Active clinical trials for "Rickets"

Vitamin D deficiency is common worldwide, including in infants and children, and rickets remains a public health concern in many developing countries. The vitamin D status and prevalence of vitamin D deficiency in the Haitian population has not been studied. There is currently no approved point-of-care testing device for vitamin D deficiency. Iodine deficiency and resulting hypothyroidism is the leading cause of preventable neuro-developmental delay and cognitive impairment worldwide. Young infants and children are especially susceptible to sequelae of disruption in thyroid function given the dependence of the developing brain on sufficient levels of thyroid hormone. Perchlorate and thiocyanate have been described as potential environmental disrupters of thyroid function. Lead intoxication is a significant cause of disease throughout the world. Millions of people have suffered the effects of lead poisoning. Although most developed countries have taken drastic measures to limit the environmental lead levels, many countries in the developing world have not been able to address, or even assess, the problem. Our objectives are to study the following three components in 300 Haitian children between 9 months and 6 years of age in three different geographical areas of Haiti: 1) Vitamin D status and prevalence of rickets, environmental factors associated with low vitamin D levels, and the accuracy and efficacy of a vitamin D point-of-care testing (POCT) device for the screening of vitamin D insufficiency. 2) Iodine status and thyroid function, and environmental disruptors such as perchlorate and thiocyanate as potential risk factors for abnormal thyroid function. 3) Lead levels and the extent of childhood lead poisoning.

People with heart failure may have low magnesium and low vitamin D levels. They may also have abnormally high levels of parathyroid hormones. Magnesium and vitamin D are important chemicals that are not routinely measured in blood tests. We are studying how many people with heart failure have low levels of magnesium and vitamin D. We are also studying how many people with heart failure have overactive parathyroid glands and if that is related to their vitamin D levels.

The purpose of this study is to determine if there is correlation between Vitamin D deficiency and spinal disease/spinal fusion surgery.

In this study the investigators wanted to assess vitamin D status and possible consequences of low plasma 25-hydroxyvitamin D levels in a population of healthy mothers and their infants, in the community of Aarhus, Denmark.

This study will encompass an analysis of an eventual association between vitamin D status (maternal during pregnancy, at birth or at 5 years) and hand grip strength at 5 years in children from Odense Child Cohort. Odense Child Cohort is a large-scale, prospective, population-based, follow-up study. Mothers and their children born from January 2010 to December 2012 and resident in the Municipality of Odense, Denmark, are followed from early pregnancy up to adulthood. Data is obtained from questionnaires and medical records and venous blood samples were drawn and stored at a biological bank. Low muscle strength in children has been linked to adiposity, cardiovascular disease and metabolic risk factors and low muscle strength in adolescence has been shown to be a risk factor of early adulthood mortality. There are not many studies on muscle strength in small children. There is some evidence of vitamin D concentrations in the blood having a positive correlation to upper body muscle strength in adolescent girls. Hypovitaminosis D defined as serum 25-hydroxyvitamin D <50nmol/L was evident in 27,8% of the pregnant women and 47,7% of the new-born children in Odense Child Cohort. Animal studies have shown an effect of vitamin D on regulation of muscle function and development. Studies on humans adults have shown that vitamin D deficiency can lead to myopathy. Myopathy in children as a result of hypovitaminosis D is not well-studied. Given the high prevalence of hypovitaminosis D, mild or severe vitamin D-associated myopathy may be prevalent in preschool children. The objectives of this study are 1) to create reference values and determine predictors of hand grip strength at five years, 2) to analyze the associations between vitamin D at different time points and hand grip strength at 5 years.

Fibroblast growth factor 23 (FGF23) is the cornerstone of phosphate / calcium / vitamin D metabolism: it is synthesized mainly by osteocytes and acts as a Phosphating agent, inhibitor of dihydroxyvitamin D, and inhibitor of synthesis and secretion of Parathyroid hormone (PTH) in most tissues. The specific role of FGF23 on bone has yet to be demonstrated. In some diseases such as hypophosphatemic rickets (HR), the direct role of FGF23 on bone has not yet been studied to our knowledge, whereas these genetic hypophosphatemias are secondary to overexpression of FGF23, whether an activating mutation of FGF23 or inhibitory mutations of its inhibitors (Dentin matrix acidic phosphoprotein 1 (DMP1) and Phosphate-regulating neutral endopeptidase, X-linked (PHEX)). However, patients with X-linked hypophosphatemic rickets (XLH) have higher circulating FGF23 levels than healthy controls and these levels are higher in treated patients. Management of XLH consists primarily of correcting the native vitamin D defect by prescribing active vitamin D analogs as well as phosphate supplementation to improve bone mineralization and decrease dental complications, growth, and bone deformities. Recently, a new therapeutic option has been developed for XLH, burosumab, a human monoclonal antibody that binds and inhibits FGF23 activity. The use of burosumab is currently authorized in France in some pediatric patients with severe forms of XLH. Independently of the indirect bone effects of phosphate correction and vitamin D levels, the direct role of burosumab on bone cells has never been studied. The objective of this project is to study the osteoclastic biology of patients with HR compared to control patients, and to evaluate the direct impact of the treatments used in this pathology on human osteoclasts.

This study aims to compare the acute effect of consuming milk and butter fortified with either vitamin D3 or 25 (OH) D3 on serum/plasma vitamin D status in humans. In addition, the effect of vitamin D3 or 25 (OH) D3 in milk and butter on certain CVD risk markers and cognitive function will be examined.

The purpose of the study is to describe vitamin D status among patients with type 2 diabetes and to determine the association between serum 25-hydroxyvitamin D and glycemic control, markers of inflammation and blood pressure

Vitamin D is an essential nutrient. Deficiency of vitamin D is widespread. The prevalence of vitamin D deficiency in early preterm infants is unknown. The American Academy of Pediatrics recommends a daily intake of 400 IU in order to achieve a serum concentration of 20 ng/ml of vitamin D. This recommendation presumes exposure to sunlight, the best source of vitamin D. This study assesses vitamin D status at birth and during hospital stay in infants delivered delivered at earlier than or at 32 weeks gestation. We also assess the adequacy of intake relative to the target set by the American Academy of Pediatrics for children.

To date, the investigators lack characterization of, the burden of, and the systemic progression of disease in ENPP1 deficiency and ABCC6 deficiency from a patient and/or parent perspective. This study aims to document this characterization, progression as well as the burden of disease. Link to the study registration- https://www.engagehealth.com/survey/TakeSurvey.aspx?SurveyID=8252n62