dihydrotachysterol and Osteomalacia

Topics: 25-Hydroxyvitamin D 2; Calcitriol; Calcium; Cholecalciferol; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Ergocalciferols; Humans; Intestinal Absorption; Osteomalacia; Parathyroid Hormone; Vitamin D

Since the introduction of irradiated ergosterol into our food supply, nutritional vitamin D-deficiency rickets has become an uncommon disease. However, skeletal disorders due to abnormalities of vitamin D function still occur. These disorders can now be classified more exactly into two groups: those in which there is a deficiency of the active metabolite of vitamin D, 1,25-dihydroxyvitamin D, and those in which there is an abnormality of renal tubular function resulting in renal hypophosphatemia despite normal vitamin D metabolism. The various entities of these two groups are described and the theoretical basis of their treatment given.

Topics: Dihydrotachysterol; Fanconi Syndrome; Glycosuria; Humans; Hyperparathyroidism; Hyperparathyroidism, Secondary; Hypophosphatemia, Familial; Infant; Osteomalacia; Phosphates; Renal Aminoacidurias; Rickets; Vitamin D; Vitamin D Deficiency

Topics: Adipose Tissue; Animals; Bone and Bones; Calcium, Dietary; Cholecalciferol; Dihydrotachysterol; Ergocalciferols; Ergosterol; Fishes; Hormones; Humans; Intestinal Absorption; Intestine, Small; Keratins; Kidney; Liver; Muscles; Osteomalacia; Rickets; Sebaceous Glands; Skin; Skin Absorption; Ultraviolet Rays; Vitamin D

Topics: Aluminum; Bone Regeneration; Calcium; Calcium Carbonate; Cholecalciferol; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Dihydroxycholecalciferols; Ergocalciferols; Humans; Hydroxycholecalciferols; Intestinal Absorption; Osteitis Fibrosa Cystica; Osteomalacia; Parathyroid Glands; Phosphorus; Secretory Rate; Vitamin D

Fifteen patients with dialysis osteomalacia were treated with 24,25-dihydroxyvitamin D3 in dosages up to 10 micrograms per day for two to 24 months. All had previously had no improvement during treatment with calcitriol but had been remarkably susceptible to hypercalcemia. When 24,25-dihydroxyvitamin D3 was given with either calcitriol or dihydrotachysterol, serum calcium levels were significantly lower than during treatment with calcitriol or dihydrotachysterol alone. Eight of nine patients who received combined therapy with 24,25-dihydroxyvitamin D3 and calcitriol for longer than two months had clinical improvement; six patients underwent repeated bone biopsy and showed evidence of improved bone mineralization. Patients who received 24,25-dihydroxyvitamin D3 alone did not improve clinically. Since 24,25-dihydroxyvitamin D3 appears to improve calcium homeostasis and bone mineralization in some patients with severe dialysis osteomalacia when administered with 1-hydroxylated vitamin D metabolites, further controlled studies are warranted.

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Alkaline Phosphatase; Biopsy; Bone Resorption; Calcitriol; Calcium; Child, Preschool; Clinical Trials as Topic; Dihydrotachysterol; Dihydroxycholecalciferols; Drug Therapy, Combination; Female; Humans; Kidney Failure, Chronic; Male; Middle Aged; Osteomalacia; Renal Dialysis; Time Factors

Topics: Dihydrotachysterol; Female; Humans; Middle Aged; Osteomalacia; Primidone

Topics: Calcifediol; Calcitriol; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Humans; Osteitis Fibrosa Cystica; Osteomalacia; Renal Dialysis; Vitamin D

The biochemical changes observed in a patient with adult-onset hypophosphataemic osteomalacia after three weeks treatment with 1,25-dihydroxycholecalciferol (1,25-(OH)2D3) followed by dihydrotachysterol (DHT) are reported. The treatment with 1,25-(OH)2D3 resulted in restoration of intestinal phosphate absorption to normal with a small rise in plasma phosphate concentration; there was no significant change in tubular reabsorption of phosphate. The tubular reabsorption of bicarbonate, which was initially low, returned almost into the normal range with normalisation of plasma bicarbonate concentration. Aminoaciduria decreased. There were no changes in plasma or urinary calcium but immunoreactive parathyroid hormone (i-PTH) which was initially elevated fell but still remained above the normal range. These changes were maintained after replacing the 1,25-(OH)2D3 treatment with dihydrotachysterol (DHT).

