***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND Intermittent oral or intravenous doses of calcitriol given two or three times per week are commonly used to treat secondary hyperparathyroidism ( secondary HPT ) . This study was undertaken to compare the biochemical and skeletal responses to thrice weekly intraperitoneal ( i.p . ) versus oral doses of calcitriol in children with secondary HPT undergoing peritoneal dialysis ( CCPD ) . METHODS Forty-six patients aged 12.5+/-4.8 years on CCPD for 22+/-25 months were r and omly assigned to treatment with oral ( p.o . ) or i.p . calcitriol for 12 months ; 17 subjects given p.o . calcitriol and 16 subjects given i.p . calcitriol completed the study . Bone biopsies were performed at the beginning and at the end of the study , while determinations of serum and total ionized calcium , phosphorus , alkaline phosphatase , parathyroid hormone ( PTH ) and calcitriol levels were done monthly . RESULTS Serum total and ionized calcium levels were higher in subjects treated with i.p . calcitriol , P < 0.0001 , whereas serum phosphorus levels were higher in those given p.o . calcitriol , P < 0.0001 . For the i.p . group , serum PTH levels decreased from pre-treatment values of 648+/-125 pg/ml to a nadir of 169+/-57 pg/ml after nine months . In contrast , serum PTH levels did not change from baseline values of 670+/-97 pg/ml in subjects given p.o . calcitriol , P < 0.0001 by multiple regression analysis . Serum alkaline phosphatase levels were also lower in patients treated with i.p . calcitriol , P < 0.0001 , but there was no difference between groups in the average dose of calcitriol given thrice weekly . The skeletal lesions of secondary HPT improved in both groups , 33 % of patients developed adynamic bone lesion . CONCLUSION Differences in the bioavailability of calcitriol and /or in phosphorus metabolism may account for the divergent biochemical response to p.o . and i.p . calcitriol BACKGROUND Oral and intravenous calcitriol bolus therapy are both recommended for the treatment of secondary hyperparathyroidism , but it has been cl aim ed that the latter is less likely to induce absorptive hypercalcemia . The present study was undertaken to verify whether intravenous calcitriol actually stimulates intestinal calcium absorption less than oral calcitriol and whether it is superior in suppressing parathyroid hormone ( PTH ) secretion . METHODS Twenty children ( 16 males , age range of 5.1 to 16.9 years , mean creatinine clearance 21.9 + /- 11.5 mL/min/1.73 m2 , range of 7.4 to 52.7 ) with chronic renal failure ( CRF ) and secondary hyperparathyroidism [ median intact PTH ( iPTH ) , 327 pg/mL ; range 143 to 1323 ] received two single calcitriol boli ( 1.5 mg/m2 body surface area ) orally and intravenously using a r and omized crossover design .  iPTH and 1,25(OH)2D3 levels were measured over 72 hours , and intestinal calcium absorption was measured 24 hours after the calcitriol bolus using stable strontium ( Sr ) as a surrogate marker . Baseline control values for Sr absorption were obtained in a separate group of children with CRF of similar severity . RESULTS The peak serum level of 1,25(OH)2D3 and area under the curve baseline to 72 hours ( AUC0 - 72h ) were significantly higher after intravenous ( IV ) calcitriol ( AUC0 - 72h oral , 1399 + /- 979 pg/mL. hour vs. IV 2793 + /- 1102 pg/mL. hour , P < 0.01 ) , but the mean intestinal Sr absorption was not different [ SrAUC0 - 240min during the 4 hours after Sr administration 2867 + /- 1101 FAD% ( fraction of the absorbed dose ) vs. 3117 + /- 1581 FAD% with oral and IV calcitriol , respectively ] . The calcitriol-stimulated Sr absorption was more then 30 % higher compared with control values ( 2165 + /- 176 FAD% ) . A significant decrease in plasma iPTH was noted 12 hours after the administration of the calcitriol bolus , which was maintained for up to 72 hours without any differences regarding the two routes of administration . CONCLUSIONS These results demonstrate that under acute conditions , intravenous and oral calcitriol boli equally stimulate calcium absorption and had a similar efficacy in