Vitamin D balance and distribution in rats given a massive dose of ergocalciferol: Part I. Experimental results

Studies of Antiricketic Activity in Sera From Patients With Disorders of Calcium Metabolism and Preliminary Observations on the Mode of Transport of Vitamin D in Human Serum*

“…The results obtained on human subjects in the present experiments and previously, also, by Warkany (10)(11)(12) are consistent with the findings of Cruickshank and his co-workers (33)(34)(35). We found that ingestion of large doses of vitamin D were required to increase appreciably the antiricketic activity of the serum.…”

“…Recently several studies have been reported on the fate of orally administered vitamin D in experimental animals (33,34). Following such administration only a small fraction (10 to 30 per cent) of the dose could be recovered, the major portion having been destroyed, presumably within the intestinal lumen.…”

“…Following such administration only a small fraction (10 to 30 per cent) of the dose could be recovered, the major portion having been destroyed, presumably within the intestinal lumen. It has been suggested that oxidation of the D vitamins within the gut may account for their disappearance after oral dosage and that the bacterial flora of the gut may be the responsible agents (33,34). In one test of this possibility succinylsulfathiazole was fed to a group of rats prior to D administration, but this did not result in any improved recovery of the vitamin (35).…”

Déficit de vitamina D y morbimortalidad en pacientes críticos pediátricos

“…Windaus y cols. (62) , en 1936, y Schenck (63) , en 1937, pensaban que la vitamina D actuaba en todo el cuerpo sin alteración, pero posteriormente Cruickshank y Kodicek (64,65) , en 1953 y 1954, plantearon que la vitamina D debía metabolizarse antes de iniciar sus funciones. Kodicek y colaboradores (65,66) , en 1955, aislaron la vitamina D 2 .…”

Metabolism of Vitamin D

“…Work in Kodicek's laboratory (Cruickshank and Kodicek, 1953) showed, however, that after massive doses of vitamin D2 little if any antirachitic activity could be recovered from lipid extract of rat tissues. Early attempts to study the metabolism of vitamin D were hampered by the problem of producing radioactive vitamin of sufficiently high specific activity to allow it to be recovered after chromatography and have its physiological activity tested.…”