Effects of long-term antiepileptic polytherapy on bone biochemical markers in ambulatory children and adolescents and possible benefits of vitamin D supplementation: a prospective interventional study.

PURPOSE: Our aim was to investigate any adverse effects of long-term polytherapy (VPA and add-on-therapy) on bone biochemical markers in ambulatory children and adolescents with epilepsy and the possible benefits of vitamin D supplementation on the same markers. METHODS: In this prospective interventional study, the levels of 25(OH)D and the bone turnover markers of CrossLaps (CTX), total alkaline phosphatase (tALP), osteoprotegerin (OPG), and the receptor activator for nuclear factor kB (RANK) ligand (sRANKL) were determined in forty-two ambulatory children with epilepsy on polytherapy (valproic acid + one or more other from levetiracetam, topiramate, lamotrigine, or rufinamide). The same markers were assessed after a year's supplementation of vitamin D (400 IU/d) and were compared with those of clinically healthy controls. The respective mean (±SD) ages were 11.9 ±â€¯4.6 and 11.4 ±â€¯4.4 yrs. RESULTS: The basal mean 25(OH)D levels in the patients did not differ from controls (23.9 ±â€¯11.5 vs 27.4 ±â€¯13.3 ng/ml), but increased significantly after the vitamin D intake (31.1 ±â€¯13.3 ng/ml, p < 0.01). In parallel, basal serum CTX levels were found to be significantly lower in the patients than controls (0.89 ±â€¯0.63 vs 1.22 ±â€¯0.58 ng/ml, p < 0.02), but not tALP. Osteoprotegerin was higher in the patients (5.7 ±â€¯7.7 pmol/L vs 2.6 ±â€¯1.0 pmol/L, p < 0.03), while sRANKL did not differ. After vitamin D, the CTX levels increased to comparable levels in controls (0.99 ±â€¯0.57 ng/ml), and those of OPG decreased to levels that did not differ from controls (4.9 ±â€¯5.1 pmol/L). The ratio of OPG/sRANKL was higher in patients than controls before treatment (0.030 ±â€¯0.045 vs 0.009 ±â€¯0.005, p < 0.03), but decreased (0.026 ±â€¯0.038) to comparable values in controls later. CONCLUSIONS: These findings imply a lower bone turnover in the young patients on long-term polytherapy (VPA and add-on-therapy), but after one year's vitamin D intake, bone biochemical markers improved.

Use of Vitamin D Bolus in Fortified Juice for Improving Vitamin D Status in Children with Cerebral Palsy.

Children with cerebral palsy (CP) are at risk of poor nutrition due to a number of factors. Feeding, eating, drinking, and swallowing (FEDS) problems are common in these children and may result in protein-calorie malnutrition usually accompanied by micronutrient deficiencies. Vitamin D is among the elements whose uptake is obstructed. Insufficient exposure to solar radiation in children and adolescents with CP adds to further decreasing serum vitamin D levels thus potentially affecting growth, bone density, and muscle function. Since maintaining long-term adherence to daily oral administration of vitamin D in this population is often difficult, bolus therapy by using vitamin D-fortified products could be an alternative way of effective and safe vitamin D intake. PURPOSE: Assessing the efficacy of administration of bolus vitamin D in fortified juice for increasing 25(OH)D levels in a group of 15 children with CP. RESULTS: The juice was well tolerated, and a significant increase in 25(OH)D levels was observed from 54.1 to 110.3 nmol/L (p < 0.0001) 4 weeks after the administration without any case of hypercalcemia. CONCLUSION: Bolus therapy with vitamin D3-fortified juice is well tolerated and effectively increases 25(OH)D levels in children with CP.

Use of Fortified Bread for Addressing Vitamin D Deficiency.

