Reinhold Vieth

..The implication of all these things for the clinical laboratory is that there will continue to be a demand for 25(OH)D measurements for many years to come...

..The main goal of this study was to examine the vitamin D status and vitamin D intake of young Canadian adults of diverse ancestry during the winter months...

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..It also explains why higher 25(OH)D concentrations are not good if they fluctuate, and that desirable 25(OH)D concentrations are ones that are both high and stable...

..e. a glandular secretory product, having little or no inherent biologic potency, that is converted peripherally to an active hormone...

..For adults, vitamin D intake of 100 mcg (4000 IU)/day is physiologic and safe. The adequate intake (AI) for older adults is 15 mcg (600 IU)/day, but there has been no report focusing on use of this dose...

..The therapeutic implication is that vitamin D supplementation in the range of 2000 IU/d, a dose comparable to the effect of summer, can benefit men monitored for rising PSA...

..This amount of vitamin D results in the optimal function of many aspects of health, including balance and muscle strength that lessen the risk of fracture beyond what is possible via the quality and quantity of bone itself...

..Therefore, advice to avoid UVB light should be accompanied by encouragement to supplement with vitamin D in an amount that will correct for the nutrient deficit that sun-avoidance will cause...

..Older adults are just as efficient in maintaining 25(OH)D, but they need more vitamin D to produce the higher 25(OH)D concentrations required to overcome the hyperparathyroidism associated with their diminishing renal function...

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..The Food and Nutrition Board of the National Academy of Sciences states that 95 microg vitamin D/d is the lowest observed adverse effect level (LOAEL)...

..We asked whether women self-reporting the recommended consumption of vitamin D from milk and multivitamins would be less likely to have low wintertime 25-hydroxyvitamin D (25(OH)D) levels...

..If 70 nmol/L is regarded as a minimum desirable target 25(OH)D concentration, then current recommendations of 15 mcg per day do not meet the criterion of an RDA...

..To examine the prospective associations of baseline vitamin D [25-hydroxyvitamin D; 25(OH)D] with insulin resistance (IR), β-cell function, and glucose homeostasis in subjects at risk for type 2 diabetes...

..However, evidence to date is limited and inconsistent, and few studies have examined associations with nontraditional MetS components...

..0006). The R(2) was 0.29 for the summer model and was 0.21 for the winter model. Overall, there was evidence to suggest that questions designed to assess vitamin D exposure were in fact related to serum 25(OH)D...

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..The 24,25:25VD(3) ratio may therefore have clinical utility as a marker for VD(3) catabolism and a predictor of serum 25VD(3) response to VD(3) supplementation...

..51, 1.22) tumors. This study suggests that vitamin D is associated with a reduced risk of breast cancer regardless of ER/PR status of the tumor. Future studies with a larger number of receptor-negative and mixed tumors are required...

..The active metabolite of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)(2)D], is a potent modulator of immune cells in vitro...

..Some evidence suggests that vitamin D may reduce breast cancer risk. Despite the biological interaction between vitamin D and calcium, few studies have evaluated their joint effects on breast cancer risk...

..We conducted a study to determine whether there is an association between circulating 25-hydroxyvitamin D (25(OH)D) and estradiol and progesterone in young women...

..The fortification process did not alter the yield, chemical composition, or flavor of the Cheddar cheese. We conclude that industrially manufactured Cheddar and low-fat cheeses are suitable for vitamin D3 fortification...

..To characterize the effect of vitamin D(3) intake on urinary calcium:creatinine ratios across predefined ranges of serum 25(OH)D...

..This review summarizes the risks of vitamin D deficiency for human health and provides the current vitamin D recommendations for mothers and their newborns...

..003) and supplementation (P = 0.012). These data demonstrate that vitamin D is equally bioavailable from fortified hard cheeses and supplements, making cheese suitable for vitamin D fortification...

..Unlike some previous reports, vitamin D does not seem to be related to mammographic density in this cohort...

..001), and with study year (r(2) = 0.02; P = 0.009). Our study confirms that serum 25(OH)D concentrations undergo strong seasonal variation at high latitudes and are influenced by vitamin D intake, skin pigmentation, and sun exposure...

..We conducted a population-based case-control study to assess the evidence for a relationship between sources of vitamin D and breast cancer risk...

..The objectives of this study were to determine whether 1,25(OH)(2)D is present in human colon tissue and to characterize the relationship between human colon tissue and serum 1,25(OH)(2)D concentrations...

