Bone Abstracts

Objectives: Mice with a non-functioning vitamin D receptor (VDR mutants) develop severe secondary hyperparathyroidism, which can be rescued by a diet enriched with calcium, phosphate and lactose. In this work, we studied the effects of a low calcium challenge (CD), normal calcium (ND) and a calcium enriched rescue diet (RD) on the bone mineralization density distribution (BMDD) and osteocyte lacunae sections (OLS) in these mice.Methods: BMDD and OLS were...

Background: Zoledronic acid (ZA) is associated with a transient post-infusional acute phase reaction (APR) due to the activation of γδTCR lymphocytes (γδTcells).Aims: To investigate if APR correlates with γδTcell percentage or cytokine polarization, or with 25-OH vitamin D levels; to identify a 25-OH vitamin D level associated with a lower risk of APR.Methods: Sera for ELISA test (IFNγ, IL17, and ...

Maternal vitamin D status has been positively associated with infant bone mass in observational studies. We therefore evaluated whether 1000 IU/day cholecalciferol during pregnancy would lead to greater offspring bone mass at birth, in a UK, multicentre, randomised, double-blind, placebo-controlled trial (MAVIDOS, ISRCTN82927713).At 12 weeks’ gestation, pregnant women with a serum 25-hydroxyvitamin D [25(OH)D] 25-100 nmol/l were randomised to either...

Objectives: AIS is a prevalent three-dimensional spinal deformity associated with low bone mass which has been reported to be a significant prognostic factor for curve progression in AIS. If left untreated, low bone mass in AIS could persist into adulthood thus leading to subsequent health problems. This study aimed at evaluating the therapeutic effect of oral calcium plus Vit-D supplementation for low bone mass in skeletally immature AIS girls.Methods: ...

Tenofovir disoproxil fumarate (TDF) is a critical component of first-line antiretroviral regimens for HIV worldwide. However, TDF-containing regimens have been associated with decreased bone mineral density and increased fracture risk, which may in part be mediated through secondary elevations in parathyroid hormone (PTH). Prior cross-sectional data suggest vitamin D binding protein (DBP) levels may increase with TDF exposure leading to a functional vitamin D deficiency, which...

Osteoporosis has a complex etiology and is considered a multifactorial polygenic disease in which genetic determinants are modulated by hormonal, environmental, and nutritional factors.Polymorphism of the vitamin D receptor gene has been reported to play a major role in variations for genetic regulation of bone mass but its role within various ethnic populations is not clear. Estrogens are known to play an important role in regulating bone homeostasis, t...

Background: Zoledronic acid (ZA) for the treatment of osteoporosis (OP) is associated with a transient post-infusional acute phase reaction (APR) due to ZA-mediated activation of γ-δ TCR lymphocytes (γ-δTCR) and production of cytokines.Primary objective: To investigate if OP patients developing APR (APR+) after ZA infusion have lower 25-OH vitamin D (25-OHvD) levels and a higher percentage of γ-δTCR compared to patients with...

Objectives: X-linked hypophosphataemia (XLH) is a rare, inherited, genetic disease characterised by renal phosphate wasting, bone mineralisation defects, rickets, abnormal tooth development, poor growth and, often, bone pain. Common treatment of children involves supplementation with oral phosphate and active vitamin D (often termed ‘conventional therapy’). The objective of this study was to identify and understand the perceived limitations of conventional therapy fo...

Objectives: Vitamin D has an important effect on bone but there are no trials that directly address the boosting of serum levels of 25-hydroxyvitamin D (25OHD) in bone microarchitecture in Juvenile-onset Systemic Lupus patients (JoSLE). The aim of this study was to evaluate the effect of vitamin D supplementation on bone microarchitecture parameters using HR-pQCT in JoSLE patients.Methods: This study was a randomized double-blind placebo-controlled 24-we...

Although Vitamin D deficiency is the most common form of rickets worldwide, when there is a failure to respond to cholecalciferol, inborn errors of vitamin D metabolism should be considered. We describe two unrelated individuals who presented with early onset rickets characterised by reduced serum levels of 25(OH)D and 1,25(OH)2D, and a deficient response to Vitamin D2/D3 and calcitriol. Case 1: A Caucasian Australian girl with non-consanguineous parents ...