ArticleThe Journal of clinical endocrinology and metabolism2015
Free 25(OH)D and the Vitamin D Paradox in African Americans.
Article in The Journal of clinical endocrinology and metabolism, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 72 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
72 citing papers in PubMed, 1 synthesis or guideline pooled it, 116 citations in OpenAlex.
- The role of vitamin D in the age of COVID-19: A systematic review and meta-analysis.International journal of clinical practice · 2021Pooled it
- Association of free vitamin DAnnals of allergy, asthma & immunology : official publication of the American College of Allergy, Asthma, & Immunology · 2018Trial
- Associations Between Change in Total and Free 25-Hydroxyvitamin D With 24,25-Dihydroxyvitamin D and Parathyroid Hormone.The Journal of clinical endocrinology and metabolism · 2018Trial
- The relationship of Physical performance and Osteoporosis prevention with vitamin D in older African Americans (PODA).Contemporary clinical trials · 2018Trial
- Effects of Cholecalciferol vs Calcifediol on Total and Free 25-Hydroxyvitamin D and Parathyroid Hormone.The Journal of clinical endocrinology and metabolism · 2017Trial
- Effects of High-Dose Vitamin D2 Versus D3 on Total and Free 25-Hydroxyvitamin D and Markers of Calcium Balance.The Journal of clinical endocrinology and metabolism · 2016Trial
- Vitamin D status of black and white Americans and changes in vitamin D metabolites after varied doses of vitamin D supplementation.The American journal of clinical nutrition · 2016Trial
- Effects of vitamin D binding protein phenotypes and vitamin D supplementation on serum total 25(OH)D and directly measured free 25(OH)D.European journal of endocrinology · 2016Trial
- Treatment of Vitamin D Deficiency in Predominantly Hispanic and Black Adolescents: A Randomized Clinical Trial.The Journal of pediatrics · 2016Trial
- Free 25-Hydroxyvitamin D Concentrations in Cystic Fibrosis.The American journal of the medical sciences · 2015Trial
- Vitamin D as a cellular endocrine system: Tissue-specific microcircuits, immune reprogramming, and metabolic resistance.iScience · 2026Review
- Interlaboratory comparison with a reference measurement procedure (RMP) for determining 24,25-dihydroxyvitamin DAnalytical and bioanalytical chemistry · 2026Article
- Vitamin D and the metabolic-associated steatotic liver disease-type 2 diabetes axis: a scoping-narrative review of global evidence and emerging perspectives for Sub-Saharan Africa.Frontiers in epidemiology · 2026Review
- Investigation of the Relationship between Vitamin D Deficiency and Vitamin D-Binding Protein Polymorphisms in Severe COVID-19 Patients.Diagnostics (Basel, Switzerland) · 2024Article
- Vitamin D/Bone Mineral Density and Triglyceride Paradoxes Seen in African Americans: A Cross-Sectional Study and Review of the Literature.International journal of molecular sciences · 2024Review
- Seasonal variation of total and bioavailable 25-hydroxyvitamin D [25(OH)D] in the healthy adult Slovenian population.Acta biochimica Polonica · 2024Article
- Multimarker Approach as More Reliable Method Than Single Vitamin D in Relationship with Type 2 Diabetes Mellitus in Montenegrin Postmenopausal Women.Biomedicines · 2023Article
- Determination of 24,25-dihydroxyvitamin DThe Journal of steroid biochemistry and molecular biology · 2023Article
- Effect of vitamin D metabolites on bone histomorphometry in healthy black and white women: An attempt to unravel the so-called vitamin D paradox in blacks.Bone reports · 2023Article
- Association of circulating serum free bioavailable and total vitamin D with cathelicidin levels among active TB patients and household contacts.Scientific reports · 2023Article
12 more citing papers are in PubMed but not listed here.
Corrections and comments
- Erratum issuedCORRIGENDUM.2016
Authors and funding
8 authors at 1 institution in 1 country.
Funding
Abstract
contextAfrican Americans have a lower total serum 25-hydroxyvitamin D [25(OH)D] but superior bone health. This has been referred to as a paradox. A recent publication found that free serum 25(OH)D is the same in black and white individuals. However, the study was criticized because an indirect method was used to measure free 25(OH)D. A direct method has recently been developed.
objectiveWe hypothesized that although total serum 25(OH)D is lower in African Americans, free serum 25(OH)D measured directly would not differ between races.
designWhite and black healthy postmenopausal women were matched for age and body mass index. Serum total 25(OH)D, PTH, 1,25-dihydroxyvitamin D, vitamin D binding protein (VDBP), and bone density were measured. Measurement of free 25(OH)D was carried out using an ELISA.
settingThe study was conducted at an ambulatory research unit in a teaching hospital. OUTCOME: A cross-racial comparison of serum free 25(OH)D was performed.
resultsA propensity match resulted in the selection of a total of 164 women. Total 25(OH)D was lower in black women (19.5 ± 4.7 vs 26.9 ± 6.4 ng/mL), but a direct measurement of free 25(OH)D revealed almost identical values (5.25 ± 1.2 vs 5.25 ± 1.3 ng/mL) between races. VDBP was significantly lower in blacks when using a monoclonal-based ELISA but higher with a polyclonal-based ELISA. Serum PTH, 1,25-dihydroxyvitamin D, and bone density were higher in African Americans.
conclusionsFree serum 25(OH)D is the same across races despite the lower total serum 25(OH)D in black women. Results comparing VDBP between races using a monoclonal vs a polyclonal assay were discordant.
Indexed as
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.