Tolerance to 1,25 dihydroxyvitamin D-3 glycosides from Solanum glaucophyllum by the growing pig

摘要

Solanum glaucophyllum leaves contain high levels of glycosidically bound 1,25 dihydroxyvitamin D-3, the most important vitamin D metabolite. The tolerance to this source was evaluated during six weeks with fifty weaned pigs fed increasing levels (0, 2.5, 5, 10 and 20 mu g 1,25(OH)(2)D-3/kg diet). The diet contained, per kg, 9.7 g Ca, 3.5 g digestible P and 2000 IU cholecalciferol. Ten additional pigs were fed a diet containing 1000 IU cholecalciferol/kg, without 1,25(OH)(2)D-3. Weekly plasma and final kidney, bone and urinary mineral contents, bone density and breaking strength served as indicators for possible adverse effects of the supplement. All animals grew well and remained clinically healthy. The measured parameters remained unchanged when 1000 replaced 2000 IU cholecalciferol/kg and when 1,25(OH)(2)D-3 was fed up to 10 mu g/kg. Twenty mu g 1,25(OH)(2)D-3 increased plasma Ca and decreased plasma P from the 2nd and the 4th experimental week onwards, respectively. Twenty mu g 1,25(OH)(2)D-3 increased final plasma Ca and 1,25(OH)(2)D-3 and reduced final plasma P by respectively 19, 56 and 13%. Twenty mu g 1,25(OH)(2)D-3 also increased kidney Ca and urinary Ca by 43 and 69%, respectively, reduced bone breaking strength by 12% and tended to decrease bone ash by 3%. To conclude, 2000 IU D-3 was not beneficial compared to 1000 IU cholecalciferol; up to 10 mu g 1,25(OH)(2)D-3 per kg diet did not lead to observed adverse effects; 20 mu g 1,25(OH)(2)D-3 altered the homeostatic regulation of Ca and P thus, may lead to first signs of possible adverse effects, such as soft tissue calcification. (C) 2017 The Authors. Published by Elsevier Ltd.