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..This study was conducted to determine whether daily high-dose vitamin K1 supplementation safely reduces bone loss, bone turnover, and fractures...

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..This study therefore aimed to assess the effect of this dose of vitamin D(3) in patients with bone metastases from breast cancer...

..To compare two new automated assays with the well-established reference method, DiaSorin radioimmunoassay (RIA), for quantitation of serum total 25-hydroxyvitamin D [25(OH)D]...

..Here we review the available data concerning vitamin D status and health effects of vitamin D in pregnancy through to and including adolescence...

..To compare automated platforms with the routinely used methods in our clinical laboratory for the quantitation of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)2D]...

..To examine cross-sectional associations of serum vitamin D [25-hydroxyvitamin D, 25(OH)D] concentration with insulin resistance (IR) and beta-cell dysfunction in 712 subjects at risk for type 2 diabetes...

..To determine the effect of vitamin D binding protein (DBP) genotypes on 25-hydroxyvitamin D [25(OH)D] changes with vitamin D supplements, we studied 98 adults receiving 600 or 4000 IU/d vitamin D(3) for one year...

..In this unusual case, primary hyperparathyroidism probably prevented an appropriate increase in the vitamin D-catabolizing enzyme, 25(OH)D-24-hydroxylase, thereby slowing metabolic clearance of 25(OH) vitamin D...

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..10). While the Beagley-Gibson method was associated with more variables than the skin line count method, both methods require further refinement before graded skin replicas can be recommended as a substitute for self-report measures...

..Close monitoring of biochemical responses confirmed that an increase in urinary calcium:creatinine ratio precedes hypercalcaemia as serum 25(OH)D concentrations rise...

..There were no side effects reported by any patient. Further study is needed to confirm this finding and to explore the potential therapeutic benefit of nutrient vitamin D in prostate cancer...

..These data are the first to show significant association between a common polymorphism and concentrations of a serum electrolyte. The A986S polymorphism is also a potential predisposing factor in disorders of bone and mineral metabolism...

..Recent sun exposure should correlate with circulating 25-hydroxyvitamin D [25(OH)D] due to ultraviolet B (UVB)-catalyzed cutaneous synthesis of vitamin D...

..Our aim was to assess the tolerability of high-dose oral vitamin D and its impact on biochemical, immunologic, and clinical outcomes in patients with MS prospectively...

..abstract:..

..We evaluated a 1,25(OH)(2)D enzyme immunoassay (EIA) from IDS Ltd. that uses solid-phase immunoextraction and colorimetric detection and compared results to those of the thymus radioreceptor assay (RRA) for 1,25(OH)(2)D...

..DDP level increases with AC depth and decreases with cartilage maturation. DDP is a potential indicator of cartilage metabolism during normal growth, ageing, and cartilage disease...

..This is the first demonstration of specific genetic effects on calcaneal QUS encoded by alleles of genes directly involved in mediating estrogen effects on bone...

..To determine the effect of high-protein diets, which have recently been promoted for their health benefits, on urinary calcium losses and bone turnover in older subjects...

..To examine the effect of radiotherapy for bone metastases on urinary markers of osteoclast activity...

..The CASR missense polymorphism, A986S, is common in the general population and is, therefore, a prime candidate as a genetic determinant of extracellular calcium concentration...

..Based on the available evidence, we believe that if older men and women maintain serum levels of 25(OH)D that are higher than the consensus median threshold of 75 nmol/l, they will be at lower risk of fracture...

..Vitamin D2, or ergocalciferol, should not be regarded as a nutrient suitable for supplementation or fortification...

..Recent epidemiologic, experimental, and clinical evidence support an effect for low environmental supplies of vitamin D in mediating an increased susceptibility to MS...

..Collectively, the absence of toxicity in trials conducted in healthy adults that used vitamin D dose > or = 250 microg/d (10,000 IU vitamin D3) supports the confident selection of this value as the UL...

..Hypovitaminosis D is prevalent in youth worldwide, but the safety of vitamin D at doses exceeding 200 IU/d is unknown in this age group. We assessed the safety of high doses of vitamin D(3) administered to apparently healthy schoolchildren...

..Different dosing protocols have been used for vitamin D supplementation, but there has been a lack of comparative data among them...

..Despite the high prevalence of hypovitaminosis D in children and adolescents worldwide, the impact of vitamin D deficiency on skeletal health is unclear...

..Our results are intriguing and may provide clues that further the understanding of the etiology of this highly fatal cancer...