Association of free vitamin D3 concentrations and asthma treatment failures in the VIDA Trial

Lima, John J.; Castro, Mario; King, Tonya S.; Lang, Jason E.; Ortega, Victor E.; Peters, Stephen P.; Denlinger, Loren C.; Israel, Elliot; Sorkness, Christine A.; Wechsler, Michael E.; Wenzel, Sally E.; Smith, Lewis J.

doi:10.1016/j.anai.2018.06.001

Cited by 9 publications

(13 citation statements)

References 40 publications

(70 reference statements)

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“…In addition, our findings suggest that VDBP-levels do not correlate with the levels of free 25-OHD in the circulation. This is in contrast to some previous reports also using direct methods to measure the free fraction [ 11 – 13 ]. However, taking into account that less than 5% of the binding sites on VDBP are occupied by 25-OHD [ 3 ], it is reasonable to suggest that VDBP levels only have a minor impact on the levels of free 25-OHD.…”

Section: Main Textcontrasting

confidence: 76%

Vitamin D binding protein is not affected by high-dose vitamin D supplementation: a post hoc analysis of a randomised, placebo-controlled study

et al. 2018

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ObjectivesVitamin D binding protein (VDBP) is the main transporter of 25-hydroxyvitamin D3 (25-OHD) in the circulation. The aim of this study was to investigate if VDBP is affected by high dose vitamin D supplementation and if VDBP-levels correlate with free 25-OHD. Correlation between free 25-OHD measured with ELISA and total 25-OHD in the circulation was also analysed. Plasma samples from a randomized, controlled trial in which persistent MRSA-carriers were randomized to treatment with vitamin D, 4000 IE/day, (n = 27) or placebo (n = 32) for 12 months were used. Plasma from baseline and after 6 months of treatment were analysed for VDBP, 25-OHD and free 25-OHD.ResultsVDBP levels were not affected by vitamin D treatment, although the 25-OHD levels increased significantly in the vitamin D treated subjects. There was a strong correlation between 25-OHD and free 25-OHD (r2 = 0.68, p < 0.0001), while there was no correlation between VDBP and free 25-OHD. Thus, our data shows that VDBP are not affected by vitamin D supplementation and the levels of VDBP are not associated with the free fraction of 25-OHD. Since there was a strong correlation between free 25-OHD and total 25-OHD it appears to be sufficient to measure only total 25-OHD.Trial registration http://www.clinicaltrials.gov; NCT02178488. Date of registration: June 30, 2014; Date of enrolment of the first participant: Dec 1, 2014

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Section: Main Textcontrasting

confidence: 76%

Vitamin D binding protein is not affected by high-dose vitamin D supplementation: a post hoc analysis of a randomised, placebo-controlled study

et al. 2018

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“…Some study limitations occurred. Like many other observational studies, [52][53][54] this was an ancillary analysis of data from a randomized clinical trial designed to investigate a different research question, which may limit generalizability of our results. FFQ analysis of nutrient intake is subject to presumably non-differential measurement bias.…”

Section: Discussionmentioning

confidence: 99%

“…Male 391 (53) 129 62261 (49) 133 5451 6182 (51) 421 (52) 136 62261 (49) Female 347 (47) 78 (38) 269 (51) 112 4633 (39) 79 (49) 385 (48) 82 (38) 269 (51) Race/ethnicity, number (%)…”

Section: Correlations Between Dietary and Plasma Polyunsaturated Fattmentioning

confidence: 99%

Dietary and Plasma Polyunsaturated Fatty Acids Are Inversely Associated with Asthma and Atopy in Early Childhood

Lee-Sarwar

Kelly

Lasky‐Su

et al. 2019

The Journal of Allergy and Clinical Immunology: In Practice

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“…In some studies free serum 25(OH)D levels were inversely associated with coronary artery disease (125), pediatric inflammatory bowel disease (126) and ulcerative colitis (127), insulin sensitivity (128), reduction in lipid markers in statin patients (129), and acromegaly (130). However, in some other studies free 25(OH)D was inferior in asthma (131) and no better than total 25(OH)D for colorectal cancer in African-Americans (132).…”

Section: Human Studies Of Free 25(oh)dmentioning

confidence: 90%

Vitamin D Binding Protein and the Biological Activity of Vitamin D

et al. 2019

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Vitamin D has a long-established role in bone health. In the last two decades, there has been a dramatic resurgence in research interest in vitamin D due to studies that have shown its possible benefits for non-skeletal health. Underpinning the renewed interest in vitamin D was the identification of the vital role of intracrine or localized, tissue-specific, conversion of inactive pro-hormone 25-hydroxyvitamin D [25(OH)D] to active 1,25-dihydroxyvitamin D [1,25(OH)2D]. This intracrine mechanism is the likely driving force behind vitamin D action resulting in positive effects on human health. To fully capture the effect of this localized, tissue-specific conversion to 1,25(OH)2D, adequate 25(OH)D would be required. As such, low serum concentrations of 25(OH)D would compromise intracrine generation of 1,25(OH)2D within target tissues. Consistent with this is the observation that all adverse human health consequences of vitamin D deficiency are associated with a low serum 25(OH)D level and not with low 1,25(OH)2D concentrations. Thus, clinical investigators have sought to define what concentration of serum 25(OH)D constitutes adequate vitamin D status. However, since 25(OH)D is transported in serum bound primarily to vitamin D binding protein (DBP) and secondarily to albumin, is the total 25(OH)D (bound plus free) or the unbound free 25(OH)D the crucial determinant of the non-classical actions of vitamin D? While DBP-bound-25(OH)D is important for renal handling of 25(OH)D and endocrine synthesis of 1,25(OH)2D, how does DBP impact extra-renal synthesis of 1,25(OH)2D and subsequent 1,25(OH)2D actions? Are their pathophysiological contexts where total 25(OH)D and free 25(OH)D would diverge in value as a marker of vitamin D status? This review aims to introduce and discuss the concept of free 25(OH)D, the molecular biology and biochemistry of vitamin D and DBP that provides the context for free 25(OH)D, and surveys in vitro, animal, and human studies taking free 25(OH)D into consideration.

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Association of free vitamin D3 concentrations and asthma treatment failures in the VIDA Trial

Cited by 9 publications

References 40 publications

Vitamin D binding protein is not affected by high-dose vitamin D supplementation: a post hoc analysis of a randomised, placebo-controlled study

Vitamin D binding protein is not affected by high-dose vitamin D supplementation: a post hoc analysis of a randomised, placebo-controlled study

Dietary and Plasma Polyunsaturated Fatty Acids Are Inversely Associated with Asthma and Atopy in Early Childhood

Vitamin D Binding Protein and the Biological Activity of Vitamin D

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