suppressing PTH secretion Secondary hyperparathyroidism was suppressed over a period of one year in 12 children with chronic renal failure by using a regimen of mild dietary phosphate restriction and high dose phosphate binders . The patients were r and omised to receive either aluminium hydroxide or calcium carbonate by mouth for six months and then crossed over to the other medication . Vitamin D ( dihydrotachysterol ) dosage was unchanged . Serum parathyroid hormone concentrations were reduced to within the normal range , urinary cyclic adenosine monophosphate values fell , plasma phosphate concentrations decreased , and the theoretical renal phosphate threshold increased significantly . Transiliac bone biopsy findings improved in four patients with adequate suppression of parathyroid hormone concentrations , deteriorated in two patients who were not compliant , and did not change in five patients in whom initial bone disease was mild . Growth velocity improved significantly . There was no difference in the clinical response , biochemical changes , or incidence of complications during treatment with the two agents . In view of the risk of aluminium toxicity the use of high dose calcium carbonate with dietary phosphate restriction and vitamin D supplementation is recommended in the control of secondary hyperparathyroidism in children with chronic renal failure Recent studies in adults have suggested that parenteral 1,25-dihydroxyvitamin D3 ( 1,25[OH]2D3 ) may have advantages over oral therapy in the management of renal osteodystrophy . The purpose of this study was to determine whether there were clear differences between oral and IP 1,25(OH)2D3 treatments in children who did not pose a treatment problem . Seven children ( 5 males , 2 females , aged 1.8 to 16 years , median 4.8 years ) undergoing peritoneal dialysis were initially treated with oral 1,25(OH)2D3 for a one month equilibration period They were r and omly assigned to 3 months of either oral or intraperitoneal ( IP ) therapy with 1,25(OH)2D3 followed by 3-months-treatment using the alternative route . No significant differences in serum creatinine , phosphate , or parathyroid hormone concentrations were found between the different routes of administration in the patients . No significant differences in height st and ard deviation scores or renal osteodystrophy scores were found over the six-month study . Paired oral and IP pharmacokinetic studies were performed on these 7 patients and 2 other children who had been treated for at least 2 months using either oral or IP 1,25(OH)2D3 . Serum was taken prior to one of the usual 1,25(OH)2D3 doses and 0.5 , 1.5 , 3 , 6 , and 24 h afterward . The highest measured concentrations of 1,25(OH)2D3 were found at 1.5 h for both oral and IP treatments ( mean Cmax [ SD ] : oral 116 [ 23 ] pmol/l , IP 121 [ 24 ] pmol/l , p > 0.05 ) . The AUC 's for oral and IP therapy were similar ( 1701 [ 276 ] and 1645 [ 301 ] pmol/h/l , respectively ) . In the paired pharmacokinetic studies no significant differences were found between oral and IP treatments for the serum half life ( 27.4 [ 11.6 ] h and 19.2 [ 8.1 ] h , respectively ) and total body clearance ( 15.3 [ 2.1 ] h and 18.4 [ 3.3 ] h , respectively ) of 1,25(OH)2D3 . In children who respond appropriately to oral 1,25(OH)2D3 there is no biological advantage to the use of IP 1,25(OH)2D3 ABSTRACT . Ten children with end stage renal disease on chronic hemofiltration ( HF )  were studied for a 1-yr period to evaluate the efficacy of l,25-dihydroxyvitamin-D3 ( 1,25(OH)2D3 ) therapy on biohumoral parameters of renal osteodystrophy and bone mineral content . In six of these children an acute study was done of the direct effect of the HF procedure on calcium and phosphate balance during 12 HF sessions . During the first 6 months of the study all children were treated with 1,25(OH)2D3 ( 0.25 - 0.50 µg/day ) to maintain plasma calcium at 9.5 - 11.0 mg/dl . There was a significant increase in plasma calcium ( p<0.05 ) and a significant decrease in plasma phosphate ( p<0.01 ) and alkaline phosphatase concentrations ( p<0.05 ) . The circulating levels of NH2 