Serum 25-hydroxyvitamin D3 [25(OH)D3] concentrations are currently recognized as the functional status indicator for vitamin D. Evidence is reviewed that shows that serum 25(OH)D3 concentrations of < 80 nmol/L are associated with reduced calcium absorption, osteoporosis, and increased fracture risk. For typical older individuals, supplemental oral intakes of approximately 1300 IU/d are required...

background: there is a known inverse association between solar radiation and the prevalence of multiple sclerosis (ms). some studies have investigated the link between vitamin d and ms. the aim of this study was to investigate the possible association between serum 25(oh) vitamin d3 concentration and the severity of disease in iranian patients with ms. methods: patients with relapsing-remitting...

OBJECTIVE Decreased serum vitamin D level is a common observation in obese adults. Since no Chinese population-based study has yet evaluated the relationship between serum vitamin D levels and the accurate adiposity variables, this study investigated the association of serum vitamin D (assessed by 25-hydroxyvitamin D3 [25(OH)D3]) levels with precise body fat content and distribution in a cohort...

A novel pathway of vitamin D3 (D3) metabolism, initiated by C20-hydroxylation of D3 by CYP11A1, has been confirmed to operate in vivo. Its major product, 20(OH)D3, exhibits antiproliferative activity in vitro comparable to that of 1,25(OH)2D3, but is noncalcemic in mice and rats. To further characterize the antimelanoma activity of 20(OH)D3, we tested its effect on colony formation of human mel...

OBJECTIVE Evidence from randomised controlled trials suggests that vitamin D may reduce multimorbidity, but very few studies have investigated specific determinants of vitamin D2 and D3 (two isoforms of 25-hydroxyvitamin D). The aim of the study was to investigate the determinants of vitamin D2 and D3 and to identify the risk factors associated with hypovitaminosis D. DESIGN Cross-sectional s...

BACKGROUND Low circulating levels of total vitamin D [25(OH)D] and 25(OH)D3 have been associated with vascular complications in few studies on individuals with type 1 diabetes. However, these measures are affected by UV light exposure. Circulating 25(OH)D2, however, solely represents dietary intake of vitamin D2, but its association with complications of diabetes is currently unknown. We invest...

OBJECTIVE This study aimed to investigate the relationship between serum vitamin D level and carotid intima-media thickness (C-IMT) in Chinese postmenopausal women. METHODS Nine hundred and twenty six Chinese postmenopausal women without carotid artery plaque or history of cardiovascular disease were selected for analysis. Measurements of serum 25 hydroxyvitamin D3 (25(OH)D3) concentration an...

A two-year double-blind study monitored and evaluated the effects of 1a-hydroxy vitamin D3 (1a(OH)D3) on the lumbar (L2.4BMD) and total body bone mineral densities (TBBMD) and occurrence of fracture in 113 female osteoporotic patients receiving 0.75 jig/day of 1a(OH)D3 (n=57) or a placebo (n=56) with calcium supplementation in both groups. L2~BMD increased 1.81% and 2.32% after one and 2 years ...

BACKGROUND Vitamin D is critical for healthy pregnancies and normal fetal development. It is important to accurately ascertain vitamin D status in mothers and their newborns to establish the optimal vitamin D concentration during pregnancy. There are many different metabolites and epimers of vitamin D in peripheral blood and controversy as to the importance of epimers in estimating vitamin D st...

BACKGROUND Considering the suggested link between vitamin D insufficiency and several chronic diseases, attention should be given to approaches for improving vitamin D status. Elderly subjects are regarded as a high-risk group for developing an insufficient vitamin D status. Socioeconomic, dietary, lifestyle and environmental factors are considered as influencing factors, whereupon sex differen...