No demonstrable accumulation of 14C-vitamin D3 in developing rat teeth and bones

The distribution of 14C-vitamin D3 administered subcutaneously in arachidic oil to 6-day-old suckling rats has been examined autoradiographically. The animals were sacrificed 1, 2, 4 and 8 days after injection. The autoradiographic exposure time was 4 months. The sectioning and exposure was performed in a freeze-room. Radioactivity was found mainly in the liver, kidney, intestines and fat depots. No uptake was found in developing teeth or bones.