immunoreactive parathyroid hormone did not change , remaining at the upper limits of reference values . Immunoreactive parathyroid hormone- COOH terminal fragment levels decreased significantly ( p<0.05 ) . Bone mineral content rose significantly ( p<0.01 ) . During the last 6 months of the study , to evaluate the possibility that HF alone might control secondary hyperparathyroidism , 1,25(OH)2D3 treatment was discontinued in five children ; plasma calcium and phosphate were well controlled whereas hyperparathyroidism worsened in all five , and one also developed intense pruritus and hypertension . The other five children remained on 1,25(OH)2D3 treatment ; two of these were transplanted , and the other three continued to show an improvement of mineral balance . The results of the acute study showed that calcium balance was positive with a mean Ca++ gain of 140 mg/HF session . The mean total phosphate removed per HF run was 574 mg . We conclude that even though a calcium gain and a high phosphate removal was obtained with our HF prescription , secondary hyperparathyroidism in children on chronic HF may be maintainued under control if 1,25(OH)2D3 supplementation is provided Little is known about the impact of various phosphate binders on the skeletal lesions of secondary hyperparathyroidism ( 2 degrees HPT ) . The effects of calcium carbonate ( CaCO3 ) and sevelamer were compared in pediatric peritoneal dialysis patients with bone biopsy-proven 2 degrees HPT . Twenty-nine patients were r and omly assigned to CaCO3 ( n = 14 ) or sevelamer ( n = 15 ) , concomitant with either intermittent doses of oral calcitriol or doxercalciferol for 8 mo , when bone biopsies were repeated . Serum phosphorus , calcium , parathyroid hormone ( PTH ) , and alkaline phosphatase were measured monthly . The skeletal lesions of 2 degrees HPT improved with both binders , and bone formation rates reached the normal range in approximately 75 % of the patients . Overall , serum phosphorus levels were 5.5 + /- 0.1 and 5.6 + /- 0.3 mg/dl ( NS ) with CaCO3 and sevelamer , respectively . Serum calcium levels and the Ca x P ion product increased with CaCO3 ; in contrast , values remained unchanged with sevelamer ( 9.6 + /- 01 versus 8.9 + /- 0.2 mg/dl ; P < 0.001 , respectively ) . Hypercalcemic episodes ( > 10.2 mg/dl ) occurred more frequently with CaCO3 ( P < 0.01 ) . Baseline PTH levels were 980 + /- 112 and 975 + /- 174 pg/ml ( NS ) ; these values decreased to 369 + /- 92 ( P < 0.01 ) and 562 + /- 164 pg/ml ( P < 0.01 ) in the CaCO3 and the sevelamer groups , respectively ( NS between groups ) . Serum alkaline phosphatase levels also diminished in both groups ( P < 0.01 ) . Thus , treatment with either CaCO3 or sevelamer result ed in equivalent control of the biochemical and skeletal lesions of 2 degrees HPT . Sevelamer , however , maintained serum calcium concentrations closer to the lower end of the normal physiologic range , thereby increasing the safety of treatment with active vitamin D sterols BACKGROUND Prior studies of dialysis practice s and outcomes have included children with varied duration of end-stage renal disease ( ESRD ) . This study evaluated  dialysis characteristics , complications , practice s , and outcomes in an incident pediatric cohort . METHO 
    Output:
    
Vitamin D therapy significantly reduced PTH levels compared with placebo or no treatment .
Bone disease , assessed by changes in PTH levels , is improved by all vitamin D preparations .
However no consistent differences between routes of administration , frequencies of dosing or vitamin D preparations have been demonstrated .
Though fewer episodes of high calcium levels occurred with the non calcium-containing binder , sevelamer , compared with calcium-containing binders , there were no differences in serum phosphorus and calcium overall and phosphorus values were reduced to similar extents .
All RCTs were small with few data available on patient-centred outcomes ( growth , bone deformities ) and limited data on biochemical parameters result ing in considerable imprecision of results thus limiting the applicability to care of children with CKD