cholecalciferol and Hypophosphatemia--Familial

Topics: Adolescent; Adult; Child, Preschool; Cholecalciferol; Fanconi Syndrome; Female; Humans; Hypophosphatemia, Familial; Male; Osteomalacia; Osteoporosis; Phosphates; Vitamin D

Topics: Amino Acid Sequence; Animals; Base Sequence; Cholecalciferol; Humans; Hypophosphatemia, Familial; Molecular Sequence Data; Protein Conformation; Receptors, Calcitriol; Receptors, Steroid; Transcription, Genetic; Transcriptional Activation

Topics: Alkaline Phosphatase; Animals; Bone and Bones; Calcifediol; Calcitriol; Calcium; Callitrichinae; Cebidae; Cercopithecidae; Cholecalciferol; Disease Models, Animal; Hypophosphatemia, Familial; Intestinal Mucosa; Kidney; Liver; Parathyroid Hormone; Phosphorus; Receptors, Calcitriol; Receptors, Steroid

Topics: Animals; Antibodies, Monoclonal; Biological Evolution; Bone and Bones; Calcifediol; Calcitriol; Calcium; Cattle; Cell Differentiation; Cell Division; Cell Nucleus; Chickens; Cholecalciferol; Cytosol; Homeostasis; Humans; Hypophosphatemia, Familial; Immunity; Intestinal Mucosa; Macromolecular Substances; Mice; Minerals; Molecular Weight; Neoplasms; Radioligand Assay; Rats; Receptors, Calcitriol; Receptors, Steroid; Tissue Distribution

Topics: Animals; Calcitriol; Calcium; Cell Nucleus; Cells; Chickens; Cholecalciferol; Gene Expression Regulation; Homeostasis; Humans; Hypophosphatemia, Familial; Mice; Minerals; Phosphorus; Receptors, Calcitriol; Receptors, Steroid; Rickets; Structure-Activity Relationship; Tissue Distribution; Transcription, Genetic

Diagnostic and therapeutical uses of vitamin D3 and its metabolites are reviewed. Special emphasis is dedicated to the fetomaternal relationships of 1,25 (OH)2 D3 and 25-OH-D3 at term. The serum levels of 1,25 (OH)2 D3 have been found to be higher in the maternal serum then in the corresponding fetus (85.3 pg/ml and 50.9 pg/ml, respectively). The highest serum levels of 1,25 (OH)2 D3 were found in October and the lowest ones in January showing that there is a dependence on the ultraviolet light. It has been found that there is a correlation between the fetomaternal serum levels of 1,25 (OH)2 D3 and 25-OHD. However, there is no correlation between the serum levels of 1,25 (OH)2 D3 and 25-OHD3, neither in the fetus nor in the mother.

Topics: Adult; Calcifediol; Calcitriol; Child; Cholecalciferol; Female; Fetal Blood; Fetus; Humans; Hypophosphatemia, Familial; Infant; Infant, Newborn; Nutritional Requirements; Pregnancy; Rickets; Seasons; Ultraviolet Rays; Vitamin D Deficiency

A rapidly growing understanding of the biochemical and physiological processes that underlie the metabolism of vitamin D has provided new insights into the pathogenesis of oestomalacia. Many of the vitamin D--resistant osteomalacia syndromes can now be explained on the basis of defects in the metabolic conversion of vitamin D to the biologically active dihydroxylated metabolite 1,25(OH)2D and perhaps, in some instances, to impairement of the actions of 1,25(OH)2D on target tissues. The availability of this new information has made possible the synthesis of 1-hydroxylated forms of the vitamin for therapeutic use in states of vitamin D resistance. Although many questions regarding the pathogenesis and most effective approaches in the management of osteomalacia remain unanswered, considerable progress has been made in this direction as a result of continued research on the subject.

Topics: Bone Neoplasms; Chemical Phenomena; Chemistry; Cholecalciferol; Dihydroxycholecalciferols; Ergocalciferols; Giant Cell Tumors; Humans; Hydroxycholecalciferols; Hypoparathyroidism; Hypophosphatemia, Familial; Kidney Failure, Chronic; Metabolism, Inborn Errors; Nephrectomy; Osteomalacia; Phosphates; Pseudohypoparathyroidism; Vitamin D; Vitamin D Deficiency

Topics: Bone and Bones; Bone Diseases; Calcium; Cholecalciferol; Chronic Kidney Disease-Mineral and Bone Disorder; Humans; Hydroxycholecalciferols; Hypoparathyroidism; Hypophosphatemia, Familial; Kidney; Liver Cirrhosis; Parathyroid Hormone; Phosphates; Protein Precursors; Pseudohypoparathyroidism; Vitamin D

Topics: Adrenal Cortex Hormones; Animals; Anticonvulsants; Bone and Bones; Calcium; Carrier Proteins; Cholecalciferol; Dihydroxycholecalciferols; Humans; Hydroxycholecalciferols; Hypocalcemia; Hypoparathyroidism; Hypophosphatemia, Familial; Intestinal Absorption; Kidney; Kidney Failure, Chronic; Kidney Tubules; Liver; Mixed Function Oxygenases; Parathyroid Hormone; Phosphorus; Vitamin D; Vitamin D Deficiency

Extensive experimental evidence has established a significant role of calciferol in the maintenance of normal calcium homeostasis. Present knowledge indicates that vitamin D(3) must first be converted to 25-OH-D(3) and then to 1,25(OH)(2)D(3), the most active known form of the steroid. Many of the factors regulating the rate of production of this last steroid from its precurser have been evaluated, and the concept that vitamin D functions as a steroid hormone seems to be well established. Deranged action of calciferol, caused by impaired metabolism of the steroid or through altered sensitivity of target tissues, may be involved in the pathophysiology of several disease states with abnormal calcium metabolism. It is noted that liver disease, osteomalacia due to anticonvulsant therapy, chronic renal failure, hypophosphatemic rickets, hypoparathyroidism, hyperparathyroidism, sarcoidosis and idiopathic hypercalciuria have possible relation to alterations in metabolism or action of vitamin D. The future clinical availability of 1,25(OH)(2)D(3) and other analogs of this steroid may offer potential therapeutic benefit in the treatment of certain of the disease entities discussed.

Topics: Animals; Biological Transport, Active; Bone Resorption; Calcium; Calcium Metabolism Disorders; Cholecalciferol; Collagen; Homeostasis; Humans; Hydroxycholecalciferols; Hyperparathyroidism; Hypoparathyroidism; Hypophosphatemia, Familial; Intestinal Absorption; Kidney; Kidney Diseases; Liver; Liver Diseases; Sarcoidosis; Skin; Ultraviolet Rays; Vitamin D; Vitamin D Deficiency

Topics: Animals; Cholecalciferol; Chronic Kidney Disease-Mineral and Bone Disorder; Dihydrotachysterol; Dihydroxycholecalciferols; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Rats; Rickets; Vitamin D; Vitamin D Deficiency

Topics: Anticonvulsants; Bone and Bones; Bone Diseases; Calcium; Cell Membrane Permeability; Cholecalciferol; Cholesterol; Ergocalciferols; Gastrointestinal Diseases; Humans; Hypoparathyroidism; Hypophosphatemia, Familial; Intestinal Mucosa; Kidney; Kidney Failure, Chronic; Parathyroid Hormone; Sarcoidosis; Skin; Vitamin D

Topics: Aortic Valve Stenosis; Calcium; Calcium Metabolism Disorders; Cholecalciferol; Ergocalciferols; Female; Humans; Hydroxycholecalciferols; Hypercalcemia; Hypophosphatemia, Familial; Infant; Kidney; Nutritional Requirements; Pregnancy; Skin; Vitamin D; Vitamin D Deficiency

X-linked hypophosphatemic rickets (XLHR) is frequently associated with growth retardation and short adult stature, even with an appropriate conventional treatment associating phosphate and calcitriol or 1 alpha-hydroxyvitamin D. Its pathogenesis is unclear; growth hormone (GH) secretion is usually normal. Six children with XLHR and growth retardation were treated with GH during 6 years. In addition, they received the conventional treatment. At the beginning of the treatment mean age was 7.8 +/- 1.8 years, and height mean Z score was -3.4 +/- 0.5. A control group was composed of six children with XLHR (age: 7.9 +/- 2.5 years) receiving the conventional treatment only. Under GH treatment statural growth was improved, with significant increase in Z score and predicted adult height; the height gain was significantly higher in the GH treated group as compared with the group receiving the conventional treatment only. In addition, radial bone mineral density increased significantly under GH treatment. GH treatment thus appears to be a useful treatment to improve statural growth in children with XLHR.

