24-25-dihydroxyvitamin-d-3 and Postoperative-Complications

A prospective study was made of sequential changes in the metabolism of vitamin D and calcium in 19 allograft recipient during the first year after successful renal transplantation. All but one of the patients received cyclosporine A combined with corticosteroids and azathioprine as immunosuppressive therapy. Shortly after transplantation most patients showed transient hypocalcemia and hypophosphatemia. At the time of transplantation 17 of 19 patients had an elevated plasma intact parathyroid hormone (PTH) level, and at the close of follow-up one in four patients. In six other patients intact PTH was within the reference range, but high in relation to simultaneously measured serum ionized calcium. According, one year after transplantation less than half of the patients showed complete resolution of hyperparathyroidism. The change towards normal in the metabolism of vitamin D began within the first post-transplantation week irrespective of the onset of diuresis. One to two weeks after transplantation 1,25(OH)2D3 and 24,25(OH)2D3 reached the lower limit of normal range. In these renal allograft recipients who received cyclosporine A the long-term values of serum 1,25(OH)2D3 did not differ from those of normal subjects.

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Calcifediol; Calcitriol; Calcium; Chronic Kidney Disease-Mineral and Bone Disorder; Creatinine; Female; Follow-Up Studies; Humans; Kidney Failure, Chronic; Kidney Function Tests; Kidney Transplantation; Male; Middle Aged; Osteocalcin; Parathyroid Hormone; Phosphates; Postoperative Complications; Prospective Studies; Serum Albumin; Vitamin D

Thirty-six unselected patients were investigated 3-24 years (mean, 7.8 years) after small-bowel resection for Crohn's disease (mean small intestinal resection, 105 cm). Iliac crest bone biopsies after in vivo tetracycline double-labelling showed a markedly reduced trabecular bone mass (controls, 0.25 +/- 0.06; patients, 0.15 +/- 0.05; p less than 0.01). The average bone remodeling and osteoid mineralization was normal, and only two patients demonstrated signs of frank but slight osteomalacia. The mean serum levels of the three vitamin D metabolites 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D were normal. The observed reduction in trabecular bone mass may theoretically be followed by an increased risk of spontaneous fractures.

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Aged; Bone and Bones; Calcifediol; Calcitriol; Crohn Disease; Dihydroxycholecalciferols; Female; Humans; Intestine, Small; Male; Middle Aged; Photometry; Postoperative Complications; Tetracycline; Vitamin D

Ten obese subjects who had undergone intestinal bypass operation (end-to-side jejunoileostomy) were studied longitudinally with respect to vitamin D and other indices of calcium metabolism. Investigations were carried out before operation (t0) and after 6 months (t1), 12 months (t2), and a mean of 54 months (range, 49-58 months) (t3) postoperatively. Serum 25-hydroxyvitamin D (25OHD) was subnormal at t0 but after operation values declined gradually to an extremely low level at t3, possibly because of a loss through malabsorption. Serum 24,25-dihydroxyvitamin D remained normal at t1 and t2 but fell to about half the normal level at t3, probably owing to lack of its precursor, 25OHD. In contrast, serum 1,25-dihydroxyvitamin D (1,25(OH)2D) remained normal throughout the study, indicating a marked stimulation of kidney 1 alpha-hydroxylase activity. Serum calcium fell rapidly to a constant subnormal level, and it is concluded that the serum calcium malabsorption is due to factors other than impaired 1,25(OH)2D activity. Bone mineral content (BMC) was unchanged between t0 and t2, but thereafter (between t2 and t3) the mean BMC fell rapidly to about 90% of preoperative value, possibly due to a defective bone mineralization in the late postoperative period. The findings indicate a high risk of bone disease developing after intestinal bypass operation. Substitution with calcium and vitamin D should be given to these patients, but the optimal vitamin D metabolite (or combination of metabolites) for such treatment is still unknown.

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Alkaline Phosphatase; Bone and Bones; Calcifediol; Calcitriol; Dihydroxycholecalciferols; Female; Humans; Hydroxycholecalciferols; Ileum; Jejunum; Longitudinal Studies; Male; Minerals; Obesity; Postoperative Complications