RESUMEN
The solanum molacoxylon (SM) is a plant which grows in South America, whose leaves produce a calcinosis on animal farms. In the aquous extract of the leaves a glycoside of 1, 25 (OH)2D3 has been found. The aquous extracts of the leaves of SM provokes an increase of intestinal calcium absorption without any transformation, because it is active in total nephrectomized animal. If this extract is given during a short time the bone resorption is dramatically increased, nevertheless if it is given chronically an increase of bone formation with an osteosclerosis is observed. This plant increases the plasma and urinary calcium and sometimes the plasma phosphorus. In acute administration the urinary hydroxyproline increases. A few therapeutic assays were done in humans with similar results. These assays suggest that SM could be a natural source of 1,25 dihydroxycholecalciferol.