vitamin-d-2 and Kidney-Calculi

Despite the important role of vitamin D in maintaining bone health, many clinicians are reluctant to treat vitamin D deficiency in kidney stone formers because of the theoretical risk of increasing urinary calcium excretion. This study examined the effect of vitamin D repletion on urinary calcium excretion among stone formers.. Participants (n=29) were recruited from urology clinics affiliated with New York Presbyterian Hospital. Enrollment criteria included a history of nephrolithiasis, urinary calcium excretion between 150 and 400 mg/d, and a serum 25-hydroxyvitamin D level <30 ng/ml. Participants were given oral ergocalciferol (50,000 IU/wk) for 8 weeks. Serum and 24-hour urine tests were repeated after 8 weeks.. Levels of 25-hydroxyvitamin D increased significantly after vitamin D repletion (17±6 and 35±10 ng/ml, P<0.001), but mean 24-hour urinary calcium excretion did not change (257±54 and 255±88 mg/d at baseline and follow-up, respectively, P=0.91). However, 11 participants had an increase in urinary calcium excretion ≥20 mg/d; these participants also had an increase in urine sodium excretion, likely reflecting dietary variability. No participant experienced adverse effects from vitamin D, including hypercalcemia.. Among stone formers with vitamin D deficiency, a limited course of vitamin D repletion does not seem to increase mean urinary calcium excretion, although a subset of individuals may have an increase. These data suggest that vitamin D therapy, if indicated, should not be withheld solely on the basis of stone disease, but 24-hour urinary calcium excretion should be monitored after repletion.

Topics: Adult; Calcium; Ergocalciferols; Female; Humans; Kidney Calculi; Linear Models; Male; Middle Aged; Multivariate Analysis; Parathyroid Hormone; Sodium; Statistics, Nonparametric; Vitamin D; Vitamin D Deficiency; Vitamins

Options for chronic treatment of hypoparathyroidism include calcitriol, recombinant human parathyroid hormone, and high-dose vitamin D (D2). D2 is used in a minority of patients because of fear of prolonged hypercalcemia and renal toxicity. There is a paucity of recent data about D2 use in hypoparathyroidism.. Compare renal function, hypercalcemia, and hypocalcemia in patients with hypoparathyroidism treated chronically with either D2 (D2 group) or calcitriol.. A retrospective study of patients with hypoparathyroidism treated at the University of Maryland Hospital. Participants were identified by a billing record search with diagnosis confirmed by chart review. Thirty patients were identified; 16 were treated chronically with D2, 14 with calcitriol. Data were extracted from medical records.. Serum creatinine and calcium, hospitalizations, and emergency department (ED) visits for hypercalcemia and hypocalcemia.. D2 and calcitriol groups were similar in age (58.9 ± 16.7 vs 50.9 ± 22.6 years, P = 0.28), sex, and treatment duration (17.8 ± 14.2 vs 8.5 ± 4.4 years, P = 0.076). Hospitalization or ED visits for hypocalcemia occurred in none of the D2 group vs four of 14 in the calcitriol group (P = 0.03); three in the calcitriol group had multiple ED visits. There were no differences between D2 and calcitriol groups in hospitalizations or ED visits for hypercalcemia, serum creatinine or calcium, or kidney stones.. We found less morbidity from hypocalcemia in hypoparathyroid patients treated chronically with D2 compared with calcitriol and found no difference in renal function or morbidity from hypercalcemia. Treatment with D2 should be considered in patients with hypoparathyroidism, particularly in those who experience recurrent hypocalcemia.

Topics: Adult; Aged; Calcitriol; Calcium; Creatinine; Emergency Service, Hospital; Ergocalciferols; Female; Hospitalization; Humans; Hypercalcemia; Hypocalcemia; Hypoparathyroidism; Kidney Calculi; Male; Middle Aged; Nephrocalcinosis; Renal Insufficiency; Retrospective Studies; Vitamins

Topics: Calcium; Ergocalciferols; Female; Homeostasis; Humans; Kidney Calculi; Male

