Late-onset hypogonadism is defined as a combination of low testosterone (T) levels and typical symptoms and signs. A major area of uncertainty is whether T concentrations are always really sufficient to fully reflect Leydig cell (dys)function. Mild testicular alteration could be diagnosed only by additional biochemical markers, such as luteinizing hormone (LH) and 25-hydroxyvitamin D levels. Th...

OBJECTIVES To evaluate potential differences in plasma 25-hydroxyvitamin in subtypes of age-related macular degeneration (AMD), and in patients in Clinical Age-Related Maculopathy Staging (CARMS) group 5 with or without subretinal fibrosis. METHODS This single-center cross-sectional study included 178 participants during a period of 20 months. Ninety-five patients belonged to CARMS 5; twelve ...

The primary aim was to study the relationship between individual serum levels of 25-hydroxyvitamin D and 4b-hydroxycholesterol, which is an endogenous biomarker of the drug-metabolizing CYP3A enzymes. In addition, the relationship between this biomarker and inflammation, measured as C-reactive protein (CRP), was investigated. Serum samples were used from a recently performed clinical trial in p...

OBJECTIVE To investigate the association between vitamin D status, assessed by plasma 25-hydroxyvitamin D, and risk of incident diabetes. RESEARCH DESIGN AND METHODS Prospective observational study with a mean follow-up of 2.7 years in the Diabetes Prevention Program (DPP), a multicenter trial comparing different strategies for prevention of diabetes in patients with prediabetes. We assessed ...

Vitamin D insufficiency is prevalent in chronic kidney disease (CKD) and associated with secondary hyperparathyroidism (SHPT) and increased risk of bone and vascular disease. Unfortunately, supplementation of stage 3 or 4 CKD patients with currently recommended vitamin D2 or D3 regimens does not reliably restore serum total 25-hydroxyvitamin D to adequacy (≥30ng/mL) or effectively control SHPT....

BACKGROUND Vitamin D is essential for bone health and probably the health of most nonskeletal tissues. Vitamin D deficiency is widespread, and recommended doses are usually inadequate to maintain healthy levels. We conducted a retrospective observational study to determine whether the recommended doses of vitamin D are adequate to correct deficiency and maintain normal levels in a population se...

abstract background: to determine daily calcium, vitamin d intake and serum biochemical findings of rickets in adolescent girls. methods: a total of 414 healthy adolescent student girls aged 11-15 years were evaluated from various areas of tehran, iran with different socioeconomic status. a randomized, cross-sectional, prospective and descriptive study was undertaken for calculation of daily ca...

Background: Serum 25-Hydroxyvitamin D is a biomarker used to assess an individual's vitamin status. Bone health, immune function, calcium and phosphate metabolism crucially regulated by the D. Cardiovascular diseases (CVD) are leading cause of death world widely. Many studies have shown that plays potential role cardiovascular prevention. Study design: It prospective study conducted at Rawal In...