Bone Abstracts

This paper reviews clinical reports of vitamin D deficiency rickets in neonates from 1930 onwards. In 24 reports there was good evidence of maternal deficiency. In some the diagnosis of the rickets led to the identification of symptomatic osteomalacia in the mothers; several had been severe and longstanding. Of the 15 mothers who had assays for serum 25-hydroxyvitamin D (25OHD) 13 had values <25 nmol/l (10 ng/ml) and 10 had values <12.5 nmol/l (5 ng/ml).<p class="a...

Background: A 9-month-old boy was diagnosed with rickets at the age of 6 months. He was born at term in India, following a normal pregnancy. Mother had taken folic acid and calcium, but not vitamin D, as this is the policy for pregnancy vitamins in Kerala.Presenting problems: At 6 months of age he was seen for routine vaccination. The paediatrician noted a prominent forehead and swollen wrists. Wrist x-ray was said to show early rickets. Blood tests show...

Background: Despite the large amount of studies published on the association of vitamin D deficiency with higher incidence of falls and fractures, the threshold for a sufficient serum 25(OH)D concentration remains subject to a considerable debate. There has also been no clear consensus on the assessment and treatment of vitamin D deficiency.Objective: To examine the prevalence of vitamin D deficiency and/or insufficiency and its impact on calcium/phospha...

Background: Despite the large amount of studies published on the association of vitamin D deficiency with higher incidence of falls and fractures, the threshold for a sufficient serum 25(OH)D concentration remains subject to a considerable debate. There has also been no clear consensus on the assessment and treatment of vitamin D deficiency.Objective: To examine the prevalence of vitamin D deficiency and/or insufficiency and its impact on calcium/phospha...

Background: Hypercalcemia in childhood is rare, can be of various origin and might go unrecognized until severe signs appear. We demonstrate hypercalcemia of different causes in two infants.Case no 1.: 5-month old girl with failure to thrive, constipation, muscle hypotonia, dehydration, where total calcaemia peaked to 4.25 mmol/l. Low calcium diet, application of glucocorticoids and furosemide resulted in a drop in calcaemia to values below 3 mmol/l and ...

Background: 1α-hydroxylase is a mitochondrial P450 enzyme critical to the synthesis of active calcitriol from the pro-hormone 25(OH) D. Multiple different mutations in the CYP27B1 gene have been identified that abolish or reduce 1α-hydroxylase enzymatic activity resulting in vitamin D dependent rickets type 1. Children with 1α-hydroxylase deficiency present with a clinical picture of joint pain and deformity, hypotonia, muscle weakness, growth failure and someti...

Objectives: To assess the effects of short-term vitamin D supplementation on bone metabolism, glycaemic status and immune function in vitamin D deficient children.Method: Treatment with daily 5000 IU cholecalciferol supplementation for 6 weeks. At baseline and end of treatment serum 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), serum collagen type 1 cross-linked C-telopeptide (CTX), serum calcium, HbA1c, sex hormon...

Objectives: Murine studies have shown that iron deficiency during pregnancy can cause abnormal phosphate and bone metabolism in offspring by elevating concentrations of fibroblast growth factor-23 (FGF23). FGF23 exists in plasma as an intact phosphate- and vitamin D-regulating hormone and its C-terminal fragment, a cleavage product that possibly antagonises the intact hormone. These findings are pertinent to low-income countries, where the prevalence of iron deficiency in preg...

Objectives: Nutritional rickets results from the interaction of poor vitamin D status and limited calcium intake. Vitamin D requirements are greater in children with limited intake of calcium. We sought to determine the serum 25-hydroxyvitamin D [25(OH)D] concentration that can prevent rickets in calcium-deprived Nigerian children.Methods: We reanalyzed data from a case-control study of Nigerian children with active rickets (cases) and age-, sex-, and we...

Background: Vitamin D status is associated with bone health. Vitamin D deficiency leads to decreased bone formation and increased bone resorption. 25-hydroxyvitamin D (25(OH) D), parathyroid hormone (PTH) levels in children could affect bone turnover, and in turn, the bone markers should reflect vitamin D condition. In children the relationships among 25(OH) D, PTH and bone turnover markers are remain.Objective: To explore the associations among serum 25...