scholarly journals Significance of Serum 24,25-Dihydroxyvitamin D in the Assessment of Vitamin D Status: A Double-edged Sword?

2015 ◽  
Vol 61 (4) ◽  
pp. 636-645 ◽  
Author(s):  
Kevin D Cashman ◽  
Aoife Hayes ◽  
Karen Galvin ◽  
Joyce Merkel ◽  
Glenville Jones ◽  
...  
Keyword(s):  
Vitamin D ◽  
Representative Sample ◽  
Controlled Trial ◽  
Cross Reactivity ◽  
Vitamin D Supplementation ◽  
Positive Bias ◽  
Dihydroxyvitamin D ◽  
Spiking Experiment ◽  
Nationally Representative ◽  
The Impact

Abstract BACKGROUND 24,25-Dihydroxyvitamin D [24,25(OH)2D] in serum may be both a nuisance and nutritionally valuable. METHODS We investigated the impact of 24,25(OH)2D3 on the performance of commercially available immunoassays for serum total 25-hydroxyvitamin D [25(OH)D] using (a) serum from a nationally representative sample of adults, (b) serum from a spiking experiment, and (c) data from the UK Vitamin D External Quality Assurance Scheme (DEQAS). We also investigated the utility of the serum ratio of 24,25(OH)2D3 to 25(OH)D as an index of inactivation and of response to vitamin D supplementation using randomized controlled trial (RCT) data. Measurement of 24,25(OH)2D in sera by a LC-MS/MS method allowed for an investigation of its impact on immunoassay-derived serum 25(OH)D values as well as its clinical utility. We report data from a nationally representative sample of adults, a recent vitamin D RCT in older adults, and DEQAS. RESULTS 24,25(OH)2D3 contributed to the positive bias observed in some immunoassays relative to LC-MS/MS-derived estimates for total 25(OH)D. A spiking experiment showed that the degree of cross-reactivity with 24,25(OH)2D was high and may underpin this positive bias. Adjustment for 24,25(OH)2D3 concentration brought estimates closer to true values. Data from the vitamin D RCT showed that the ratio of 24,25(OH)2D3 to 25(OH)D was associated with serum 25(OH)D3 and with response of serum 25(OH)D to vitamin D supplementation. CONCLUSIONS Our findings highlight that the effect of 24,25(OH)2D3 in serum is a double-edged sword—an interferent for some immunoassays, yet potentially informative of nutritional status.

scholarly journals Effect of Prenatal Vitamin D Supplementation on Placental Angiogenic Factors in Bangladesh (FS08-07-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Anita Subramanian ◽  
Casey Carr ◽  
Eszter Papp ◽  
Kellie Murphy ◽  
Abdullah Al Mahmud ◽  
...  
Keyword(s):  
Vitamin D ◽  
Growth Factor ◽  
Controlled Trial ◽  
Secondary Analysis ◽  
Vitamin D Supplementation ◽  
Angiogenic Factors ◽  
Fetal Sex ◽  
Maternal Vitamin ◽  
The Mean ◽  
The Impact

Abstract Objectives To determine the effect of prenatal vitamin D supplementation on expression of angiogenic factors in the placenta. Methods This is a secondary analysis of the Maternal Vitamin D for Infant Growth trial, a randomized controlled trial of maternal vitamin D supplementation in Dhaka, Bangladesh. We examined the expression of angiogenic factors in placental tissues. Women (n = 1300) were enrolled at 17–24 weeks gestation and randomized to receive: placebo, 4200 IU/week, 16,800 IU/week or 28,000 IU/week until delivery. We examined a subset of randomly selected placentas (n = 80) collected at birth, which included 20 tissues (10 male & 10 female offspring) from each treatment group in maternal/fetal pairs. A full thickness placental core was collected; fixed in formalin and embedded in paraffin. Tissue sections were stained for vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) using immunofluorescence. ImageJ was used to quantify intensity and % area of expression. T-tests were used to estimate the effects of each vitamin D dose on expression of angiogenic factors, compared to placebo. Interactions by fetal sex were also examined. Results The mean (SD) for % area of expression was 17.0 (4.0) for VEGF and 14.8 (1.9) for PlGF. The mean (SD) for intensity was 6520 (1549) for VEGF and 5716 (734) for PlGF. There were no significant differences in VEGF and PlGF between any vitamin D treatment groups versus placebo for % area or intensity of expression (Table 1). The effect of vitamin D treatment was not modified by fetal sex. Conclusions Vitamin D supplementation starting from mid-pregnancy until delivery did not effect expression of two key angiogenic factors in the placenta at term. The impact of periconception vitamin D supplementation on expression of angiogenic factors in the placenta remains unknown. Funding Sources Bill and Melinda Gates Foundation. Supporting Tables, Images and/or Graphs

scholarly journals The impact of vitamin D supplementation on VDR gene expression and body composition in monozygotic twins: randomized controlled trial

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jeane Franco Pires Medeiros ◽  
Michelle Vasconcelos de Oliveira Borges ◽  
Aline Alves Soares ◽  
Jessica Cavalcante dos Santos ◽  
Ana Beatriz Bezerra de Oliveira ◽  
...  
Keyword(s):  
Gene Expression ◽  
Vitamin D ◽  
Randomized Controlled Trial ◽  
Body Composition ◽  
Controlled Trial ◽  
Monozygotic Twins ◽  
Vitamin D Supplementation ◽  
Vdr Gene ◽  
Randomized Controlled ◽  
The Impact
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