Bone Abstracts

Bone is continuously remodeled to remove damage, to adapt to changes in mechanical demands and to regulate calcium homeostasis. The first aim is accomplished by coupled bone formation and resorption whereas adaptation requires sites of formation to differ from those of resorption. The regulation of circulating ions is achieved by a stochastic exchange of bone packets. Here, we investigated these different aspects of remodeling in healthy and ovariectomized (OVX) mice treated w...

Objective: Although obesity is a risk factor for vitamin D insufficiency, its impact on vitamin D-binding protein (DBP) concentration, and thereby possibly also on free 25OHD, is less well known. Our aim was to compare total and free serum 25OHD, and DBP concentrations between obese and normal-weight young adults at baseline, and their responses to cholecalciferol supplementation.Design: A 12 weeks’ randomized, double-blinded clinical trial.<p c...

Vitamin D and its metabolites are bound to vitamin D binding protein (DBP) in the circulation. Only a small proportion is in unbound, free form. According to the ‘free-hormone-hypothesis’ only the free form is biologically active. DBP is a polymorphic protein and different variants of the protein differ in their ability to bind vitamin D. This may have an impact on the amount of free and bioavailable (free+albumin-bound) 25-hydroxyvitamin D (25(OH)D) in the circulati...

Phosphorus intake in western countries is high due to abundant consumption of animal protein and also because of the expanding use of highly absorbable food additive phosphate (FAP) salts in food processing. P is essential for hydroxyapatite in bone, but short-term studies have shown that high P, especially FAP, intake has acute negative effects on bone metabolism. In this study, we investigated the associations between dietary P intake and bone turnover markers by using a cro...

Objectives: Adolescent idiopathic scoliosis (AIS) is a complex three-dimensional spinal deformity associated with low bone mass. Our previous clinical trial demonstrated the anabolic bone effect of vibration treatment (VT) at the femoral neck in AIS subjects. The therapeutic effect was more pronounced in those with optimal serum 25(OH) Vit-D level (>40 nmol/l). To investigate possible factor interaction between Vit-D and VT on their anabolic bone effects, this in-vitro...

Objectives: This study aimed to evaluate detailed bone profiles during puberty for Chinese adolescents in Hong Kong using high-resolution peripheral quantitative computed tomography (HR-pQCT) and dual-energy x-ray absorptiometry (DXA).Methods: 333 healthy girls and 231 healthy boys (12–16-years-old) were recruited from secondary schools. Areal bone mineral density (aBMD) of bilateral femoral necks were measured by DXA while bone quality parameters w...

Objectives: The aim of this study was to evaluate the association between the age at onset of walking and bone mineral content (BMC) in healthy 2-year-old children participating in the Vitamin D in Infants Trial (VIDI).Methods: Altogether 253 children (120 girls, 133 boys) with a daily vitamin D3 intake of 10 μg and a sufficient serum 25-hydroxyvitamin D (25-OHD) concentration (>50 nmol/l) were included in the analysis. BMC was measur...

Objectives: The regulation of fibroblast growth factor 23 (FGF23) metabolism during infancy is inadequately characterized. We previously observed a distinct sex difference in intact FGF23 at 3 months of age. In this study we aimed to further examine the role of sex and iron status in FGF23 metabolism in 1-year-old children.Methods: This was a cross-sectional study including 731 1-year-old Caucasian children participating the Vitamin D intervention in inf...

Background: Besides the classic actions of vitamin D on bone metabolism and calcium homeostasis, there is evidence emphasizing its antiproliferative and proapoptotic activities. Data coming mostly from Northern regions suggest an effect of 25-hydroxyvitamin D (25(OH)D) serum concentrations on breast cancer prevention. We aimed to study the association between 25(OH)D concentrations and breast cancer risk in a Mediterranean population (Spain).Methods: We ...

Objectives: High resolution peripheral quantitative computed tomography (HR-pQCT) was used to evaluate bone quality and volumetric bone mineral density (vBMD). However, manufacturers only provide a standard protocol for adult but not for growing subjects. The aim of this study was to investigate the difference on measurement between two different HR-pQCT scanning protocols in adolescence with unfused growth plate.Methods: 27 boys and 26 girls aged 13&#15...