Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults

Vitamin D-Do Diet Recommendations for Health Remain Strong?

How will the scientific community and authoritative bodies define future nutritional requirements for vitamin D? At the International Symposium on Nutritional Aspects of Musculoskeletal Health, the authors debated the strength of current evidence for setting vitamin D intake recommendations from diet: the positive side of the strength of the evidence (PRO) suggests there is a physiological requirement for vitamin D and the opposing view (CON) that in light of negative results from large, recent trials, particularly those with fractures and bone health outcomes, we are left rudderless. Should we provide recommendations based on empiric treatment of vitamin D for most groups and conditions? It is becoming increasingly evident that vitamin D plays a role in many physiological functions and processes associated with long-term human health; however, to what extent are these benefits apparent beyond what is needed for adequate nutritional status, measured as serum 25-hydroxyvitamin D levels, for active calcium absorption? The meeting attendees voted for the PRO vs. CON position at the end of the session.

Trabecular bone score norms in Asian-Indians and associations with serum 25(OH)D and parathyroid hormone

OBJECTIVE

There is limited information on population-specific norms of trabecular-bone-score (TBS) and its associated factors. Here, we provide norms of TBS in Asian-Indians and its relationship with serum 25-hydroxyvitamin D [25(OH)D] and intact-parathyroid hormone (iPTH).

PARTICIPANTS AND MEASUREMENTS

TBS, bone-mineral-density (BMD), and vertebral-fractures (VFs) were assessed using dual-energy X-ray absorptiometry in 923 healthy Asian-Indians (aged 20-60 years). Serum 25(OH)D, iPTH, T4/TSH,, glycosylated-haemoglobin (HbA1c) were measured and associations with TBS assessed using multivariable linear regression. Subjects with BMD Z-score ≤ -2.0 or ≥2.0 at any sites, VFs, TSH > 10.0 or <0.05 µIU/ml, blood-glucose >11.1 mmol/L or HbA1c > 8.0% were excluded for generating Asian-Indian norms.

RESULTS

TBS norms were generated in 744 healthy Asian-Indians (M:F,389:385). The cut-offs generated for 'normal', 'partially-degraded', and 'degraded' TBS were >1.305, 1.204-1.305 and <1.204, respectively. Mean TBS was lower in females than males (p < .001). There was 75% congruency in TBS categories between Asian-Indian and existing norms. Specificity (97.8 vs. 77.9%, p < .001) and diagnostic-accuracy (97.8% vs. 78.4%, p < .001) of TBS to detect osteoporosis were higher with Asian-Indian norms. The sensitivity of 'partially-degraded' TBS to diagnose osteopenia was also higher with Asian-Indian norms. In multivariable regression, gender, body-mass-index (BMI), BMD-L1-L4, serum PTH, daily dietary-calorie intake and calcium intake were associated with TBS. Though 25(OH)D inversely correlated with PTH, 25(OH)D was not associated with TBS.

CONCLUSION

This study provides norms for TBS in Asian-Indians with gender-specific differences. Increasing age and higher BMI were associated with lower TBS. Associations of TBS with circulating PTH and/or 25(OH)D need confirmation in further studies.

Vitamin D Supplementation and the Incidence of Fractures in the Elderly Healthy Population: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Although a well-established component of bone metabolism, the efficacy and safety of vitamin D supplementation for the prevention of fractures in elderly healthy individuals is still unclear.

PURPOSE

To perform a meta-analysis comparing vitamin D supplementation with placebo and its contributions on fracture incidence.

METHODS

This meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), under protocol CRD42023484979. We systematically searched PubMed, Embase, and Cochrane Central databases from inception to November 2023 for randomized controlled trials (RCTs) comparing vitamin D supplementation versus placebo in individuals with 60 years of age or more and without bone related medical conditions such as cancer and osteoporosis.

RESULTS

Seven RCTs with 71,899 patients were included, of whom 36,822 (51.2%) were women. There was no significant difference in total fracture incidence (RR 1.03; 95% CI 0.93-1.14; p = 0.56; I2 = 58%) between groups or subgroups. However, women had an increased risk for hip fractures (164 vs. 121 events; RR 1.34; 95% CI 1.06-1.70; p = 0.01; I2 = 0%). There was no significant difference in non-vertebral fractures, osteoporotic fractures development, or falls (RR 1.02; 95% CI 0.94-1.12; p = 0.6; I2 = 47%; RR 0.97; 95% CI 0.87-1.08; p = 0.63; I2 = 0%; RR 1.01; 95% CI 0.97-1.04; p = 0.66; I2 = 55%, respectively).

