Comparison of the appearance of radiolabelled vitamin D3 and 25-hydroxy-vitamin D3 in the chylomicron fraction of plasma after oral administration in man.
1. The uptake of either orally administered [3H]vitamin D3 or 25-[3H]hydroxy-vitamin D3 into the chylomicron fraction of plasma was studied in 12 healthy male subjects. 2. The amount of [3H]vitamin D3 in the chylomicron fraction expressed as a percentage of the total plasma radioactivity was higher than that of 25-[3H]hydroxy-vitamin D3. 3. It is suggested that the mechanism of intestinal absorption of vitamin D and 25-hydroxy-vitamin D may differ in man, the absorption of 25-hydroxy-vitamin D possibly being less dependent on bile acids.
D000284:Administration, Oral; D000328:Adult; D002112:Calcifediol; D002762:Cholecalciferol / Q000008:administration & dosage / Q000097:blood*; D002914:Chylomicrons / Q000378:metabolism*; D006801:Humans; D006887:Hydroxycholecalciferols / Q000008:administration & dosage / Q000097:blood*; D007408:Intestinal Absorption; D008297:Male; D014316:Tritium
D002914:Chylomicrons; D006887:Hydroxycholecalciferols; D014316:Tritium; D002762:Cholecalciferol; D002112:Calcifediol