Vitamin D deficiency is common among kidney transplant (KT) recipients because of reduced sunlight exposure, low intake of vitamin D, the immunosuppressive drug regimen administered, and steroid therapy. Glucocorticoids regulate expression of genes coding for enzymes that catabolize vitamin D, further reducing its level in serum. Although vitamin D primarily regulates calcium homeostasis, vitamin D deficiency is associated with the risk of several diseases, such as diabetes mellitus and tuberculosis. Aim of this review is to highlight endocrine and metabolic alterations due to the vitamin D deficiency by evaluating the mechanisms involved in the development of KT-related disease (cardiovascular, bone mineral density, and new-onset diabetes after transplantation). Next, we review evidence to support a link between low vitamin D status and KT-related diseases. Finally, we briefly highlight strategies for restoring vitamin D status in KT patients.

• Klíčová slova
• Bone mineral density, Cardiovascular disease, Kidney transplantation, Malignancies, New-onset diabetes after transplantation, Vitamin D,
• MeSH
• diabetes mellitus etiologie   MeSH
• kardiovaskulární nemoci etiologie   MeSH
• kostní denzita MeSH
• lidé MeSH
• nedostatek vitaminu D komplikace   farmakoterapie   MeSH
• pooperační komplikace etiologie   MeSH
• transplantace ledvin * MeSH
• vitamin D aplikace a dávkování   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• vitamin D MeSH

OBJECTIVE: This study was designed to evaluate vitamin D status with separate determination of 25-OH D2 and 25-OH D3 and its relationship to vitamin D binding protein (VDBP) in patients with chronic kidney disease (CKD) and long-term haemodialysis patients (HD). METHODS: 45 CKD patients, 103 HD patients, and 25 controls (C) were included. Plasma vitamin D concentrations were determined using chromatography and VDBP in serum and urine in CKD using enzyme immunoassay. RESULTS: Plasma vitamin D levels were lower in CKD (30.16 ± 16.74 ng/mL) and HD (18.85 ± 15.85 ng/mL) versus C (48.72 ± 18.35 ng/mL), P < 0.0001. 25-OH D3 was the dominant form of vitamin D. Serum VDBP was higher in CKD (273.2 ± 93.8 ug/mL) versus C (222 ± 87.6 ug/mL) and HD (213.8 ± 70.9 ug/mL), P = 0.0003. Vitamin D/VDBP ratio was the highest in C and the lowest in HD; however, there was no correlation between vitamin D and VDBP. Urinary concentration of VDBP in CKD (0.25 ± 0.13 ug/mL) correlated with proteinuria (r = 0.43, P = 0.003). CONCLUSIONS: Plasma levels of vitamin D are decreased in CKD patients and especially in HD patients. 25-OH D3 was the major form of vitamin D. Despite urinary losses of VDBP, CKD patients had higher serum VDBP concentrations, indicating compensatory enhanced production. Vitamin D binding protein is not involved in vitamin D deficiency.

• MeSH
• 25-hydroxyvitamin D 2 krev   MeSH
• chronická renální insuficience krev   komplikace   patologie   MeSH
• dospělí MeSH
• kalcifediol krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nedostatek vitaminu D krev   komplikace   patologie   MeSH
• protein vázající vitamin D krev   MeSH
• senioři MeSH
• vitamin D krev   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 25-hydroxyvitamin D 2 MeSH
• kalcifediol MeSH
• protein vázající vitamin D MeSH
• vitamin D MeSH