CONCLUSION

Vitamin D supplementation does not reduce the total fracture development rate in the elderly healthy population, and it may increase the incidence of hip fractures among elderly healthy women. This finding suggests refraining from prescribing high intermittent doses of vitamin D, without calcium, to individuals aged 60 or older with unknown vitamin D serum concentration or osteoporosis status and inadequate calcium intake.

Prevalence of low vitamin D levels among older US Asian and Pacific Islander adults

While US Asian and Pacific Islander adults have lower 25-hydroxyvitamin D (25(OH)D) levels than White adults, ethnic subgroup data remain limited. In a large California population, the adjusted prevalence of 25(OH)D < 20 ng/mL (50 nmol/L) was 1.5- to 2.7-fold higher for Asian/Pacific Islander compared to White adults, with substantial variation by ethnicity.

PURPOSE

US Asian and Pacific Islander (PI) adults generally have lower 25-hydroxyvitamin D [25(OH)D] levels than non-Hispanic White (NHW) adults, but subgroup data remain limited. We compared sex- and ethnicity-specific prevalence of low 25(OH)D among older Asian/PI and NHW adults.

METHODS

Data from 102,556 Asian/PI and 381,724 NHW adults aged 50-89 years with measured 25(OH)D in 2012-2019 and body mass index (BMI, within ± 1 year) were examined in a California healthcare system. Low 25(OH)D < 20 ng/mL (50 nmol/L) was examined by race and ethnicity. Covariates included age, smoking, BMI, and season of measurement. Modified Poisson regression was used to estimate prevalence ratios (aPR), adjusting for covariates.

RESULTS

Among 31,287 Asian/PI men and 71,269 Asian/PI women, the prevalence of low 25(OH)D was 22.6% and 14.7%, respectively, significantly higher than observed for 122,162 NHW men (12.3%) and 259,562 NHW women (9.9%). Within Asian/PI subgroups, low 25(OH)D prevalence ranged from 17 to 18% (Korean, Japanese, Filipino), 22 to 24% (Chinese, Vietnamese), 28% (South Asian), and 35% (Native Hawaiian/PI) among men and 11 to 14% (Japanese, Filipina, Chinese, Korean), 17 to 18% (South Asian, Vietnamese), and 26% (Native Hawaiian/PI) among women. The corresponding aPRs (NHW reference) for men and women were as follows: Native Hawaiian/PI, 2.70 and 2.34; South Asian, 2.56 and 2.07; Vietnamese, 2.17 and 2.31; Chinese, 2.04 and 1.89; Korean, 1.60 and 1.85; Filipino, 1.58 and 1.52; and Japanese, 1.58 and 1.49 (p < 0.001).

CONCLUSION

In a large US healthcare population of older Asian/PI adults, low 25(OH)D prevalence was 1.5- to 2.7-fold higher for Asian/PI compared to NHW adults, with substantial variation by sex and ethnicity.

Revisiting Vitamin D Guidelines: A Critical Appraisal of The Literature

The goal of this Review is to compare the 2024 and 2011 Endocrine Society's Clinical Guidelines on Vitamin D. The 2024 Guideline made recommendations for the general healthy population for skeletal and extra skeletal health benefits of vitamin D. This contrasts with the 2011 Guidelines which provided clinicians with guidance for how to evaluate and treat patients with vitamin D deficiency and prevent recurrence. The 2024 Guideline focused on randomized controlled trials and ignored association studies and other studies that have supported the skeletal and extraskeletal health the benefits of vitamin D. The 2024 Guideline recommended empiric vitamin D in children and adolescents aged 1 to 18 years to reduce risk of upper respiratory tract infections, pregnant women to improve pregnancy related outcomes, prediabetic patients to reduce risk of diabetes and to improve mortality in those over 75 years. These guidelines do not apply to individuals with abnormalities in calcium, phosphate, vitamin D and bone metabolism which were provided in the 2011 Guidelines. For nonpregnant adults up to the age of 75 they recommend the Dietary Reference Intakes of 600 IUs, and 800 IUs as recommended by The Institute of Medicine. Association studies have suggested that to obtain maximum extraskeletal benefits from vitamin D including reducing risk of upper respiratory tract infection for children and adults, autoimmune disorders, preeclampsia, low birth weight, neonatal dental caries and deadly cancers that circulating concentrations of 25-hydroxyvitamin D should be at least 30 ng/mL with a preferred range of 40-60 ng/mL as recommended by the 2011 Guidelines.

Prevalence of medication overload among older people with HIV: a MedSafer study

BACKGROUND

Older people with HIV (PWH) are at risk of polypharmacy (taking multiple medications). Most medications may be necessary and indicated to manage HIV (e.g., antiretroviral therapy [ART]) and HIV-associated comorbidities. However, some are potentially inappropriate medications (PIMs), defined as causing greater harm than benefit, which leads to medication overload. The objective of this study was to characterize polypharmacy (taking multiple medications) and medication overload (prescription of ≥ 1 PIMs) among older PWH.

METHODS

This retrospective study included older PWH (aged ≥ 50 years old) attending the tertiary care HIV clinic at the McGill University Health Centre (Montreal, Canada), from June 2022-June 2023. Patient characteristics, medications, and select laboratory values (e.g., CD4 count, hemoglobin A1C) were entered into the MedSafer software identifying PIMs and classifying them according to risk of adverse drug event. We measured the prevalence of polypharmacy (≥ 5 medications prescribed, both including and excluding ART) and medication overload (≥ 1 PIMs). Multivariable logistic regression identified factors associated with medication overload.

RESULTS

The study included 100 patients, with a median age of 59 years (IQR = 54-63; range 50-82); 42% female. Polypharmacy affected 89% of patients when including antiretroviral therapy (ART) and 60% when excluding ART. Medication overload was present in 58% of patients, and 37.4% of identified PIMs were classified as high-risk. Polypharmacy was the sole predictor of medication overload.

CONCLUSION

Older PWH are at significant risk of medication overload and receiving higher risk PIMs. Deprescribing PIMs in this population could improve medication appropriateness while reducing the risk of ADEs.

The essential role of combined calcium and vitamin D supplementation in the osteoporosis scenario in italy: Expert opinion paper

An Italian multidisciplinary working group discussed the current Italian scenario of osteoporosis management during a meeting and highlighted the essential role of calcium and vitamin D supplementation in the prevention of fragility fractures.

PURPOSE

This paper aims to review and discuss data on calcium and vitamin D requirements and the role of combined calcium and vitamin D supplementation in the treatment of patients with osteoporosis.

METHODS

The discussion of the experts covered literature data on calcium and vitamin D supplementation, gaps in the diagnosis and treatment of osteoporosis, and the role of the primary care physician in identifying and treating patients with osteoporosis. Articles for consideration were identified through PubMed searches using different combinations of pertinent keywords.

RESULTS

The discussion highlighted that insufficient calcium or vitamin D intake increases the risk of fragility fractures. The experts also drew attention to the essential role of calcium and vitamin D supplementation in achieving an anti-fracture effect and supporting the efficacy of anti-osteoporotic agents without increasing nephrolithiasis and cardiovascular risks. In addition, the discussion underlined the role of the primary care physician in the initial clinical approach to patients with osteoporosis.

CONCLUSIONS

The experts believe that efficient treatment for patients with osteoporosis should include calcium and vitamin D supplementation to achieve adequate levels that are able to inhibit the parathyroid hormone and bone resorption.

Equivalence in osteoporosis workup and management after femoral neck fracture fixation and vertebral compression fracture cement augmentation: A single-center retrospective study highlighting persistent Underdiagnosis and Undertreatment

Background

The purpose of this study was to evaluate pre- and post-fracture medical management of osteoporosis among patients who underwent surgical fixation of femoral neck fractures (FNF) and vertebral compression fractures (VCF), and to investigate if there is a difference in treatment, management, and subsequent fractures between FNF and VCF patients.

Methods

Patients who underwent surgical fixation of FNF or VCF were retrospectively reviewed at a minimum 1 year follow up. Patients were excluded if their fracture was caused by high energy trauma or malignancy, <50 years-old, deceased, or lost to follow up. Patient demographics such as age, sex, BMI, American Society of Anesthesiology Physical Status Classification System and Charleston Comorbidity index were recorded. Management of osteoporosis, including medication regimen and dual-energy X-ray absorptiometry (DEXA) scans were assessed preoperatively and at minimum one year follow up. Subsequent fractures were also recorded.

Results

In the analysis of 370 patients (74.7% FNF, 25.2% VCF), demographics showed a predominantly female population (mean age 78.1). Preoperatively, 21.6% were diagnosed with osteoporosis, consistent between FNF and VCF. Postoperatively, there were no significant differences in new osteoporosis diagnoses, bisphosphonate use, or subsequent fractures. VCF patients, however, were more likely to receive denosumab and post-operative DEXA scans (p < 0.05). Within a year, 6.2% experienced subsequent fractures, with no significant FNF-VCF difference. Only 12.7% received appropriate post-operative osteoporosis treatment, 27.1% had DEXA scans, and 25% had a recorded osteoporosis diagnosis. Multivariable analysis highlighted pre-fracture osteoporosis diagnosis as the sole predictor for post-operative DEXA scans and anti-osteoporotic medication (p < 0.001).

Conclusions

This study suggests that factors beyond the type of fragility fracture may influence subsequent fracture risk and anti-osteoporotic medication administration in elderly patients. These findings underscore the importance of a comprehensive approach to fracture risk assessment and treatment decisions in this population.

Level of evidence

III.

Vitamin D assay and supplementation: still debatable issues

Over the last decades, in addition to the improvement of pathophysiological knowledge regarding the role and mechanisms of action of vitamin D, there has been a progressive advancement in analytical technologies for its measurement, as well as in methodological standardization. A significant number of scientific works, meta-analyses, and guidelines have been published on the importance of vitamin D and the need for supplementation in deficient individuals. However, it appears necessary to clarify the fundamental elements related to the measurement of vitamin D (both at the strictly analytical and post-analytical levels) and the scientific evidence related to the efficacy/safety of supplementation. In particular, there is a need to discuss current recommended levels for deficiency, insufficiency and possible toxicity in the light of evidence from standardization projects. Additionally, given the important interrelations between vitamin D, parathyroid hormone (PTH), and fibroblast growth factor-23 (FGF23), the analytical issues and clinical utility of these biomarkers will be discussed.

Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows

The 6th International Conference, "Controversies in Vitamin D," was convened to discuss controversial topics, such as vitamin D metabolism, assessment, actions, and supplementation. Novel insights into vitamin D mechanisms of action suggest links with conditions that do not depend only on reduced solar exposure or diet intake and that can be detected with distinctive noncanonical vitamin D metabolites. Optimal 25-hydroxyvitamin D (25(OH)D) levels remain debated. Varying recommendations from different societies arise from evaluating different clinical or public health approaches. The lack of assay standardization also poses challenges in interpreting data from available studies, hindering rational data pooling and meta-analyses. Beyond the well-known skeletal features, interest in vitamin D's extraskeletal effects has led to clinical trials on cancer, cardiovascular risk, respiratory effects, autoimmune diseases, diabetes, and mortality. The initial negative results are likely due to enrollment of vitamin D-replete individuals. Subsequent post hoc analyses have suggested, nevertheless, potential benefits in reducing cancer incidence, autoimmune diseases, cardiovascular events, and diabetes. Oral administration of vitamin D is the preferred route. Parenteral administration is reserved for specific clinical situations. Cholecalciferol is favored due to safety and minimal monitoring requirements. Calcifediol may be used in certain conditions, while calcitriol should be limited to specific disorders in which the active metabolite is not readily produced in vivo. Further studies are needed to investigate vitamin D effects in relation to the different recommended 25(OH)D levels and the efficacy of the different supplementary formulations in achieving biochemical and clinical outcomes within the multifaced skeletal and extraskeletal potential effects of vitamin D.

Agreement Between Mega-Trials and Smaller Trials: A Systematic Review and Meta-Research Analysis

Importance

Mega-trials can provide large-scale evidence on important questions.

Objective

To explore how the results of mega-trials compare with the meta-analysis results of trials with smaller sample sizes.

Data Sources

ClinicalTrials.gov was searched for mega-trials until January 2023. PubMed was searched until June 2023 for meta-analyses incorporating the results of the eligible mega-trials.

Study Selection

Mega-trials were eligible if they were noncluster nonvaccine randomized clinical trials, had a sample size over 10 000, and had a peer-reviewed meta-analysis publication presenting results for the primary outcome of the mega-trials and/or all-cause mortality.

Data Extraction and Synthesis

For each selected meta-analysis, we extracted results of smaller trials and mega-trials included in the summary effect estimate and combined them separately using random effects. These estimates were used to calculate the ratio of odds ratios (ROR) between mega-trials and smaller trials in each meta-analysis. Next, the RORs were combined using random effects. Risk of bias was extracted for each trial included in our analyses (or when not available, assessed only for mega-trials). Data analysis was conducted from January to June 2024.

Main Outcomes and Measures

The main outcomes were the summary ROR for the primary outcome and all-cause mortality between mega-trials and smaller trials. Sensitivity analyses were performed with respect to the year of publication, masking, weight, type of intervention, and specialty.

Results

Of 120 mega-trials identified, 41 showed a significant result for the primary outcome and 22 showed a significant result for all-cause mortality. In 35 comparisons of primary outcomes (including 85 point estimates from 69 unique mega-trials and 272 point estimates from smaller trials) and 26 comparisons of all-cause mortality (including 70 point estimates from 65 unique mega-trials and 267 point estimates from smaller trials), no difference existed between the outcomes of the mega-trials and smaller trials for primary outcome (ROR, 1.00; 95% CI, 0.97-1.04) nor for all-cause mortality (ROR, 1.00; 95% CI, 0.97-1.04). For the primary outcomes, smaller trials published before the mega-trials had more favorable results than the mega-trials (ROR, 1.05; 95% CI, 1.01-1.10) and subsequent smaller trials published after the mega-trials (ROR, 1.10; 95% CI, 1.04-1.18).

Conclusions and Relevance

In this meta-research analysis, meta-analyses of smaller studies showed overall comparable results with mega-trials, but smaller trials published before the mega-trials gave more favorable results than mega-trials. These findings suggest that mega-trials need to be performed more often given the relative low number of mega-trials found, their low significant rates, and the fact that smaller trials published prior to mega-trial report more beneficial results than mega-trials and subsequent smaller trials.

Vitamin D prophylaxis in persons with epilepsy?

Limited guidelines exist regarding osteoporosis prevention in the general population. Despite being a subject of controversy, the majority of research suggests that decreased vitamin D levels correlate with increased bone turnover, that is, an important risk factor for osteoporosis development. In most guidelines, daily vitamin D supplementation is recommended. In persons with epilepsy (PWE), the situation is more complex, as other factors can increase the chance of being vitamin D deficient. Currently, there are no internationally accepted guidelines regarding monitoring bone health in PWE. Our aim was to review the existing evidence in PWE on: (1) risk factors for vitamin D deficiency, (2) the identification of higher risk groups, and (3) the optimal ways to monitor bone health. Our narrative review shows that: (1) anti-seizure medication (ASM) use, especially enzyme-inducing ASM (EIASM) and valproic acid, is identified as an important risk factor for impaired bone health (e.g., increased risk for osteoporosis/fractures and/or vitamin D deficiency); (2) higher risk groups within the PWE population are present: intellectual or physical disability, institutionalized patients, puberty, early onset epilepsy and developmental epileptic encephalopathies, postmenopausal women, and use of multiple ASM/concomitant drugs (e.g. corticosteroids); and (3) a monitoring scheme can be suggested including laboratory tests, bone density measurements, managing of risk factors, and/or vitamin D supplementation. Overall, regular vitamin D measurement in PWE is a cost-effective and practical method for monitoring vitamin D deficiency, whereas in high-risk patients the combination of vitamin D measurement and bone densitometry is recommended. There is not enough evidence to advocate continuous vitamin D supplementation in all PWE. Children with epilepsy should receive the recommended daily intake of vitamin D for age and additional monitoring and supplementation if at higher risk of deficiency. There is a need for prospective trials exploring the potential benefit of vitamin D supplementation in PWE.

Real-world effectiveness and safety of combined calcium 600 mg and cholecalciferol 2000 IU for treating vitamin d deficiency: Results from a nationwide study with focus in osteoporosis

Introduction

Treatment of calcium (Ca) and vitamin D (VD) deficiency (VDD) is crucial for health, especially in bone conditions, such as low bone mineral density (BMD) and osteoporosis. Despite updates in clinical guideline recommendations, no studies have evaluated the efficacy and safety of administering 2000 IU of cholecalciferol combined with calcium. Thus, the main objective of this study was to evaluate VD levels following treatment with Ca 600 mg/ cholecalciferol 2000 IU in real-life clinical practice.

Methods

This multicenter, retrospective, observational study included 302 adult patients receiving Ca 600 mg/D3 2000 IU orodispersible tablets, daily for ≥24 weeks. The primary outcome was 25-hydroxivitamin D [25(OH)D] serum levels following treatment. Key secondary outcomes included changes in serum 25(OH)D levels and other bone metabolism (BM) parameters, safety and tolerability. The protocol was approved by a Research Ethics Committee.

Results

285 patients were evaluated (mean age [SD]: 67.4 [12.6] years old; 88.4 % women; basal serum 25(OH)D: 20.0 [8.6] ng/mL); 80.7 % reported previous history of osteoporosis/low BMD (osteopenia) and 37.2 % had received other Ca/VD prior to start study treatment. Median treatment duration was 38.5 weeks [range 24.0-82.4]. Overall, 94.4 % of patients increased serum 25(OH)D following treatment to a mean of 36.3 [11.8] ng/mL (p < 0.001 vs. baseline). Patients with basal VDD, significantly increased serum 25(OH)D to a mean over 30 ng/mL; no significant change found in repleted patients (basal 25(OH)D level ≥ 30 ng/mL). PTH was significantly reduced after treatment, with no clinically relevant effect on serum Ca or phosphate. Three non-serious treatment-emergent adverse events were reported. A post-hoc analysis on osteoporotic patients revealed virtually identical results in this population.

Conclusion

Treatment with Ca 600 mg/cholecalciferol 2000 IU for at least 24 weeks is effective and safe, especially in osteoporosis. Patients with VDD significantly increase plasma 25(OH)D to optimal range for bone health, with no clinically relevant changes on other bone metabolism parameters other than reducing secondary hyperparathyroidism. The magnitude of 25(OH)D increase directly correlates with the severity of VDD, with no effect in basally repleted patients.

Effect of vitamin D on risk of falls and fractures - The contribution of recent mega-trials

Three recently-completed, large clinical trials in the U.S, New Zealand, and Australia, referred to herein as the 'mega-trials', were conducted to determine the impact of supplemental vitamin D on a variety of outcomes including falls and fractures. The trials were similar in design and collectively included over 50,000 generally vitamin D replete, older men and women. The mega-trials established that vitamin D supplementation with the equivalent of 2000 to 3300 IU/d of vitamin D3 had no favorable effect on risk of falls or fractures. This review focuses on specific design elements of the trials and how they likely influenced these trial findings. While these trials were in progress, evidence emerged that circulating 25-hydroxyvitamin D levels have a U-shaped association with risk of falling, raising concern about a potential untoward effect of high dose supplementation. There is compelling evidence that in older, vitamin D- and calcium-insufficient nursing home residents, the combination of vitamin D and calcium in modest replacement doses dramatically reduces the risk of hip and other fractures. Community-dwelling older adults in many populous countries around the globe have widespread vitamin D and calcium insufficiency. It is time to follow the evidence trail and determine the effect of vitamin D and calcium replacement on their risk of falls and fractures.

Stanniocalcin 1 and 1,25-dihydroxyvitamin D3 cooperatively regulate bone mineralization by osteoblasts

Stanniocalcin 1 (STC1) is a calcium- and phosphate-regulating hormone that is expressed in all tissues, including bone tissues, and is involved in calcium and phosphate homeostasis. Previously, STC1 expression was found to be increased by 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] administration in renal proximal tubular cells. In this study, we investigated whether STC1 directly regulates osteoblast differentiation or reciprocally controls the effects of 1,25(OH)2D3 on osteoblasts to contribute to bone homeostasis. We found that STC1 inhibited osteoblast differentiation in vitro and bone morphogenetic protein 2 (BMP2)-induced ectopic bone formation in vivo. Moreover, 1,25(OH)2D3 increased STC1 expression through direct binding to the Stc1 promoter of the vitamin D receptor (VDR). STC1 activated the 1,25(OH)2D3-VDR signaling pathway through the upregulation of VDR expression mediated by the inhibition of Akt phosphorylation in osteoblasts. STC1 further increased the effects of 1,25(OH)2D3 on receptor activator of nuclear factor-κB ligand (RANKL) secretion and inhibited osteoblast differentiation by exhibiting a positive correlation with 1,25(OH)2D3. The long-bone phenotype of transgenic mice overexpressing STC1 specifically in osteoblasts was not significantly different from that of wild-type mice. However, compared with that in the wild-type mice, 1,25(OH)2D3 administration significantly decreased bone mass in the STC1 transgenic mice. Collectively, these results suggest that STC1 negatively regulates osteoblast differentiation and bone formation; however, the inhibitory effect of STC1 on osteoblasts is transient and can be reversed under normal conditions. Nevertheless, the synergistic effect of STC1 and 1,25(OH)2D3 through 1,25(OH)2D3 administration may reduce bone mass by inhibiting osteoblast differentiation.

