Trial reportThe Journal of clinical endocrinology and metabolism2021
Total, Bioavailable, and Free 25(OH)D Relationship with Indices of Bone Health in Elderly: A Randomized Controlled Trial.
Trial report in The Journal of clinical endocrinology and metabolism, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
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
16 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Clinical Practice Guidelines of the Latin American Federation of Endocrinology for the use of vitamin D in the maintenance of bone health: recommendations for the Latin American context.Archives of osteoporosis · 2024Guideline
- Variation of bone-related and inflammatory biomarkers after a half-marathon running in trained subjects.European journal of applied physiology · 2025Article
- Reference Intervals for 24-Hour Urinary Calcium Excretion and Its Association With Bone Metabolism: A Multicenter Study.The Journal of clinical endocrinology and metabolism · 2025Article
- Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows.Endocrine reviews · 2024Article
- Circulating total 25(OH)D and calculated free 25(OH)D in professional academy footballers at a northerly latitude in the UK.Biology of sport · 2024Article
- Total and free 25-hydroxyvitamin D concentrations and risk of urinary incontinence in women participating in Nurses Health Studies I & II.The American journal of the medical sciences · 2023Article
- Vitamin D and Calcium in Osteoporosis, and the Role of Bone Turnover Markers: A Narrative Review of Recent Data from RCTs.Diseases (Basel, Switzerland) · 2023Article
- Free and bioavailable 25-hydroxyvitamin D thresholds for bone metabolism and their associations with metabolic syndrome in Chinese women of childbearing age.Frontiers in nutrition · 2023Article
- Rapidly Increasing Serum 25(OH)D Boosts the Immune System, against Infections-Sepsis and COVID-19.Nutrients · 2022Article
- Absence of causal association between Vitamin D and bone mineral density across the lifespan: a Mendelian randomization study.Scientific reports · 2022Article
- Free and Bioavailable Vitamin D Levels of Patients with Type 1 Diabetes Mellitus and Association with Bone Metabolism.Journal of diabetes and metabolic disorders · 2022Article
- Targeting Sirt1, AMPK, Nrf2, CK2, and Soluble Guanylate Cyclase with Nutraceuticals: A Practical Strategy for Preserving Bone Mass.International journal of molecular sciences · 2022Review
- Directly measured free and total 25-hydroxyvitamin D levels in relation to metabolic health in multi-ethnic postmenopausal females in Saudi Arabia.Endocrine connections · 2021Article
- Article
- Total, Bioavailable, and Free 25-Hydroxyvitamin D Equally Associate with Adiposity Markers and Metabolic Traits in Mexican Adults.Nutrients · 2021Article
- Effect of Summer Sunshine Exposure on Vitamin D Status in Young and Middle Age Poles: Is 30 ng/mL Vitamin D Cut-Off Really Suitable for the Polish Population?International journal of environmental research and public health · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors.
Funding
Abstract
contextQuestions regarding the superiority of free and bioavailable 25-hydroxyvitamin D [25(OH)D] in predicting health outcomes remain unresolved.
objectiveThis study investigates the impact of vitamin D variables-total, bioavailable, or free 25(OH)D-on indices of bone and mineral metabolism, at baseline and in response to 2 vitamin D doses.
designOur objectives are implemented as exploratory analyses on data collected in a 1-year, double-blind, randomized controlled trial completed in July 2014.
settingParticipants were recruited from 3 major hospitals in an ambulatory setting.
participantsParticipants were >65 years of age, overweight, and had a baseline serum 25(OH)D between 10 and 30 ng/mL. A total of 221 participants completed the study.
interventionSubjects were randomized to receive calcium and oral vitamin D3 (600 IU/day or 3750 IU/day) supplementation.
resultsParticipants who received the higher vitamin D dose had levels that were 1.3- to 1.4-fold higher than those taking the lower dose, for all variables (P value < 0.001). Serum values of bioavailable and free 25(OH)D were associated with total 25(OH)D, with r values of 0.942 and 0.943, respectively (P value < 0.001). Parathyroid hormone (PTH) was negatively associated with all vitamin D variables, with correlation coefficients ranging from -0.22 to -0.25, while calcium and bone turnover markers (carboxy-terminal collagen crosslinks and osteocalcin) did not. Only total 25(OH)D had a positive relationship with % change bone mineral density (BMD) at the femoral neck at 12 months, while only free and bioavailable 25(OH) had a positive relationship with % change total body BMD at 12 months.
conclusionCalculated free and bioavailable 25(OH)D do not appear to be superior to total 25(OH)D in predicting indices of bone health in an elderly population.
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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.