Vitamin D deficiency due to inadequate sun exposure and/or inadequate intake from food is very common worldwide, consisting a major public health problem. As prolonged exposure to ultraviolet radiation involves risks, food fortification of staple foods emerges as a favorable solution for addressing vitamin D deficiency. Bread is a suitable candidate for fortification as it is consumed often and is the main carbohydrate source in European countries.The purpose of this study was the evaluation of the bioavailability of vitamin D from a fortified Greek-type bread that was developed as a means for addressing vitamin D deficiency, by comparing the absorption curve of vitamin D in fortified bread in relation to that of plain vitamin supplementation. Two groups of clinically healthy volunteers consumed 25,000 international units (IU) of vitamin D3 (cholecalciferol) either in fortified bread (Group A) or in a plain supplement form (Group B). The baseline plasma concentrations of cholecalciferol were 8.1 ± 6.0 ng/mL and 6.8 ± 3.4 ng/mL in Groups A and B, respectively. After 12, 24, and 48 h, the concentrations of cholecalciferol in Group A were 16.7 ± 4.8, 15.3 ± 8.3 and 11.9 ± 6.0 ng/mL, respectively, and in Group B, 15.2 ± 3.3, 11.6 ± 2.4, and 9.6 ± 3.6 ng/mL, respectively. In both groups, the concentrations of cholecalciferol at 12 and 24 h were significantly higher than the baseline concentrations (p < 0.01). There were no statistically significant differences between the concentrations of cholecalciferol between Groups A and B, at each time point.Cholecalciferol is bioavailable from Greek-type fortified bread and bread could be used for addressing vitamin D deficiency.

Vitamin D status and cardiometabolic risk factors in Greek adolescents with obesity - the effect of vitamin D supplementation: a pilot study.

INTRODUCTION: Obesity is associated with cardiovascular disease (CVD) risk factors as well as decreased 25(OH) vitamin D serum levels. We aimed to study 25(OH) vitamin D levels in adolescents with obesity compared with normal weight controls in association with CVD risk factors, and the possible effect of vitamin D supplementation. MATERIAL AND METHODS: In a cross-sectional study, 69 obese and 34 normal-weight adolescents were included. In an interventional study 15 adolescents with obesity and vitamin D insufficiency were given 2000 IU vitamin D per os daily for 3 months. RESULTS: Adolescents with obesity had significantly lower 25(OH) vitamin D levels compared with normal-weight controls (12.0 (3.0-36.0) vs. 34.0 (10.0-69.0) ng/ml, respectively, p < 0.001). In adolescents with obesity, 25(OH) vitamin D was inversely associated with leptin even after adjustment for body mass index (BMI) (r = -0.340, p = 0.009). Conversely, 25(OH) vitamin D was not related with other parameters, such as BMI, blood pressure, lipids, glucose, insulin, homeostasis model assessment (HOMA) index, adiponectin, leptin/adiponectin ratio, and visfatin levels. Following supplementation in 15 vitamin D insufficient adolescents with obesity, 25(OH) vitamin D significantly increased (from 17.3 (12.5-27.8) to 32.6 (14.3-68.0) ng/ml, p = 0.005) and so did low-density lipoprotein cholesterol (LDL-C) (from 85.4 ±9.5 to 92.1 ±15.8 mg/dl, p = 0.022), while there were reductions in glycated haemoglobin (HbA1c) (from 5.8 ±0.2 to 5.5 ±0.1%, p = 0.03) and leptin (from 19.7 (7.8-45.5) to 15.1 (4.3-37.3) ng/ml, p = 0.03). Oxidised LDL, paraoxonase, arylesterase, and urine isoprostanes remained unchanged. CONCLUSIONS: Adolescents with obesity had lower 25(OH) vitamin D, which may be associated with higher leptin levels. Vitamin D supplementation may lead to HbA1c and leptin reductions, but also to an increase in LDL-C.

The association between vitamin D status and infectious diseases of the respiratory system in infancy and childhood.