Elevated serum 1,25-dihydroxyvitamin D (1,25(OH)2D) concentrations have been reported among cohorts of recurrent calcium (Ca) kidney stone-formers and implicated in the pathogenesis of hypercalciuria. Variations in Ca and vitamin D metabolism, and excretion of urinary solutes among first-time male and female Ca stone-formers in the community, however, have not been defined.. In a 4-year community-based study we measured serum Ca, phosphorus (P), 25-hydroxyvitamin D (25(OH)D), 1,25(OH)2D, 24,25-dihydroxyvitamin D (24,25(OH)2D), parathyroid hormone (PTH), and fibroblast growth factor-23 (FGF-23) concentrations in first-time Ca stone-formers and age- and gender frequency-matched controls.. Serum Ca and 1,25(OH)2D were increased in Ca stone-formers compared to controls (P = 0.01 and P = 0.001). Stone-formers had a lower serum 24,25(OH)2D/25(OH)D ratio compared to controls (P = 0.008). Serum PTH and FGF-23 concentrations were similar in the groups. Urine Ca excretion was similar in the two groups (P = 0.82). In controls, positive associations between serum 25(OH)D and 24,25(OH)2D, FGF-23 and fractional phosphate excretion, and negative associations between serum Ca and PTH, and FGF-23 and 1,25(OH)2D were observed. In SF associations between FGF-23 and fractional phosphate excretion, and FGF-23 and 1,25(OH)2D, were not observed. 1,25(OH)2D concentrations associated more weakly with FGF-23 in SF compared with C (P <0.05).. Quantitative differences in serum Ca and 1,25(OH)2D and reductions in 24-hydroxylation of vitamin D metabolites are present in first-time SF and might contribute to first-time stone risk.

Topics: Adult; Calcium; Cohort Studies; Ergocalciferols; Female; Fibroblast Growth Factor-23; Homeostasis; Humans; Kidney Calculi; Male; Middle Aged

To present experimental evidence in support of a proposed common cause for absorptive hypercalciuria, renal hypercalciuria, renal phosphate leak and enhancement of 1,25-(OH)2-vitamin D concentrations in patients presenting with renal stone disease; and to suggest further investigation with a view to new management.. An oral calcium loading test was administered to 15 patients with renal stones and 10 normal controls in the fasting state: urine and blood were collected hourly. After the second urine sample, 400 mg calcium dissolved in water was administered orally. Serum calcium, albumin, parathyroid hormone (PTH), and phosphate were measured together with urine calcium clearance and urinary phosphate from which the TmPO4/glomerular filtration rate (GFR) ratio was calculated. Serum 1,25-(OH)2-vitamin D was measured in the first serum sample. In addition, 24 hour urine calcium results were collected retrospectively from the patients' case notes over the previous 18 months.. In the basal state, renal stone patients had an overall greater phosphaturia (lower TmPO4/GFR: median 1.72 compared with 2.10 in controls) and increased calcium clearance. Serum corrected calcium and PTH concentrations did not differ between the groups. After calcium loading, serum calcium and urine calcium clearance rose in both groups, with patients with renal stones experiencing a greater percentage fall in phosphaturia. In both groups TmPO4/GFR fell (greater phosphaturia) with increased serum corrected calcium, with the patients showing notably greater phosphaturia for any given calcium concentration. Patients also had notably greater phosphaturia compared with the serum calcium concentration for any given PTH value. Serum 1,25-(OH)2-vitamin D was higher in patients than controls and for any 1,25-(OH)2-vitamin D concentration phosphaturia measured against serum calcium was greater in patients than controls. 1,25-(OH)2-vitamin D did not correlate with phosphaturia relative to serum calcium concentrations within the patient and control groups.. It is proposed that patients with idiopathic hypercalciuria have an "inappropriately' high phosphate excretion for any given serum calcium concentration. Loss of phosphate may induce increased activation of 1,25-(OH)2-vitamin D. Some of the commonly described causes of stone formation may be manifestations of a single mechanism.

Topics: Adult; Aged; Calcium; Ergocalciferols; Female; Glomerular Filtration Rate; Humans; Kidney Calculi; Kidney Tubules; Male; Middle Aged; Parathyroid Hormone; Phosphates; Regression Analysis; Serum Albumin

