To evaluate vitamin D levels in children treated with fractures during the healing period. A four-year prospective study, including healthy children treated with diaphyseal fracture of femur or forearm bones. Vitamin D levels were examined four times: at the time of the injury and then one, three, and five months after the injury, together with P1NP, ALP, GGT, and parathormone. In the beginning, patients were blindly divided into two groups, one supplemented with vitamin D3 for the entire follow-up period, the other non-supplemented. Altogether, 107 children underwent examination at the time of their injuries. Of these, 63 were included in the study and examined for the entire follow-up period - 36 supplemented, 27 non-supplemented. At the time of injury, 42 % had a deficit of vitamin D, 36.5 % had insufficiency, only 21.5 % had normal levels. In the children supplemented with cholecalciferol, vitamin D levels increased statistically significantly during the follow-up period (already after 1 month), in contrast with non-supplemented patients, where they did not. When we divided patients according to the initial vitamin D levels (deficit/insufficiency/normal levels) or fracture type (femur/forearm), we also observed significantly better results in supplemented groups. We observed a high prevalence of vitamin D deficit or insufficiency in healthy children at the time of their injuries. Patients supplemented with vitamin D3 had normal levels already after one month and this persisted throughout the follow-up period, in contrast with non-supplemented patients. Therefore, we recommend vitamin D testing and administration for children treated for fractures. Keywords: Vitamin D, Pediatric fracture, Children, Vitamin D supplementation.

• MeSH
• cholekalciferol krev   terapeutické užití   MeSH
• dítě MeSH
• fraktury femuru krev   epidemiologie   MeSH
• hojení fraktur * účinky léků   MeSH
• lidé MeSH
• mladiství MeSH
• následné studie MeSH
• nedostatek vitaminu D * krev   epidemiologie   farmakoterapie   MeSH
• potravní doplňky MeSH
• předškolní dítě MeSH
• prospektivní studie MeSH
• vitamin D * krev   terapeutické užití   MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cholekalciferol MeSH
• vitamin D * MeSH

OBJECTIVE: Although calcitriol is essential for bone healing, its serum concentrations are low after hip surgery, and they continue to decline during bone healing. This study aimed to test the hypothesis of an association of changes in calcitriol production with the status of fibroblast growth factor 23 (FGF23) and iron deficiency after elective hip replacement for coxarthrosis. METHODS: In this prospective study, we measured the biomarkers of 17 patients undergoing elective hip replacement on admission, on the first day after surgery, and at the regular check-up after 48 ± 8 days. The serum concentrations of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, transferrin, ferritin, parathyroid hormone, intact plasma FGF23 (iFGF23) and C-terminal FGF23 (cFGF23) were determined. RESULTS: In our patients who underwent elective hip replacement, significant correlations existed between the percent change in the conversion rate of 25(OH)D to 1,25(OH)2D, plasma intact to C-terminal FGF23 ratio, and serum iron. CONCLUSIONS: The production of calcitriol is compromised after elective hip replacement surgery, leading to reduced levels of active vitamin D in the serum. Significant correlations between the percent change in the conversion rate of 25(OH)D to 1,25(OH)2D, plasma intact to C-terminal FGF23 ratio, and serum iron on the first day as well as 7 weeks after surgery could inspire future studies to determine whether and how calcitriol deficiency should be corrected, especially in fracture cases.

• Klíčová slova
• Calcitriol, Elective hip replacement, Fibroblast growth factor 23, Iron, Total 25 hydroxyvitamin D,
• MeSH
• fibroblastové růstové faktory * MeSH
• kalcitriol * MeSH
• lidé MeSH
• parathormon MeSH
• prospektivní studie MeSH
• vitamin D MeSH
• železo MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fibroblastové růstové faktory * MeSH
• kalcitriol * MeSH
• parathormon MeSH
• vitamin D MeSH
• železo MeSH

OBJECTIVE: To assess the decrease in serum calcitriol concentrations after hip fracture. METHODS: Serum concentrations of calcitriol, 25(OH)D, parathyroid hormone (PTH), directly measured free 25(OH)D, and indices of bone formation were measured in elderly patients with hip fracture (HF) and patients with elective hip replacement (EHR) at admission and after 7 weeks. RESULTS: A total of 45 patients with HF and 17 patients with EHR completed this prospective study. Baseline serum calcitriol levels were ≤ 60 pmol/l in 26% of the HF patients. After 7 weeks, they significantly decreased (p < 0.001). In patients with EHR, serum calcitriol was within the reference range in all but one patient and did not change during the 7-week recovery phase. Seven weeks after HF, a significant positive relationship was observed between the change in calcitriol and serum 25(OH)D concentration (r = 0.385, p = 0.009) and free 25(OH)D (r = 0.296, p = 0.048), and a decrease in calcitriol during recovery was associated with a decrease in serum PTH (p = 0.038). Seven weeks after HF, changes in both serum PTH and serum 25(OH)D concentrations contributed to the prediction of changes in serum calcitriol (R2 = 0.190, p = 0.012). CONCLUSIONS: Unlike patients with EHR, subjects with HF had low serum 25(OH)D and low free 25(OH)D concentrations at admission, while their serum 1,25D levels were relatively elevated. Decreases in circulating calcitriol levels in the 7 weeks following hip surgery were associated with a resolution of secondary hyperparathyroidism and low availability of free 25(OH)D.

• Klíčová slova
• Calcitriol, Fracture healing, Free 25 hydroxyvitamin D, Hip fracture, Total 25 hydroxyvitamin D,
• MeSH
• fraktury kyčle krev   MeSH
• hojení fraktur fyziologie   MeSH
• kalcitriol krev   MeSH
• lidé MeSH
• náhrada kyčelního kloubu MeSH
• osteogeneze MeSH
• parathormon krev   MeSH
• prospektivní studie MeSH
• referenční hodnoty MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• vitamin D analogy a deriváty   krev   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 25-hydroxyvitamin D MeSH Prohlížeč
• kalcitriol MeSH
• parathormon MeSH
• vitamin D MeSH

Vitamin D is a micronutrient with pleiotropic effects in humans. Due to sedentary lifestyles and increasing time spent indoors, a growing body of research is revealing that vitamin D deficiency is a global problem. Despite the routine measurement of vitamin D in clinical laboratories and many years of efforts, methods of vitamin D analysis have yet to be standardized and are burdened with significant difficulties. This review summarizes several key analytical and clinical challenges that accompany the current methods for measuring vitamin D. According to an external quality assessment, methods and laboratories still produce a high degree of variability. Structurally similar metabolites are a source of significant interference. Furthermore, there is still no consensus on the normal values of vitamin D in a healthy population. These and other problems discussed herein can be a source of inconsistency in the results of research studies.

• Klíčová slova
• LC–MS/MS, VDR, determination, genomic effects, metabolites, non-genomic effects, vitamin D,
• MeSH
• hodnocení stavu výživy * MeSH
• klinické laboratorní techniky metody   normy   MeSH
• laboratoře normy   MeSH
• lidé MeSH
• nedostatek vitaminu D diagnóza   MeSH
• referenční hodnoty MeSH
• referenční standardy MeSH
• reprodukovatelnost výsledků MeSH
• vitamin D analýza   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• vitamin D MeSH