PURPOSE: Respiratory tract infections (RTIs) are a major cause of illness worldwide and the most common cause of hospitalization for pneumonia and bronchiolitis. These two diseases are the leading causes of morbidity and mortality among children under 5 years of age. Vitamin D is believed to have immunomodulatory effects on the innate and adaptive immune systems by modulating the expression of antimicrobial peptides, like cathelicidin, in response to both viral and bacterial stimuli. The aim of this review is to summarize the more recently published data with regard to potential associations of 25-hydroxyvitamin D [25(OH)D] with infectious respiratory tract diseases of childhood and the possible health benefits from vitamin D supplementation. METHODS: The literature search was conducted by using the PubMed, Scopus, and Google Scholar databases, with the following keywords: vitamin D, respiratory tract infection, tuberculosis, influenza, infancy, and childhood. RESULTS: Several studies have identified links between inadequate 25(OH)D concentrations and the development of upper or lower respiratory tract infections in infants and young children. Some of them also suggest that intervention with vitamin D supplements could decrease both child morbidity and mortality from such causes. CONCLUSIONS: Most studies agree in that decreased vitamin D concentrations are prevalent among most infants and children with RTIs. Also, normal to high-serum 25(OH)D appears to have some beneficial influence on the incidence and severity of some, but not all, types of these infections. However, studies with vitamin D supplementation revealed conflicting results as to whether supplementation may be of benefit, and at what doses.

Vitamin D supplementation and bone markers in ambulatory children on long-term valproic acid therapy. A prospective interventional study.

PURPOSE: Our aim was to investigate any adverse effects of long-term valproic acid (VPA) therapy on bone biochemical markers in ambulatory children and adolescents with epilepsy, and the possible benefits of vitamin D supplementation on the same markers. METHODS: In this single center, the prospective interventional study levels of 25-hydroxyvitamin D (25OHD) and the bone turnover indices of Crosslaps (CTX), total alkaline phosphatase (tALP), osteoprotegerin (OPG), and the receptor activator for nuclear factor kB (RANK) ligand (sRANKL) were assessed before and after one year of vitamin D intake (400 IU/d) and were compared with those of clinically healthy controls. Fifty-four ambulatory children with mean (±standard deviation [SD]) age 9.0 ±â€¯4.5 yrs on VPA (200-1200 mg/d) long-term monotherapy (mean: 3.2 ±â€¯2.6 yrs) were studied, before and after a year's vitamin D intake (400 IU/d). RESULTS: Nearly half of the cases were vitamin D insufficient/deficient with mean levels 23.1 ±â€¯12.8 vs 31.8 ±â€¯16.2 ng/mL of controls (p = 0.004) and after the year of vitamin D intake increased to 43.2 ±â€¯21.7 ng/mL (p < 0.0001). In parallel, serum CTX and tALP had a decreasing trend approaching control levels but OPG and sRANKL did not change and were not different from controls. However, after vitamin D intake, a positive correlation was seen between 25OHD and OPG but not before. CONCLUSIONS: The findings imply a higher bone turnover in the young patients on long-term VPA therapy that decreased after vitamin D intake.

Effect of combined vitamin D administration plus dietary intervention on oxidative stress markers in patients with metabolic syndrome: A pilot randomized study.