A study was undertaken in 46 subjects; 21 patients diagnosed as having HRL and 25 volunteers patients. Biochemical and hormonal analyses were performed in the study population, including determination of Ca, P, Mg, Cr in blood and urine, phosphate tubular resorption (PTR), maximum tubular phosphate resorption (MTPR), fasting calcium secretion (FCS), alkaline phosphatase (AP), hydroxyprolinuria (HPR), osteocalcin (BGP), parathormone (PTH), cAMP, and 1-25(OH)2D. The stone formers showed lower calcemia values (p less than or equal to 0.005d), higher phosphaturia, and magnesiuria (p less than or equal to 0.0005), higher FCS (P less than or equal to 0.005) and higher values for PTH (p less than or equal to 0.01) and cAMP (p less than or equal to 0.0025). No significant differences were observed for the other parameters evaluated. Classification of the patient group into 2 subgroups (renal SbR and absorptive SbA) according to FCS values greater or lower that 0.16 mg/dl, the SbR patient group revealed a higher PTH and 1-25(OH)2D values (p less than or equal to 0.05). There appears to be no increase of bone resorption since AP, HPR, and BGP values in our patients fell within normal ranges. The 1-25(OH)2D levels were also normal and, with respect to the control group, were only elevated for the SbR patient group, whose PTH levels were also observed to be elevated. These increments appear to be related and may result in intermediate forms between renal and absorptive hypercalciuria.

Topics: Adult; Bone Resorption; Calcium; Calcium-Binding Proteins; Cyclic AMP; Ergocalciferols; Female; Humans; Kidney Calculi; Male; Middle Aged; Osteocalcin; Parathyroid Hormone

Two children with X-linked dominant hypophosphatemic rickets treated with vitamin-D metabolites and phosphate supplementation, for prolonged periods, developed hyperparathyroidism with nephrocalcinosis. Calcium infusion tests were performed in both. In one patient, the initial test was done two weeks after all treatment was stopped. Only moderate decrease in the degree of the phosphaturia was recorded. However, a repeat test, performed after all medications were withheld for another four weeks, showed normal anti-phosphaturic response, and she continued to be treated conservatively. In the other patient, the test was done five weeks after withholding treatment. Failure to suppress the phosphaturia provided strong support for the diagnosis of tertiary hyperparathyroidism. He underwent total parathyroidectomy and the parathyroid histology confirmed the diagnosis. In both, control of parathyroid activity stopped the deterioration in kidney function and improved the response of the basic disorder to treatment. It is concluded that in patients with X-linked dominant hypophosphatemic rickets, the calcium infusion test is useful for the differentiation between secondary-reversible and tertiary-irreversible hyperparathyroidism. To avoid continued stimulation of the parathyroid glands by phosphate administration, we recommend that such calcium infusion test be performed and interpreted after at least six weeks have elapsed without phosphate or vitamin-D administration.

Topics: Adolescent; Calcium; Child; Child, Preschool; Ergocalciferols; Female; Humans; Hyperparathyroidism; Hypophosphatemia, Familial; Kidney Calculi; Male; Parathyroid Glands; Phosphates; Rickets; X Chromosome

An experimental electron-microscopic study of the kidneys was carried out in experimental oxamide nephrolithiasis in rabbits and hypervitaminosis D in rats. The most pronounced changes were revealed in the proximal and the distal convoluted tubules. It is suggested that cytosomes and lysosome-like bodies possibly participated in stone formation and nephrocalcinosis. It is supposed that they played an important role in the morphogenesis of nephrolithiasis man.

Topics: Animals; Ergocalciferols; Kidney; Kidney Calculi; Male; Nephrocalcinosis; Oxalates; Rabbits; Rats

Topics: Aged; Antineoplastic Agents; Bone Neoplasms; Calcinosis; Calcitonin; Cholecalciferol; Cyclophosphamide; Ergocalciferols; Fractures, Spontaneous; Humans; Hypercalcemia; Kidney Calculi; Lung Neoplasms; Male; Neoplasm Metastasis; Osteitis Deformans; Plicamycin; Podophyllin; Quinones; Sarcoma; Vitamin D

A patient with Wilson's disease presented at the age of 41 with a neurological defect and gross osteomalacia secondary to a defect of renal tubular reabsorption. He also showed the unusual features of a renal stone in the presence of the Fanconi syndrome and a relatively low alkaline phosphatase level, possibly due to the additional inherited defect of hypophosphatasia. During four years of treatment with penicillamine and calciferol clinical improvement was spectacular. Details of amino-acid clearances before and after treatment are given, and the results suggest that, as in the brain and the liver, the function of the distal renal tubules may be restored in Wilson's disease when copper is removed.

Topics: Adult; Alkaline Phosphatase; Amino Acids; Ergocalciferols; Fanconi Syndrome; Hepatolenticular Degeneration; Humans; Hypophosphatasia; Kidney; Kidney Calculi; Male; Metabolic Clearance Rate; Neurologic Manifestations; Osteomalacia; Penicillamine; Sex Chromosome Aberrations

Topics: Calculi; Cholestanes; Ergocalciferols; Humans; Kidney; Kidney Calculi; Vitamin D; Vitamins