BACKGROUND Vitamin D status influences skeletal health, the risk of falls and fractures, and muscle health, and it has been associated with inflammatory, infectious, cardiovascular and metabolic disorders in addition to some cancers. Prevailing intracellular infections such as tuberculosis are speculated to relate to vitamin D status. The vitamin D sources are dietary and dermal, the latter dep...

BACKGROUND Obese adults are frequently vitamin D deficient before bariatric surgery; whether similar abnormalities exist in morbidly obese adolescents is unknown. OBJECTIVE To determine the prevalence of vitamin D deficiency in morbidly obese adolescents. METHODS Cross-sectional study of preoperative laboratory measures from 236 adolescents evaluated for bariatric surgery. RESULTS The gro...

BACKGROUND Residents of nursing homes may have low 25-hydroxyvitamin D (25OHD) concentrations. Associations between vitamin D and cognitive performance, dementia and susceptibility to infections are not clearly established. The aim of this study was to investigate the prevalence of vitamin D deficiency and to identify associated factors among residents of nursing homes for elderly. METHODS In...

Introduction. A role for vitamin D deficiency in Parkinson's disease (PD) has recently been proposed. Given the growing body of evidence for the association of vitamin D with several neurodegenerative disorders and unavailability of any published study in the Middle East, the present study is aimed to determine the associations of circulating 25-hydroxyvitamin D (25OHD) levels with the severity...

Vitamins D(2) and D(3) are generally considered to be equivalent in humans. Nevertheless, physicians commonly report equivocal responses to seemingly large doses of the only high-dose calciferol (vitamin D(2)) available in the U.S. market. The relative potencies of vitamins D(2) and D(3) were evaluated by administering single doses of 50,000 IU of the respective calciferols to 20 healthy male v...

BACKGROUND The association between low levels of 25-hydroxyvitamin D and non-specific musculoskeletal pain, including fibromyalgia syndrome, is controversial. Several studies have reported a "positive association" and two others found "no association." OBJECTIVES To test levels of 25OHD in patients with fibromyalgia syndrome and in matched controls. METHODS The study population comprised 68...

Recently, the reemergence of vitamin D deficiency in developed countries has been pointed out. Vitamin D deficiency is diagnosed based on the serum 25-hydroxyvitamin D (25OHD) level. However, its normal range is still controversial, making the diagnosis of vitamin D deficiency difficult. Here, we present seven Japanese patients diagnosed with vitamin D deficiency. Three patients complained of l...

It is unclear which vitamin D status is optimal for bone health. In this study, we aimed to assess cutoffs of 25-hydroxyvitamin D (25OHD) derived by the literature (20, 25, or 30 ng/mL) in relation to bone turnover and bone mineral density (BMD). Serum 25OHD, PTH, osteocalcin, bone alkaline phosphatase, and C-telopeptide were measured in 274 consecutive postmenopausal women. BMD of the lumbar s...

BACKGROUND Fetuin-A and vitamin D are significant correlates of cardiovascular morbidity in paediatric chronic kidney disease (CKD) patients. It is thus far unknown, whether or not serum fetuin-A is affected by the vitamin D status or treatment with vitamin D preparations in these patients. METHODS In a cross-sectional study, serum concentrations of fetuin-A, 25-hydroxyvitamin D(3) (25OHD) an...

BACKGROUND We aimed to examine associations among serum 25-hydroxyvitamin D (25OHD) levels, 1,25-dihyroxyvitamin D (1,25OHD) levels, vitamin D receptor (VDR) polymorphisms, and renal function based on estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes. METHODS In a cross-sectional study of 410 patients, chronic kidney disease (CKD) stage assessed by eGFR was compared...