Topics: Adult; Body Height; Bone Density; Calcitriol; Child; Cholecalciferol; Drug Therapy, Combination; Female; Follow-Up Studies; Growth Disorders; Growth Hormone; Humans; Hypophosphatemia, Familial; Male; Phosphates; Treatment Outcome

The effects of 25-hydroxycholecalciferol were studied in 4 children with deficiency rickets and 22 children with D-resistant rickets, including patients with hereditary hypophosphatemic D-resistant rickets, "pseudo-deficiency" rickets, and rickets secondary to cystinosis or to tyrosinosis. Three protocols were used. (a) 8 days after a single oral dose of 16,000 IU of 25-hydroxycholecalciferol, normalization of all biological parameters was observed in all cases of deficiency rickets. A complete lack of response was observed in the different types of resistant rickets. (b) Under prolonged administration of 2,640 IU/day for 2 months, clinical-biological symptoms and X-ray lesions disappeared, and a catch-up growth pattern was observed in deficiency rickets; no relapse of rickets occurred up to 5 months after therapy was stopped. The same dose had no significant effect in 10 patients with hereditary hypophosphatemic D-resistant rickets. A bone biopsy performed in one case showed the persistence of characteristic lesions. (c) With increasing doses of 25-hydroxycholecalciferol varying from 6,000 to 30,000 IU/day and a follow-up of 6 months up to 2 yr duration, clinical-biological-radiologic recovery and catch-up growht was obtained in all cases of "pseudo-deficiency" rickets. In hypophosphatemic hereditary D-resistant rickets, 5 out of 13 patients' serum concentration of phosphorus reached at least 30 mg/liter, but a catch-up growth pattern was not observed. These results indicate that (a) 25-hydroxycholecalciferol is highly active in deficiency rickets; (b) a defect in the conversion of vitamin D(3) to its active 25-hydroxy metabolite is probably not the metabolic defect in any of the different types of vitamin D-resistant rickets studied.

Topics: Administration, Oral; Alkaline Phosphatase; Amino Acid Metabolism, Inborn Errors; Bone and Bones; Calcium; Child, Preschool; Cholecalciferol; Citrates; Clinical Trials as Topic; Cystinosis; Drug Resistance; Evaluation Studies as Topic; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Infant; Magnesium; Microradiography; Phosphorus; Rickets; Tyrosine

Inactivating mutations of the PHEX (phosphate-regulating gene with homologies to endopeptidases on the X chromosome) endopeptidase, the disease-causing gene in X-linked hypophosphatemia (XLH), results in increased circulating levels of fibroblastic growth factor-23 (FGF23), a bone-derived phosphaturic factor. To determine the causal role of FGF23 in XLH, we generated a combined Fgf23-deficient enhanced green fluorescent protein (eGFP) reporter and Phex-deficient Hyp mouse model (Fgf23(+/-)/Hyp). eGFP expression was expressed in osteocytes embedded in bone that exhibited marked upregulation of eGFP in response to Phex deficiency and in CD31-positive cells in bone marrow venules that expressed low eGFP levels independently of Phex. In bone marrow stromal cells (BMSCs) derived from Fgf23(-/-)/Hyp mice, eGFP expression was also selectively increased in osteocyte-like cells within mineralization nodules and detected in low levels in CD31-positive cells. Surprisingly, eGFP expression was not increased in cell surface osteoblasts, indicating that Phex deficiency is necessary but not sufficient for increased Fgf23 expression in the osteoblast lineage. Additional factors, associated with either osteocyte differentiation and/or extracellular matrix, are necessary for Phex deficiency to stimulate Fgf23 gene transcription in bone. Regardless, the deletion of Fgf23 from Hyp mice reversed the hypophosphatemia, abnormal 1,25(OH)(2)D(3) levels, rickets, and osteomalacia associated with Phex deficiency. These results suggest that Fgf23 acts downstream of Phex to cause both the renal and bone phenotypes in Hyp mice.

Topics: Animals; Body Weight; Bone Density; Bone Marrow Cells; Calcium; Cholecalciferol; Disease Models, Animal; Female; Femur; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Gene Expression Regulation; Green Fluorescent Proteins; Hypophosphatemia, Familial; Male; Membrane Glycoproteins; Metalloendopeptidases; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Fluorescence; Osteocytes; Parathyroid Hormone; PHEX Phosphate Regulating Neutral Endopeptidase; Phosphorus; Promoter Regions, Genetic

In 20 children with tibial and femoral bones deformities due to hypophosphatemic rickets a corrective osteotomy/osteoclasis at 2 or 4 sites was performed. Both preoperative and postoperative pharmacological treatment was introduced. Good results were achieved in 13 cases, satisfactory an 4 and bad in 3 cases.