Topics: Amino Acids; Bicarbonates; Calcium; Chlorides; Dihydrotachysterol; Dihydroxycholecalciferols; Ergocalciferols; Female; Humans; Hydroxycholecalciferols; Intestinal Absorption; Middle Aged; Osteomalacia; Phosphates

Topics: Adult; Alkaline Phosphatase; Aluminum Hydroxide; Bone and Bones; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Female; Humans; Hydroxyproline; Kidney Failure, Chronic; Male; Osteomalacia; Parathyroid Hormone; Phosphates; Renal Dialysis

Nine of 24 patients undergoing long-term hemodialysis were found to have evidence of moderate to severe bone disease. Two had bone pain and muscle weakness and two had pseudofractures. Eight of the nine were treated with dihydrotachysterol (DHT), 0.25 to 0.375 mg/d initially, but four required doses between 0.5 and 1.0 mg/d. Ther serum alkaline phosphatase value decreased in all patients and returned to normal in six. The bone pain and muscle weakness resolved and the pseudofractures healed. Bone biopsies in six patients before and after initiation of treatment with DHT showed that the osteoid area decreased significantly from 29.6 +/- 22.8% (mean +/- standard deviation) to 11.5 +/- 7.5% (P less than 0.025) and the resorptive surface decreased in all patients. DHT, in doses of up to 1.0 mg/d, is effective in treating both the osteitis fibrosa and the osteomalacic components of bone disease in patients undergoing hemodialysis.

Topics: Bone and Bones; Calcium; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Humans; Osteomalacia; Radiography; Renal Dialysis

Four patients who had been on regular haemodialysis for periods of 3 1/2 to 7 years became hypophosphataemic with plasma-phosphate concentrations of 2.5 mg/dl or less before dialysis. None of them had been taking oral phosphate-binders for 2 years or more. Histologically all the patients had an excess of osteoid on bone biopsy. Intestinal absorption of phosphate and calcium was impaired, despite normal or high serum-25-hydroxycholecaliferol concentrations. Treatment with oral dihydrotachysterol resulted in corrections of the phosphate malabsorption and increases in plasma-phosphate concentration. The initial low plasma-phosphate values in these patients before dialysis probably reflected a state of phosphate depletion caused by the combination of malabsorption, loss during dialysis, and a low dietary intake.

Topics: Adult; Bone and Bones; Deficiency Diseases; Dihydrotachysterol; Drug Evaluation; Female; Humans; Intestinal Absorption; Malabsorption Syndromes; Male; Osteomalacia; Phosphates; Renal Dialysis

We describe three patients with fibrous dysplasia of bone in whom there was evidence of hypophosphataemic osteomalacia or rickets. Two of the patients had polyostotic fibrous dysplasia and osteomalacia. The third was a child with fibrous dysplasia of the facial and cranial bones and rickets. In all cases the manifestations of osteomalacia or rickets were controlled with large doses of vitamin D. In the child the rickets and hypophosphataemia ceased when most of the bone affected by fibrous dysplasia was surgically resected. Previously reported cases of the association between fibrous dysplasia and hypophosphataemic osteomalacia are reviewed. We suggest that these cases are analogous to the syndrome of 'tumour rickets' where hypophosphataemia appears to be due to the presence of a mesenchymal tumour and regresses when the tumour is removed.

Topics: Adult; Calcium; Child; Dihydrotachysterol; Female; Fibrous Dysplasia of Bone; Humans; Male; Middle Aged; Osteomalacia; Phosphorus; Rickets; Vitamin D

Nine out of 24 patients on chronic hemodialysis were found to have biochemical, radiologic and bone biopsy evidence of moderate to severe bone disease. Two patients had bone pain and muscle weakness, 2 had pseudofractures, and one patient had a pathologic fracture of the neck of the femur. Eight patients were treated with dihydrotachysterol (D.H.T.), 0.25 to 0.37 mg/day initially. Four patients required doses between 0.5 and 1.0 mg daily. The alkaline phosphatase decreased in all patients, returning to normal in 6 patients. The symptoms of bone pain and muscle weakness resolved, and the pseudofractures healed. Repeat bone biopsies were performed in 6 patients 12 mos or more after treatment with D.H.T. The osteoid area fell from 29.6 +/- 22.8 to 11.5 +/- 7.5% (p less than 0.025). Resorptive surface decreased in all patients. D.H.T., in doses of up to 1.0 mg/day, is effective in the treatment of both the osteitis fibrosa and the osteomalacic component of bone disease in patients on hemodialysis.

