Active clinical trials for "Vitamin D Deficiency"

This study will evaluate how much vitamin D is present in a mushroom supplement. This supplement contains an extract from mushrooms that have been exposed to sunlight. The mushroom supplement will be compared to non-commercially available vitamin D supplements produced in a Goo Manufacturing Practices (GMP)-licensed facility.

The purpose of this study is to observe changes in iron status and vitamin D status during a 12-24 week supervised training program, specifically males and females between the ages of 30 and 50 years old.

Hypocalcemia is a frequent adverse event after thyroidectomy. It is usually related to hypoparathyroidism, but preoperative hypocalcemia, hypomagnesemia or vitamin D deficiency contributes to it. This study aims to determine the frequency of vitamin D deficiency or insufficiency in patients submitted to thyroidectomy, to define the risk attributed to vitamin D deficiency to postoperative hypocalcemia, to identify other factors associated to postoperative calcium disorder, and to evaluate the benefit of preoperative treatment of vitamin D deficiency to prevent postoperative hypocalcemia.

Recent studies indicate that there is a relationship between cognitive decline and vitamin D deficiency. Up to now, no study has investigated the prevalence of vitamin d deficiency in patient with Alzheimer's disease. Our aim is to investigate the prevalence of vitamin D deficiency and analysis the associated characteristics in patients with Alzheimer's disease.

The aim of this study is to investigate the bioavailability of vitamin D2 and D3 as measured by the increase of the specific hydroxy forms in serum (25(OH)D2 and 25(OH)D3, respectively, and by total 25(OH)D.

Hypothesis: 25-hydroxy vitamin D levels in non-itching hemodialysis (HD) patients will be higher than those in HD patients with itching 25-hydroxy vitamin D levels will be measured in non-itching hemodialysis patients and compared to levels previously measured in a previous study of 25-hydroxy vitamin D levels of patients complaining of itching.

The purpose of this study is to try to correlate vitamin D dosing and dosing adjustment with Vitamin D levels, measure affects of seizure medications on levels as well as pathologic fractures and bone density in severely cognitively impaired, non-mobile children and adolescents with CP.

Hypothesis: Vitamin D supplementation lower renin-angiotensin system activity in obesity. Specific Aim: To investigate whether Vitamin D supplementation in obesity improves the vascular sensitivity to angiotensin II.

Maternal vitamin D deficiency has been suggested to influence fetal and neonatal health. The role of placenta in vitamin D regulation is known but alteration of Vitamin D levels at placental pathologies is unknown. Placental calcification is usually thought to be a physiological aging process. Nevertheless, it can be a pathological change resulting from the effects of environmental factors on the placenta. The aim of the investigators study was to evaluate the relationship between placental calcification and maternal and cord blood 25-hydroxyvitamin-D3 [25(OH)D] and calcium concentrations in low-risk obstetric population at term and their consequences.

The purpose of this study is to investigate whether an association exists between serum vitamin D levels and IVF treatment outcome