BACKGROUND: Traditionally, secondary hyperparathyroidism (SHPT) due to low calcitriol synthesis in failing kidneys has been treated with synthetic vitamin D receptor (VDR) activators. Recently, also the importance of low native vitamin D status beyond the issue of SHPT has been recognized in these patients. The aim of this work was to evaluate the effect of cholecalciferol supplementation in haemodialysis patients with low vitamin D serum levels. Another aim was to evaluate dual vitamin D therapy (cholecalciferol supplementation plus paricalcitol) in haemodialysis patients with vitamin D deficiency and concomitant SHPT. METHODS: Ninety clinically stable maintenance haemodialysis patients were included. Supervised cholecalciferol supplementation was administered due to low vitamin D status. Patients with SHPT were also treated with synthetic VDR activator. Two pre hoc subgroups for statistical analysis were formed: patients treated solely with cholecalciferol (N=34; 5,000 IU once weekly) and patients treated with a combination of cholecalciferol (identical dose, i.e. 5,000 IU/week) plus paricalcitol (N=34, median dose 10 μg/week). Follow-up visit was scheduled 15 weeks later. Serum concentrations of calcidiol (25-D), parathyroid hormone (PTH) and beta-cross laps (CTX) were assessed at baseline and at follow-up. Serum calcium, phosphate and alkaline phosphatase (ALP) were monitored monthly. Only non-calcium gastrointestinal phosphate binders were administered. Dialysate calcium was 1.5 mmol/L in all patients, and no oral calcium-containing preparations were prescribed. Depending on data distribution, parametric or nonparametric statistical methods were used for comparison within each group (i.e. baseline vs. follow-up data) as well as between groups. RESULTS: In the whole group of 90 patients, mean baseline 25-D serum level was 20.3 (standard deviation 8.7) nmol/L, and it increased to 66.8 (19) nmol/L (p<0.0001) after supplementation. In both preformed subgroups, the effect of vitamin D supplementation was almost identical. In cholecalciferol monotherapy, 25-D levels increased from 18.4 (8.2) to 68.6 (21.2) and in dual vitamin D therapy from 18.4 (5.0) to 67.6 (17.7) nmol/L (both p<0.0001). In addition, both treatment modalities decreased serum PTH levels importantly: from 21.7 (interquartile range 17.3; 35.4) to 18.1 pmol/L (15.3; 24.7) in monotherapy (p=0.05) and from 38.6 (31.8; 53.3) to 33.9 pmol/L (26.1; 47.5) in dual vitamin D therapy (p=0.01). Serum calcium, phosphate, ALP and CTX did not change. We have not observed any episode of hypercalcemia in any subject during the whole period of follow-up. At baseline, slightly lower 25-D levels were observed in diabetic than in non-diabetic patients. This difference disappeared after substitution. Vitamin D status and its changes were not related to the patient's age. CONCLUSION: Low 25-D levels were very common in haemodialysis patients. They were safely and effectively corrected with supervised low-dose cholecalciferol supplementation. In patients with higher baseline PTH levels, dual vitamin D therapy (cholecalciferol plus paricalcitol) was safely and effectively used.

• MeSH
• alkalická fosfatasa krev   MeSH
• cholekalciferol aplikace a dávkování   MeSH
• chronické selhání ledvin komplikace   terapie   MeSH
• dialýza ledvin MeSH
• ergokalciferoly terapeutické užití   MeSH
• fosfáty krev   MeSH
• inhibitory kostní resorpce terapeutické užití   MeSH
• kalcifediol krev   MeSH
• kombinovaná farmakoterapie MeSH
• lidé středního věku MeSH
• lidé MeSH
• nedostatek vitaminu D krev   komplikace   farmakoterapie   MeSH
• parathormon krev   MeSH
• potravní doplňky MeSH
• receptory kalcitriolu agonisté   MeSH
• sekundární hyperparatyreóza krev   farmakoterapie   MeSH
• senioři MeSH
• vápník krev   MeSH
• vitaminy aplikace a dávkování   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• alkalická fosfatasa MeSH
• cholekalciferol MeSH
• ergokalciferoly MeSH
• fosfáty MeSH
• inhibitory kostní resorpce MeSH
• kalcifediol MeSH
• parathormon MeSH
• paricalcitol MeSH Prohlížeč
• receptory kalcitriolu MeSH
• vápník MeSH
• vitaminy MeSH

Elevated serum parathyroid hormone (PTH) level together with hypocalcemia in chronic kidney disease usually suggests secondary hyperparathyroidism. However, primary hyperparathyroidism should also be considered, especially if concomitant vitamin D deficiency is suspected. We report a case of parathyroid adenoma associated with hypocalcemia and metabolic bone disease in a patient presenting with kidney disorder. The patient was successfully treated by parathyroidectomy that was preceded and followed by intensive calcium and vitamin D supplementation.

• MeSH
• adenom komplikace   chirurgie   MeSH
• hypokalcemie komplikace   MeSH
• lidé MeSH
• nádory příštítného tělíska komplikace   chirurgie   MeSH
• nedostatek vitaminu D komplikace   MeSH
• nemoci ledvin komplikace   MeSH
• paratyreoidektomie MeSH
• primární hyperparatyreóza komplikace   MeSH
• senioři nad 80 let MeSH
• Check Tag
• lidé MeSH
• senioři nad 80 let MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH