Distribution and determinants of vitamin D-binding protein, total, “non-bioavailable”, bioavailable, and free 25-hydroxyvitamin D concentrations among older adults

• Verfasst von: Zhu, Anna [VerfasserIn]
• Verfasst von: Kuznia, Sabine [VerfasserIn]
• Verfasst von: Niedermaier, Tobias [VerfasserIn]
• Verfasst von: Holleczek, Bernd [VerfasserIn]
• Verfasst von: Schöttker, Ben [VerfasserIn]
• Verfasst von: Brenner, Hermann [VerfasserIn]
• Titel: Distribution and determinants of vitamin D-binding protein, total, “non-bioavailable”, bioavailable, and free 25-hydroxyvitamin D concentrations among older adults
• Verf.angabe: Anna Zhu, Sabine Kuznia, Tobias Niedermaier, Bernd Holleczek, Ben Schöttker, and Hermann Brenner
• E-Jahr: 2021
• Jahr: 9 November 2021
• Umfang: 14 S.
• Fussnoten: Gesehen am 13.01.2022 ; This article belongs to the special issue "Vitamins and human health: systematic reviews"
• Titel Quelle: Enthalten in: Nutrients
• Ort Quelle: Basel : MDPI, 2009
• Jahr Quelle: 2021
• Band/Heft Quelle: 13(2021), 11, special issue, Artikel-ID 3982, Seite 1-14
• ISSN Quelle: 2072-6643
• DOI: doi:10.3390/nu13113982
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: bioavailable 25(OH)D
• Sach-SW: determinants
• Sach-SW: free 25(OH)D
• Sach-SW: vitamin D-binding protein
• K10plus-PPN: 178594990X

Abstract

Background: serum 25-hydroxyvitamin D (25(OH)D) (“total 25 OH(D)”) is the most commonly used indicator of vitamin D status. However, 25(OH)D is mostly bound to the vitamin D binding protein (VDBP) or albumin in blood, and it has been suggested that the remaining bioavailable or free 25(OH)D may be more relevant for vitamin D associated health outcomes. We aimed to explore distributions and determinants of VDBP, total, bioavailable, complementary “non-bioavailable”, and free 25(OH)D in a large cohort of older adults in Germany. Methods: total 25(OH)D, VDBP, and albumin concentrations were measured in blood samples of 5899 men and women aged 50-75 years and used to calculate bioavailable (and complementary “non-bioavailable”) and free 25(OH)D concentrations. Linear regression models were used to evaluate associations of potential determinants of the various vitamin D biomarkers. Results: mean concentrations of VDBP, total, non-bioavailable, bioavailable, and free 25(OH)D were 323.6 µg/mL, 49.8 nmol/L, 43.4 nmol/L, 2.5 ng/mL, and 5.7 pg/mL, respectively. Seasonal variations were observed for all markers, with peak values in spring for VDBP and in summer for total, non-bioavailable, bioavailable, and free 25(OH)D. Consistent inverse associations were seen with age and body mass index for all markers, but divergent associations were seen with C-reactive protein. Strong variations by VDBP genotypes were seen for bioavailable and free 25(OH)D, and, in opposite direction for non-bioavailable 25(OH)D. Conclusion: commonalities and differences in determinants of various markers of vitamin D status were observed, which may help to enable a better understanding of their potential role for various vitamin D related health outcomes.