Topics: Adolescent; Chemotherapy, Adjuvant; Child; Child, Preschool; Cholecalciferol; Female; Humans; Hypophosphatemia, Familial; Male; Osteotomy; Phosphates; Treatment Outcome

The effects of different treatment regimens and the influence of parental height on the statural growth of 40 patients with hereditary vitamin D-resistant hypophosphatemic rickets were investigated. Three treatment regimens, each with oral phosphate, were used: vitamin D (0.5 to 2 mg/day), calcidiol (50 to 200 micrograms/day), and 1 alpha-hydroxyvitamin D3 (1 to 3 micrograms/day). Mean duration of follow-up was 9.5 +/- 5.1 years. The results show that (1) there was no acceleration of growth before puberty for the majority of children treated with vitamin D (12/16) or calcidiol (13/15), whereas 1 alpha-hydroxyvitamin D3 promoted catch-up growth in 10 of 16 patients; (2) height gain during puberty was normal, irrespective of the treatment; (3) most vitamin D-treated male and female subjects and calcidiol-treated male subjects had short adult stature, but the majority (75%) of the 1 alpha-hydroxyvitamin D3-treated groups had normal stature; (4) parental stature had little influence on the adult height of male subjects, but that of affected girls was positively correlated (p less than 0.002) with mid-parental height. These results demonstrate that 1 alpha-hydroxyvitamin D3 is superior to vitamin D or calcidiol for improvement of stature of patients with hypophosphatemic vitamin D-resistant rickets, and indicate the importance of parental height in determining the adult height of affected girls.

Topics: Body Height; Child, Preschool; Cholecalciferol; Ergocalciferols; Female; Growth; Humans; Hypercalcemia; Hypophosphatemia, Familial; Male; Parathyroid Hormone; Parents; Phosphates; Phosphorus; Puberty; Retrospective Studies; Vitamin D

We report a rare case of Albright's syndrome associated with both a soft-tissue myxoma and hypophosphataemic osteomalacia. Renal tubular function was preserved, except for glycosuria. Serum levels of 1,25(OH)2 vitamin D3 were normal. Excision of the myxoma did not influence the biochemical abnormalities, nor did standard doses of vitamin D3 or 1 alpha-OH vitamin D3. The previously reported cases of hypophosphataemic osteomalacia associated with fibrous dysplasia and mesenchymal tumours are reviewed and the underlying mechanism discussed.

Topics: Cholecalciferol; Female; Fibrous Dysplasia of Bone; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Middle Aged; Myxoma; Osteomalacia; Soft Tissue Neoplasms; Syndrome

The clinical course of a 9-month-old boy with Vit. D resistant rickets receiving treatment course 1-Alpha-hydroxycholecalciferol is described. Patient's response to therapy was excellent, after regression of bone changes and normalization of serum parameters drug treatment was discontinued for differential diagnostic considerations. Even several months later no relapse occurred. Due to this fact and the high concentration of serum 1,25-dihydroxycholecalciferol concentration during therapy the very rare pseudovitamin-D-deficiency type II, which is characterized by a bone receptor defect, was assumed. In contrast, successful treatment with low-dose 1 Alpha-OHCCF indicates that the underlying defect is pseudovitamin-D-deficiency rickets type I, however this form would require lifelong therapy. The differential diagnosis based on recent knowledge of Vitamin-D-metabolism is discussed.

Topics: Calcifediol; Cholecalciferol; Diagnosis, Differential; Dose-Response Relationship, Drug; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Infant; Male; Vitamin D Deficiency

A half century ago, vitamin D was recognized as a vitamin. Now it has become clear that it is also a hormone--indeed the biochemical cornerstone of a major hormonal system involved in regulating the body's calcium economy. The active metabolite, calcitriol, produced in the kidney, acts on bone and intestine and has been found effective in therapy of osteodystrophy and perhaps other metabolic bone diseases.

