Bone Abstracts

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 ...

Introduction: Vitamin D is essential for calcium metabolism as well as for fracture prevention. In children, low levels can cause rickets. A high prevalence of inadequacy in children has been reported in many studies. It is entirely prevalent in Lebanese children. There are different ways to detect cut-off points for vitamin D deficiency, The aim of this study was to describe the distribution of serum 25(OH)D levels in Lebanese children, males and females, to evaluate and prop...

Objective: Bone fractures are very common in children and their number is growing every year. Vitamin D has a proven role in the prevention of fractures. In the recent study, we have shown that children with low-energy fractures have significantly lower vitamin D blood levels compared to the children without fractures. Our data indicate that higher levels of vitamin D reduced the risk of fracture by 1.06 times (P<0.0005).Past decade has seen...

Background: The ‘adequate’ level of 25-hydroxyvitamin D (25OHD) in children remains unclear. For bone outcomes, parathyroid hormone (PTH) is an important functional biomarker. Prior studies have shown too weak a correlation between 25OHD and PTH levels to determine adequate 25OHD level.Objective: To determine adequate 25OHD level(s) in children using a normal PTH value of 65 pg/ml while adjusting for calcium intake.Design...

Introduction: Optimal vitamin D intake for lactating women remains controversial. We hypothesized that 1200 IU/day (vs 400 IU/day) of vitamin D during breastfeeding will enhance maternal vitamin D status and bone mass.Methods: Healthy mothers after term, singleton delivery were randomized to receive vitamin D3: 1200 IU/day (800+400 IU/day from multivitamins) or 400 IU/day (placebo+400 IU/day from multivitamins) during lactation. Serum 25-hydroxyvitamin D...

Introduction: Vitamin D deficiency is common among elderly subjects and is associated with reduced muscle strength. Although vitamin D deficiency is common among Saudi subjects, knowledge about its role in relation to muscle strength and physical performance is lacking. The objectives of the present study are to determine vitamin D status in a sample of randomly selected healthy postmenopausal Saudi women and to investigate the association between their serum 25(OH)D levels an...

Vitamin D plays an important role for bone health, and is associated to the risk of osteoporosis development.The aim of the present work was to determine the association between serum vitamin D concentration and the bone mineral density (BMD) in post-menopausal women living in a Mexican rural community (this study was approved by the Institutional Ethics Committee). The BMD was assessed by ultrasound and vitamin D was evaluated using a specific immunoass...

Objectives: Vitamin D dependent rickets type I (VDDR-I) is an autosomal recessive disorder with impaired activation of vitamin D, caused by mutations in CYP27B1. Characteristic clinical features are hypotonia, muscle weakness, growth failure, hypocalcemic seizures in early infancy, and radiographic findings of rickets. We aimed to describe the clinical and laboratory findings in a VDDR-1 case and to report a mutation in CYP27B1.Methods and results: The p...

Background: The baby growing in its mother’s womb needs calcium for skeletal development. Maternal osteoporosis has been attributed to pregnancy in some cases.Presenting problem: A 27-year-old woman in the 7th month of her first pregnancy complained of mid-thoracic back pain after lifting a non-heavy object. The pain remained with differing intensity and was attributed to her pregnancy. After the delivery of a healthy child, the back pain prevented ...

We have previously shown a high prevalence of vitamin D inadequacy (serum 25-hydroxyvitamin D (S25(OH)D) <50 nmol/l) in adolescents (14–18 years) in the UK (51°N)(1). It is well recognised that vitamin D deficiency (S25(OH)D <25 nmol/l) increases the risk of rickets and impaired growth in adolescents, however the optimal vitamin D status for bone health is debated. The aim of this study was to investigate the effects of vitamin D status on bone hea...