Active clinical trials for "Vitamin D Deficiency"

Vitamin D receptors are present and differently expressed in murine endometrium and ovary throughout the estrous cycle , whereas knock-out experiments have shown that vitamin D receptor null mice experience uterine hypoplasia and impaired folliculogenesis. Only few retrospective studies examining the role of vitamin D levels in infertile patients have been published up to date, whereas results are strongly contradictory, with some supporting that maternal vitamin D deficiency is associated with lower pregnancy rates and others demonstrating that vitamin D deficiency does not affect final reproductive outcome. Finally, a recent retrospective study postulated that vitamin D deficiency may negatively affect pregnancy rates with an effect mediated through the endometrium, given that vitamin D deficiency was not correlated with ovarian stimulation characteristics or with markers of embryo quality in this study. In order to examine a potential negative effect of vitamin D deficiency on pregnancy rates, mediated through the endometrium, the aim of the current study was to examine the impact of vitamin D levels on pregnancy rates only in an infertile population undergoing embryo transfer of frozen-thawed embryos.

The aim of this study is to investigate the bioavailability of conventional and vitamin D fortified fish as measured by the increase of the specific hydroxy form by 25(OH)D3.

The purpose of this study is to assess whether all frail elderly admitted with hip fracture has a vitamin D deficiency, and if s-25(OH)D deficiency increases the risk of hip fracture in frail elderly. Frail elderly are defined as being 65 years of age or older, and living in nursing homes or senior housings. The investigators' hypotheses state that: Frail elderly with hip fractures will have a suboptimal level of vitamin D. Frail elderly with hip fractures are more likely to have a suboptimal level of vitamin D than frail elderly without any hip fractures during the last ten years.

Background: Vitamin D plays a key role in calcium absorption in the gut and in skeletal development. Vitamin D deficiency is common, affecting an estimated one billion people worldwide, including developed countries. Vitamin D deficiency causes rickets, the most common non-communicable disease of childhood. Rickets causes poor growth and skeletal deformities and, at its most severe, seizures and death. Recent data suggest that children with rickets have an increased risk for developing diabetes mellitus. Screening for vitamin D deficiency is not commonly done. It is generally diagnosed only after symptoms of rickets have developed. Prevention and treatment is simple and inexpensive. Hence, early detection of vitamin D deficiency through screening would be beneficial. Studies are urgently needed to validate such screening tests. Calcium balance is tightly regulated in the body and calcium loss in the urine (measured by the urine calcium-to-creatinine ratio) is a sensitive indicator of reduced calcium absorption, such as in vitamin D deficiency. Objective and Hypotheses. The objective of this study is to evaluate the urine calcium-to-creatinine ratio as a noninvasive and inexpensive screening test for vitamin D deficiency. Our hypotheses are 1) that the urine calcium-to-creatinine ratio correlates with blood vitamin D levels in infants and toddlers at risk for vitamin D deficiency and 2) that this test can be used to screen for vitamin D deficiency. Potential Impact. A validated screening tool would allow for the detection of vitamin D deficiency before the development of rickets, decreasing the morbidity and mortality of this common disease.

The investigators would like to evaluate the effect of serum 25-hydroxy vitamin D level on post-operative short-term functional outcomes after total hip arthroplasty (THA). Hypothesis: Patients with low serum vitamin D level will have less within-patient improvement in pre- to 6 week, 1 year, 2 year and 5 year post THA WOMAC scores, SF-36 scores, and performance-based tests(get up and go test and 2 minute walking test) compared to patients who do not have a low vitamin D levels. Also, Patients with low serum vitamin D level will have a higher rate of postoperative thigh pain or periprosthetic fracture.

Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disorder. It mainly involves the skin, the joints, the nervous system and the kidney and may be life threatening. SLE is associated with production of autoantibodies and perturbations in regulatory T cells and T helper lymphocytes producing interleukin (IL)-17 (Th17 cells). Treatments include corticosteroids, hydroxychloroquine and immunosuppressive agents. Immunomodulatory effects of vitamin D supplementation in VITRO was recently described, notably the expansion of Treg able to suppress inflammatory responses mediated by CD4+ and CD8+ T cells and the decrease of Th17 cells.

This study is intended to address the association between vitamin D status and seroconversion to SARS-CoV-2 in healthy young adults. The primary aim of the study is to determine the rates of 'silent' seroconversion rates, consistent with asymptomatic transmission of SARS-CoV-2, in a young healthy adult population with a wide spread of vitamin D concentrations. The secondary aims of this study are to explore: Any effect of vitamin D status on symptomatic illness. The background 'point' prevalence and subsequent rate of increase in seropositivity for SARS-CoV-2 in healthy young adults. The individual reductions in seropositivity to SARS-CoV-2 over time, and changes in seropositivity in a defined young adult population over time. Where salivary Immunoglobulin A (IgA) may be used to provide an alternative/ complementary serological method The effect (if any) of vitamin D supplementation on seroconversion rates stratified by: i) level of baseline vitamin D 'deficiency/ insufficiency/ sufficiency' status; ii) extent of BMI-defined normal/overweight/obesity cut-offs and iii) gender.

It is known that vitamin D has been found to decrease incidence of viral respiratory infections, as well as have effects on multiple cytokines involved in immunomodulation and the bradykinin/renin-angiotensin system. Recently, data was released showing a correlation between baseline vitamin D deficiency status and increased risk of contracting COVID-19. Separate analysis shows that many of the deleterious effects of COVID-19 may be due to the bradykinin/RAS system, and that vitamin D is one plausible treatment option to modulate these effects. Studies are currently ongoing to determine if vitamin D supplementation of those hospitalized with COVID-19 has a beneficial effect on patient outcomes. Healthcare resources have been strained during the pandemic in areas of heavy caseload. It is possible that those with concurrent vitamin D deficiency and COVID positivity have an increased need for escalation of care. A small study has been conducted in this area, but was limited by small number of subjects.

Background: It remains uncertain whether vitD3 supplementation is beneficial for remission of Crohn's disease (CD). The influence of vitD3 supplementation on Infliximab (IFX) efficacy was retrospectively analyzed in Chinese CD patients. Methods: Patients with moderate-to-severe CD, who were bio-naïve and prescribed with IFX treatment for at least 54 weeks were recorded. VitD3 supplementation was defined as patients additionally took oral vitD3 (125 IU/d) within 3 days after the first infusion and persisted in the whole follow-up period. Disease activity was assessed using Harvey-Bradshaw Index (HBI). Serum cytokine profiles were quantitatively analyzed in a subset of all patients at baseline and 54-week after intervention.

Lack of sleep and poor sleep quality in pregnant women are associated with maternal depression and cognitive-sensual irregularities. These irregularities were reported worsening women's life quality and even increasing suicide ideation. It is also associated with obstetrical complications such as fetal growth deficiency, preterm birth, prolonged labor, preeclampsia and increased abdominal delivery frequency.Vitamin D also may affect the sleep indirectly through the cases with nonspecific pains. It was reported that vitamin D levels are correlated with sleep disorders such as obstructive sleep apnea and restless legs syndrome. The primary purpose of this study is to examine sleep disorders and vitamin D levels in pregnant women, and also, secondarily, vitamin D - anxiety and sleep disorders - anxiety relations were assessed.