Topics: Calcium; Cholecalciferol; Chronic Kidney Disease-Mineral and Bone Disorder; Humans; Hypoparathyroidism; Hypophosphatemia, Familial; Osteoporosis; Phosphates; Phosphorus; Vitamin D

Topics: Adult; Calcifediol; Child; Cholecalciferol; Gas Chromatography-Mass Spectrometry; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Reference Values

Failure to diagnose and treat hypophosphatemic rickets during childhood resulted in stunted growth and progressive deformities of the lower limb. When the deformities were treated surgically, recurrent deformity and non-union of osteotomies developed, and further major opeative procedures were required to remedy these complications. Treatment from early childhood with oral phosphate and vitamin D improved the rate of growth and controlled the progression of bowleg deformity. Residual varus deformity was corrected by osteotomy through the proximal tibial metaphysis at skeletal maturity, when the results were predictable. Genu valgum deformity was corrected by stapling the medial part of the distal femoral epiphysis prior to skeletal maturity. With early postoperative mobilization and adequate medication, the complications of delayed tibial union and failure to correct the femoral valgus deformity were avoided.

Topics: Administration, Oral; Adolescent; Adult; Child; Cholecalciferol; Dihydrotachysterol; Female; Growth; Humans; Hypophosphatemia, Familial; Male; Osteotomy; Phosphates

Topics: Adolescent; Age Factors; Child; Cholecalciferol; Female; Humans; Hypophosphatemia, Familial; Male; Prognosis

It is evident that there has been enormous progress within the last decade in our understanding of vitamin D metabolism and its interaction with calcium, phosphate, parathyroid hormone, and a number of other factors. As a result largely of therapeutic trials with various metabolites of vitamin D, we now know something of their probable involvement in the development of rickets and osteomalacia. We do not yet have a clear comprehension of exactly how these metabolites influence bone mineralization other than through their indirect effect on serum calcium and phosphate. Nonetheless it seems likely that at least one, and perhaps more, of the metabolites do exert a more direct effect. One must conclude that a deficiency of the 1alpha-hydroxylase is probably not the only defect in renal insufficiency, although it currently that there must well known. It is premature to go so far as to suggest that there must be another metabolite not being synthesized in the diseased or absent kidney.

Topics: 25-Hydroxyvitamin D3 1-alpha-Hydroxylase; Bone and Bones; Calcification, Physiologic; Calcium; Cholecalciferol; Humans; Hydroxylation; Hypophosphatemia, Familial; Kidney Diseases; Minerals; Osteomalacia; Phosphates; Vitamin D

Topics: Carrier Proteins; Cholecalciferol; Glycoproteins; Humans; Hypoparathyroidism; Hypophosphatemia, Familial; Immunoassay; Polymorphism, Genetic; Rickets

Three siblings, respectively 20, 16 and 12 years old, presented with hypocalcemic vitamin D resistant rickets (Prader's type). Their clinical history included several periods of spontaneous cessation of therapy, with severe relapses. Since 1973, treatment was strictly observed, allowing to test the therapeutic effects of 25 OH D3, 1-25 (OH) 2 D3 and 1-alpha (OH) D3. The clinical effects are reported as well as biochemical data. Among them, an inactive form of hyperparathyroidism is emphasized, which may resemble some cases of pseudohypoparathyroidism. Simultaneous resistance to exogenous PTE was also demonstraded.

Topics: Adolescent; Adult; Child; Cholecalciferol; Drug Evaluation; Ergocalciferols; Female; Follow-Up Studies; Humans; Hypophosphatemia, Familial; Male; Vitamin D

Topics: Calcium; Child; Cholecalciferol; Chromosome Aberrations; Chromosome Disorders; Ergocalciferols; Female; Humans; Hypocalcemia; Hypophosphatemia, Familial; Infant; Intestinal Absorption; Male; Phosphates; Rickets; Vitamin D; Vitamin D Deficiency

Topics: Calcium; Child; Cholecalciferol; Diagnosis, Differential; Humans; Hypophosphatemia, Familial; Phosphates; Sex Chromosome Aberrations; Vitamin D

Topics: Adolescent; Child; Child, Preschool; Cholecalciferol; Female; Fibrous Dysplasia of Bone; Fibrous Dysplasia, Polyostotic; Humans; Hypophosphatemia, Familial; Phosphates

Topics: Anticonvulsants; Cholecalciferol; Dihydrotachysterol; Dihydroxycholecalciferols; Ergocalciferols; Genes, Dominant; Genes, Recessive; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Rickets; Sex Chromosomes; Vitamin D

