“…We have become conversant in recent years with the importance of the relationship between ossification, parathyroid hormone, vitamin D and the 'Krebs cycle' (Glanzmann, Meier and Walthard, 1946;Heinz, Miller and Rominger, 1947;Harrison and Harrison, 1952a;Nordio, Semach and Grego, 1956; de Toni, 1957). In rickets the citric acid level in the blood and urine is diminished (Harrison, 1954;Nordio et al, 1956).…”