BACKGROUND: Metabolic syndrome (MetS) patients can have low 25-hydroxyvitamin D 25(OH)VitD levels, which may be associated with increased oxidative stress. There is little data on the effect of 25(OH)VitD administration plus dietary intervention on oxidative stress markers in these patients. AIM: To study the effect of 25(OH)VitD administration plus dietary intervention on oxidative stress markers in MetS patients. METHODS: This is a pre-specified analysis of a previously published study (NCT01237769 ClinicalTrials.gov). MetS participants (n = 50, 52 ± 10 years) were given dietary instructions and were randomized to 25(OH)VitD 2.000 IU/day p.o. (Suppl group) or no supplementation (No-Suppl group). Serum 25(OH)VitD, oxidized LDL (ox-LDL), paraoxonase activity (PON-1), arylesterase activity (ARYL) and urine 8-isoprostane (8-iso-PGF2a) levels were measured at baseline and after 3 months. RESULTS: MetS patients had low baseline 25(OH)VitD levels, which increased by 90% in the Suppl group [from 16.1 (3.3-35.1) to 30.6 (8.4-67.6) ng/mL, p = 0.001] and by 33.3% in the No-Suppl group [from 9.9 (4.0-39.6) to 13.2 (3.5-36.8) ng/mL, p = NS] after intervention. Ox-LDL, PON-1 and ARYL did not change significantly at follow-up in both groups, except for urine 8-iso-PGF2a levels that decreased by 22.7% in the Suppl group [from 48.8 (26.8-137.1) to 37.7 (12.3-99.0) ng/mmol creatinine, p = 0.015] and by 14.4% in No-Suppl group [from 45.8 (16.6-99.3) to 39.2 (13.3-120.1) ng/mmol creatinine, p = NS]. The reduction in 8-iso-PGF2a levels did not differ significantly between the 2 groups. CONCLUSION: The administration of 25(OH)VitD plus dietary intervention in patients with MetS was not associated with meaningful reductions in oxidative stress markers compared with dietary intervention alone.

No effect of vitamin D supplementation on cardiovascular risk factors in subjects with metabolic syndrome: a pilot randomised study.

INTRODUCTION: Patients with metabolic syndrome (MetS) may have lower 25-hydroxyvitamin D (25(OH)VitD) serum levels compared with non-MetS individuals. Vitamin D (VitD) deficiency is associated with various cardiovascular disease (CVD) risk factors. Yet, the effect of VitD supplementation on MetS remains uncertain. Our aim was to examine the effect of VitD supplementation on CVD risk factors in MetS subjects. MATERIAL AND METHODS: This pilot study had a PROBE (prospective, randomised, open-label, blinded end-point) design. Fifty patients with MetS were included and randomised either to dietary instructions (n = 25) (control group) or dietary instructions plus VitD 2000 IU/day (n = 25) (VitD group) for 3 months. This study is registered in ClinicalTrials.gov (NCT01237769). RESULTS: In both groups a similar small weight reduction was achieved. In the VitD group serum 25(OH)VitD levels significantly increased by 91% (from 16.0 (3.0-35.0) to 30.6 (8.4-67.0) ng/ml, p < 0.001), while in the control group no significant change was observed (from 10.0 (4.0-39.6) to 13.0 (3.5-37.0) ng/ml). In both groups triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting glucose, haemoglobin A1c, homeostasis model assessment index and diastolic blood pressure did not significantly change. Systolic blood pressure decreased by 3.7% (from 134 ±14 to 129 ±13 mm Hg, p = 0.05) in the VitD group, while it decreased by 1.5% (from 132 ±13 to 130 ±16 mm Hg, p = NS) in the control group (p = NS between groups). In the VitD group serum 25(OH)VitD increase was negatively correlated with SBP decrease (r = -0.398, p = 0.049). CONCLUSIONS: VitD supplementation (2000 IU/day) did not affect various CVD risk factors in patients with MetS.

The relation of vitamin D status with metabolic syndrome in childhood and adolescence: an update.

Among children and adolescents, metabolic syndrome (MetS) is more common than previously believed. Hence, any information on the relation between vitamin D insufficiency/deficiency and insulin resistance (IR) in this population with risk of developing MetS is of great importance. This review analyzes and evaluates the existing evidence from cross-sectional, observational, and retrospective studies concerning the effect of vitamin D insufficiency/deficiency on MetS as a whole or on its various components. Most data show that insufficient vitamin D status is associated with increased prevalence of MetS or its individual components, mainly blood pressure and IR, often independent of overall obesity or abdominal adiposity. The implications of these findings could be associated with increased risk for developing cardiovascular disease and type 2 diabetes mellitus in later life. The very few randomized control trials examining any possible beneficial effects of vitamin D supplementation are also included.

