BACKGROUND Even though vitamin D is mainly produced by exposure to sunlight, little is known regarding vitamin D levels in populations living in sub-Arctic areas with little or no daylight during winter. OBJECTIVE We describe distributions of vitamin D3 and the prevalence of adequate levels in a population living above 63 °N. DESIGN We sampled 1,622 randomly selected subjects, aged 25-74 ye...

The vitamin D content of eggs from three retail outlets was measured over five months to examine the effects of production system (organic vs. free range vs. indoor), supermarket and purchase date on the concentration of vitamin D3 and 25-hydroxyvitamin D3. Results demonstrated a higher vitamin D3 concentration in free range (57.2±3.1μg/kg) and organic (57.2±3.2μg/kg) compared with indoor (40.2...

Colorectal cancer (CRC) is one of the leading causes of cancer morbidity and mortality in Western countries. One of the risk factors for colorectal tumorigenesis is vitamin D insufficiency. The aim of this study was to establish whether increasing dietary vitamin D intake can prevent or delay development of chemically induced preneoplastic lesions in the colon of mice. We fed six weeks old fema...

OBJECTIVES To clarify potential differences between denosumab (DNS) and bisphosphonates (BIS) in terms of bone density and bone metabolism, in a sample of postmenopausal women. METHODS A total of 113 postmenopausal women aged 53-66 years were treated with either DNS or BIS for 12 months. Bone densitometry and laboratory tests were compared between baseline and follow-up. RESULTS Femoral nec...

It was confirmed that delta 5,7-sterol delta 7-reductase activity was suppressed by cholecalciferol (vitamin D3) in the enzyme system consisted of microsomes and sterol carrier protein (SCP). The enzyme activity was significantly decreased in the combination with microsomes obtained from either vitamin D-deficient or vitamin D3-treated rat liver and with SCP obtained from vitamin D3-treated rat...

INTRODUCTION Incomplete human extravillous trophoblast (EVT) invasion of the decidua and maternal spiral arteries is characteristic of pre-eclampsia, a condition linked to low maternal vitamin D status. It is hypothesized that dysregulated vitamin D action in uteroplacental tissues disrupts EVT invasion leading to malplacentation. METHODS This study assessed the effects of the active vitamin ...

IITOYO et al. and LAWSON et al. reported that vitamin D3 caused a slight de crease in the activities of Mg-activated DNA-dependent RNA polymerase (1, 2) and Mn++-activated DNA-dependent RNA polymerase (2). However, it is known that calcium inhibits RNA polymerase (3). Since the calcium content of the in testine in vitamin D-treated animals must be higher, the decrease in RNA poly merase activit...

BACKGROUND Vitamin D supplementation is recommended to maintain bone health in the general population and in particular in patients with chronic kidney disease (CKD). While the nutritional status of vitamin D is assessed by circulating levels of 25 (OH) D3, it is not routinely measured to ensure the adequacy of vitamin D supplementation. Current recommendations require the maintenance of serum ...

Pregnancy and lactation are associated with changes in vitamin D and calcium metabolism but the impact of these changes on vitamin D expenditure is unknown. We measured plasma 25(OH)D3 half-life with a stable-isotope tracer and investigated relationships with vitamin D metabolites in pregnant, lactating and 'non-pregnant, non-lactating' (NPNL) women. Vitamin D metabolites, vitamin D binding pro...

The consequences of vitamin D deficiency can be severe. It is therefore recommended that Swiss infants have a minimum intake of 10 μg of vitamin D3 per day during the first 12 mo of life (1). For this purpose they are prescribed an “alcoholic” preparation that contains vitamin D3 (1). Infants given preparations containing vitamin D3 either dissolved in alcohol or in peanut oil very much prefer ...