[25-hydroxycholecalciferol and 24,25-dihydroxycholecalciferol content on rat tissues in vitamin D poisoning]

As vitamin D3 dose increases, the level of 25-hydroxycholecalciferol in the blood plasma, liver, kidneys, small intestine, bones and muscles of rats rises. The maximum concentration and maximum content of 25-hydroxycholecalciferol with reference to the entire tissue growing with vitamin D3 dose increase are characteristic for the osteal tissue. The synthesis of excess quantities of 25-hydroxycholecalciferol is followed by formation of a metabolite that is similar to 24,25-dioxycholecalciferol from the standpoint of chromatographic mobility. The metabolite is accumulated in the kidneys, intestine, blood plasma and to a less measure in the osteal tissue. No metabolite could be detected in the liver or muscles.