A review is given of the literature concerning the so-called plant induced calcinosis in animals (tabel I), i.e. diseases which in their patological-anatomical appearance show great similarities with vit. D-intoxication. The etiology of the diseases are discussed in view of the last 5--10 years rapid development of knowledge concerning vit. D3 metabolism. It is pointed out that the most recent results indicate that enzootic calcinosis is caused by a 1,25-dihydrocholecalciferol-glycoside, which is hydrolysed in the intestinal tract. By this reaction 1.25 (OH) 2 cholecalciferol--the biological active metabolite of vit. D3 -- is set free, and thus able to act directly on the intestinal absorption mechanism. By this reaction the point of calcium metabolism regulation is essentially by-passed and calcium and phosphate absorption proceeds essentially out of control, causing hypercalcaemia, hyperphosphataemia, hypersecretion of calcitonin and calcinosis.