Vitamin D and stroke: promise for prevention and better outcome.

The role of vitamin D (VitD) has recently been expanded beyond bone homeostasis and regulation of calcium levels. VitD deficiency has been proposed as a new risk factor for cardiovascular disease, including stroke. Low 25(OH)VitD levels are very common among post-stroke patients, probably due to their limited mobility and decreased sunlight exposure along with a higher prevalence of malnutrition, and they have been associated with previous and incident cerebrovascular events. Contributing mechanisms have been linked to the association of VitD deficiency with the presence of hypertension, diabetes mellitus and atherosclerosis. Moreover, there is experimental evidence demonstrating that VitD exerts neuroprotective effects, such as stimulation of neurotrophic factors, quenching of oxidative hyperactivity and regulation of neuronal death, as well as antithrombotic properties. It is plausible that VitD supplementation could be a beneficial intervention for the prevention and/or treatment of cerebrovascular disease possibly by decreasing the aforementioned cerebrovascular risk factors and simultaneously by improving neurologic and cognitive functions, thereby reducing falls and fractures in post-stroke patients. However, study results are still conflicting and data from large, randomized clinical trials are needed to clarify these speculations.

Effect of rosuvastatin monotherapy and in combination with fenofibrate or omega-3 fatty acids on serum vitamin D levels.

BACKGROUND: Low levels of 25(OH) vitamin D [25(OH)VitD] have been recognized as a new cardiovascular disease (CVD) risk factor. Statins seem to increase 25(OH)VitD concentration. AIM: To investigate whether combined treatment with the usual dose of rosuvastatin plus fenofibrate or omega-3 fatty acids would increase 25(OH)VitD levels compared with the high-dose rosuvastatin monotherapy in participants with mixed dislipidemia. METHODS: We randomly allocated 60 patients with mixed dyslipidemia (low-density lipoprotein cholesterol: >160 mg/dL plus triglycerides: >200 mg/dL) to receive rosuvastatin 40 mg (n = 22), rosuvastatin 10 mg plus fenofibrate 200 mg (n = 21), or rosuvastatin 10 mg plus omega-3 fatty acids 2 g (n = 17) daily for 3 months. Our primary end point was changes in the levels of serum 25(OH)VitD. RESULTS: Rosuvastatin monotherapy was associated with a 53% increase in 25(OH)VitD (from 14.6 [1.0-38.0] to 17.8 [5.3-49.6] ng/mL; P = .000). Rosuvastatin plus micronized fenofibrate and rosuvastatin plus omega-3 fatty acids were associated with increases of 64% (from 14.1 [1.0-48.0] to 18.4 [6.7-52.4] ng/mL, P = .001) and 61% (from 10.4 [6.6-38.4] to 14.0 [9.6-37.6] ng/mL, P = .04), respectively. The changes in 25(OH)VitD after treatment were comparable in the 3 groups. CONCLUSION: High-dose rosuvastatin monotherapy and the usual dose of rosuvastatin plus fenofibrate or omega-3 fatty acids are associated with significant and similar increases in the 25(OH)VitD levels. This increase may be relevant in terms of CVD risk prevention.

Novel roles of vitamin D in disease: what is new in 2011?

Vitamin D is a steroid molecule, mainly produced in the skin that regulates the expression of a large number of genes. Until recently its main known role was to control bone metabolism and calcium and phosphorus homeostasis. During the last 2 decades it has been realized that vitamin D deficiency, which is really common worldwide, could be a new risk factor for many chronic diseases, such as the metabolic syndrome and its components, the whole spectrum of cardiovascular diseases, several auto-immune conditions, and many types of cancer as well as all-cause mortality. Except for the great number of epidemiological studies that support the above presumptions, vitamin D receptors (VDRs) have been identified in many tissues and cells. The effect of vitamin D supplementation remains controversial and the need for more persuasive study outcomes is intense.

