. ascorbic acid per day as a therapeutic dose. The effect of such supplements of ascorbic acid in 4 episodes of the common cold in 3 subjects suggests that the L.A.A. pattern can be changed by this therapy. The implications are discussed.

The effect of megadose ascorbic acid ingestion on the absorption and retention of vitamin B12 in man.

Radiotracer B12 analogues, hydroxy- and cyano-cobalamin have been used to study the effects of megadose L-ascorbic acid (vitamin C) ingestion on vitamin B12 metabolism in man. By employing whole body counter techniques it has been shown that, while absorbic acid can partially inactivate both the important dietary analogue, hydroxycobalamin, and the gastric secretion, intrinsic factor which is essential for B12 absorption, the rapid binding of the B12 analogue to intrinsic factor protects the hydroxycobalamin from attack. As a result, the absorption of hydroxycobalamin is unaffected by the simultaneous ingestion of 1 g ascorbic acid. The absorption of cyanocobalamin, the most stable analogue but not found in quantity in the diet, is slightly increased by ascorbic acid. Whole body retention studies on normal subjects ingesting 2 g ascorbic acid per day show no significant evidence of in vivo destruction of body B12 stores.