Topics: Adenosine Triphosphatases; Amino Acids; Child, Preschool; Cholecalciferol; Fanconi Syndrome; Humans; Hypophosphatemia, Familial; Infant; Kidney Diseases; Kidney Tubules; Magnesium; Magnesium Deficiency; Male; Phosphorus; Potassium

Topics: Chemical Phenomena; Chemistry; Cholecalciferol; Humans; Hypophosphatemia, Familial; Infant; Infant, Newborn; Rickets; Vitamin D

Topics: Child; Child, Preschool; Cholecalciferol; Dihydroxycholecalciferols; Ergocalciferols; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Injections, Intravenous; Steroid Hydroxylases; Time Factors; Vitamin D

Topics: Animals; Calcium; Cholecalciferol; Diet; Hypocalcemia; Hypophosphatemia, Familial; Inositol; Male; Nutritional Requirements; Osteomalacia; Rats; Spectrophotometry, Atomic

Topics: Adult; Alkaline Phosphatase; Calcium; Child; Cholecalciferol; Dihydrotachysterol; Humans; Hydroxycholecalciferols; Hydroxyproline; Hypophosphatemia, Familial; Male; Phosphorus

Topics: Child; Cholecalciferol; Feces; Female; Humans; Hydroxycholecalciferols; Hypophosphatemia, Familial; Intestinal Absorption; Male; Rickets; Time Factors; Tritium

Topics: Adult; Alkaline Phosphatase; Body Height; Body Weight; Calcium; Child, Preschool; Cholecalciferol; Ergocalciferols; Female; Humans; Hydroxyproline; Hypophosphatemia, Familial; Male; Osteomalacia; Phosphates; Phosphorus; Radiography; Wrist

Topics: Cholecalciferol; Deficiency Diseases; Female; Humans; Hypocalcemia; Hypophosphatemia, Familial; Infant; Male; Parathyroid Hormone; Vitamin D

Dietary strontium inhibits both the synthesis of 1,25-dihydroxycholecalciferol and intestinal calcium absorption in vitamin D(3)-repleted chicks. 1,25-Dihydroxycholecalciferol restores calcium absorption to normal, while 25-hydroxycholecalciferol is without effect in the strontium-fed chick. It is suggested that strontium induces rickets by blocking the biosynthesis of 1,25-dihydroxycholecalciferol, the metabolically active form of vitamin D in the intestine.

Topics: Animals; Autoradiography; Calcium; Chickens; Cholecalciferol; Hypophosphatemia, Familial; Intestinal Absorption; Rickets; Strontium; Tritium

Topics: Alkaline Phosphatase; Calcium; Child; Cholecalciferol; Feces; Female; Humans; Hypophosphatemia, Familial; Male; Phosphates; Rickets; Vitamin D

Topics: Cholecalciferol; Ergocalciferols; Humans; Hydroxylation; Hypophosphatemia, Familial; Kidney Tubules; Vitamin D

Topics: Cholecalciferol; Female; Humans; Hypophosphatemia, Familial; Protein Binding; Rickets; Tritium

Topics: Adolescent; Adult; Child, Preschool; Cholecalciferol; Growth; Humans; Hypophosphatemia, Familial; Infant; Rickets

Topics: Adolescent; Adult; Cholecalciferol; Female; Humans; Hypophosphatemia, Familial; Male; Rickets; Tritium

The fate of an intravenous dose of tritiated vitamin D(3) was studied in seven normal subjects, four children with vitamin D-resistant rickets, and four adults with a familial history of vitamin D-resistant rickets and persistent hypophosphatemia. An abnormal metabolism of vitamin D in vitamin D-resistant rickets was defined and characterized by a decrease in the plasma fractional turnover rate, a marked increase in plasma water-soluble metabolites, and a relative decrease in the conversion of vitamin D to a polar, biologically active metabolite. Alterations in vitamin D metabolism in the adults with persistent hypophosphatemia were similar but less severe than those of affected children with vitamin D-resistant rickets. It is tentatively concluded that the abnormalities in vitamin D metabolism documented in patients with vitamin D-resistant rickets and familial hypophosphatemia may account for the observed osseous and biochemical changes.

Topics: Adolescent; Adult; Alkaline Phosphatase; Calcium; Child; Cholecalciferol; Chromatography; Chromatography, Gel; Chromatography, Thin Layer; Feces; Female; Humans; Hypophosphatemia, Familial; Male; Phosphorus; Rickets; Tritium