Topics: Calcium; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Humans; Osteomalacia; Renal Dialysis

Four patients had symptomless osteomalacia at the time of starting regular haemodialysis. After 21-40 months they became hypophosphataemic and developed disabling skeletal symptoms. In each case an exacerbation of histological osteomalacia was shown. Symptoms improved after measures designed to raise serum inorganic phosphate concentrations or vitamin D administration, or both. Patients undergoing maintenance haemodialysis should have their serum phosphate and alkaline phosphatase levels monitored every month. Predialysis phosphate levels below 1 mmol/1 (3 mg/100 ml) and rising serum alkaline phosphatase concentrations are danger signals. If the diagnosis is confirmed early aggressive treatment should be started.

Topics: Adolescent; Adult; Alkaline Phosphatase; Calcium; Dihydrotachysterol; Female; Humans; Kidney Diseases; Male; Osteomalacia; Phosphates; Renal Dialysis

Topics: Chemical Phenomena; Chemistry; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Epilepsy; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Osteomalacia; Rickets; Vitamin D; Vitamin D Deficiency

Topics: Bone and Bones; Bone Diseases; Calcium Metabolism Disorders; Dihydrotachysterol; Humans; Osteomalacia; Vitamin D

Topics: Adolescent; Anticonvulsants; Body Height; Body Weight; Calcium; Child; Dihydrotachysterol; Epilepsy, Tonic-Clonic; Ergocalciferols; Humans; Hypocalcemia; Hypoparathyroidism; Male; Middle Aged; Osteomalacia; Rickets; Time Factors; Ultraviolet Therapy; Vitamin D

Topics: Animals; Bone Diseases; Calcium; Chemical Phenomena; Chemistry; Cholecalciferol; Dihydrotachysterol; Dihydroxycholecalciferols; Disease Models, Animal; Humans; Hydroxycholecalciferols; Isomerism; Kidney Failure, Chronic; Microradiography; Osteitis Fibrosa Cystica; Osteomalacia; Phosphates; Rats; Renal Dialysis; Uremia; Vitamin D

Topics: Adult; Alkaline Phosphatase; Calcium; Calcium Isotopes; Dihydrotachysterol; Gastrectomy; Humans; Hyperparathyroidism, Secondary; Intestinal Absorption; Magnesium; Male; Osteomalacia; Parathyroid Hormone; Phosphates; Phosphorus; Time Factors

Topics: Adult; Calcium; Diet Fads; Diet Therapy; Diet, Vegetarian; Dihydrotachysterol; Ergocalciferols; Female; Humans; Middle Aged; Osteomalacia; Phosphates; Vitamin D; Vitamin D Deficiency

Topics: Animals; Dihydrotachysterol; Humans; Hypoparathyroidism; Osteomalacia; Rickets; Vitamin D

Topics: Acidosis; Acidosis, Renal Tubular; Adenoma; Celiac Disease; Diagnosis, Differential; Dihydrotachysterol; Electromyography; Humans; Hyperparathyroidism; Muscular Atrophy; Muscular Diseases; Osteomalacia; Parathyroid Neoplasms; Prednisone; Radiography; Sprue, Tropical

Topics: Adenoma; Calcium; Calcium Phosphates; Dihydrotachysterol; Drug Therapy; Glycosuria; Glycosuria, Renal; Humans; Kidney; Kidney Diseases; Kidney Tubules; Osteomalacia; Parathyroid Neoplasms; Phosphates; Urine

Topics: Adolescent; Alkaline Phosphatase; Calcium; Calcium, Dietary; Dihydrotachysterol; Glycine; Humans; Hypophosphatemia; Metabolism; Osteomalacia; Phosphates; Phosphorus; Phosphorus Metabolism Disorders; Phosphorus, Dietary; Renal Aminoacidurias

Topics: Alkaline Phosphatase; Calcium; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Humans; Hypophosphatemia; Kidney; Osteomalacia; Phosphates; Phosphorus; Phosphorus Metabolism Disorders; Renal Tubular Transport, Inborn Errors; Rickets; Urine; Vitamin D