Inorganic phosphorus homeostasis during the first hour of dialysis.

BACKGROUND/AIM: Hyperphosphatemia is a well-recognized complication of chronic kidney disease, and phosphorus kinetics during hemodialysis (HD) remains a vague area of investigation. We studied the inorganic phosphorus homeostasis during the first hour of an HD session. MATERIALS/METHODS: Twelve patients were studied twice, in two consecutive HD sessions. Total (TPR), extracellular (EPR), and intracellular (IPR) phosphorus mass removal was determined using the direct dialysate quantification (DDQ) method. Alterations of serum inorganic phosphorus (sP), erythrocyte intracellular phosphorus (P(ERY)), and 2,3-diphosphoglycerate (2,3-DPG) concentrations were measured before HD initiation and at 1, 2, 3, 4, 5, 10, 30, and 60 min. RESULTS: The contribution of IPR to TPR was negative in the first 10 min of both HD sessions (-27.2 ± 6.5 and -26.4 ± 58 mmol, respectively, p = ns) while the contribution of the IPR to TPR increased as the time elapsed. Intracellular phosphorus and 2,3-DPG remained almost unchanged during the 60 min of HD session. CONCLUSIONS: Unchanged P(ERY) concentration during the first hour of an HD session does not reject the hypothesis of a simultaneous efflux and influx of phosphorus from/to intracellular compartment.

Breastfeeding and vitamin D status in Greece during the first 6 months of life.

UNLABELLED: Since no foods are vitamin D supplemented in Greece, vitamin D status was assessed in mothers at birth and their infants up to the first 6 months of life, while they were exclusively breast-fed. This was a prospective study. Full-terms (n =35) born during the summer-autumn months and their mothers were assigned to the summer group and the remainder (n =31) to the winter group. One week after birth, serum 25-hydroxyvitamin D (25OHD) was significantly lower in the winter-born than in the summer-born neonates (6.7+/-0.7 vs. 10.1+/-0.9 ng/ml, P <0.01). The respective levels of parathyroid hormone (iPTH) were 64.9+/-13.4 and 33.9+/-4.4 pg/ml (P <0.01). The mothers had serum 25OHD levels of 10.8+/-1.0 ng/ml and iPTH levels of 15.2+/-3.5 pg/ml in the winter and 12.9+/-1.3 ng/ml and 24.8+/-4.8 pg/ml in the summer. During the 6-month follow-up, a steady increase in circulating 25OHD (up to 19.4+/-2.8 ng/ml, P <0.0001) and a decrease in iPTH (to 26.8+/-3.5 pg/ml, P =0.10) were observed in the infants born in the winter. In the summer-born infants, serum 25OHD did not change but iPTH had increased significantly by the 3rd month (59.4+/-21.8, P <0.05). Serum calcium (Ca) increased within normal limits during the study period in both groups. Serum phosphorus (Pi) started higher in the winter group (7.43+/-0.38 vs. 6.27+/-0.23 mg/dl, P <0.01) but thereafter, it was similar in both groups. Total alkaline phosphatase (ALP) increased in both groups during the study (164+/-15 vs. 219+/-17 IU/l, P <0.05 and 189+/-14 vs. 288+/-35 IU/l, P <0.001, respectively). Serum osteocalcin (OC) decreased in the winter-born neonates (32.0+/-3.4 vs. 21.5+/-3.4 ng/ml, P <0.05) and did not change in the summer group (28.9+/-3.5 vs. 26.5+/-2.8 ng/ml). CONCLUSION: Neonates who are breast-fed exclusively during the first 6 months of life are in need of vitamin D supplementation irrespective of the season even in a sunny country like Greece where foods are not supplemented.