Zoledronic acid for hip fracture during initial hospitalization

Inpatient zoledronic acid (IP-ZA) administered during the initial fracture hospitalization significantly improves the osteoporosis treatment rate. Clinical outcomes of IP-ZA after hip fracture remain uncertain. Here we report a cohort study that emulated a randomized controlled trial using real-world data and evaluated the risk of all-cause-mortality and radiologically confirmed subsequent new fractures among patients hospitalized for a hip fracture who had received IP-ZA as compared with propensity-matched controls. A total of 654 patients who had received IP-ZA and 6877 controls (for whom anti-osteoporosis treatment was indicated but no IP-ZA started during index hospitalization) were included in the study. The primary cohort comprised 652 IP-ZA patients (IP-ZA group) and 1926 matched controls (untreated group), with 71.7% female 92.1% White participants, with a mean age of 80.9 years. Cumulative all-cause mortality over the 24-month follow-up for the IP-ZA group was 12.3% and 20.7% for the untreated group (hazard ratio [HR], 0.62; 95% CI, 0.49-0.78, p < .001). A total of 585 (89.7%) patients in IP-ZA group received only a single dose of ZA during the 24 months, and the death rate of this single dose group was 13.3%, which was significantly lower than that of the untreated group (HR, 0.70; 95% CI, 0.55-0.89, p = .003). Rates of radiologically confirmed cumulative subsequent new vertebral fractures were 2.0% in the IP-ZA group and 5.4% in the untreated group (HR, 0.40; 95% CI, 0.22-0.71, p = .001). A similarly lower rate of new vertebral fractures was seen in the single dose subgroup (1.9% vs 5.4%; HR, 0.44; 95% 0.24-0.82, p = .008). IP-ZA, administered during the initial hospitalization for hip fracture, was associated with lower all-cause-mortality and risk of radiologically confirmed subsequent new vertebral fractures, and thus offers a mechanism to narrow the treatment gap in patients having sustained a hip fragility fracture.

Confronting the global obesity epidemic: investigating the role and underlying mechanisms of vitamin D in metabolic syndrome management

The escalating prevalence of MetS, driven by global obesity trends, underscores the urgent need for innovative therapeutic strategies. To gain a deeper understanding of the therapeutic potential of vitamin D in addressing MetS, we embarked on a targeted literature review that thoroughly examines the scientific underpinnings and pivotal discoveries derived from pertinent studies, aiming to unravel the intricate mechanisms through which vitamin D exerts its effects on MetS and its components. This article explores the multifunctional role of vitamin D in the management of MetS, focusing on its regulatory effects on insulin sensitivity, lipid metabolism, inflammation, and immune response. Through an extensive review of current research, we unveil the complex mechanisms by which vitamin D influences MetS components, highlighting its potential as a therapeutic agent. Our analysis reveals that vitamin D's efficacy extends beyond bone health to include significant impacts on cellular and molecular pathways critical to MetS. We advocate for further research to optimize vitamin D supplementation as a component of precision medicine for MetS, considering the safety concerns related to dosage and long-term use.

Sunlight: Time for a Rethink?

UVR is a skin carcinogen, yet no studies link sun exposure to increased all-cause mortality. Epidemiological studies from the United Kingdom and Sweden link sun exposure with reduced all-cause, cardiovascular, and cancer mortality. Vitamin D synthesis is dependent on UVB exposure. Individuals with higher serum levels of vitamin D are healthier in many ways, yet multiple trials of oral vitamin D supplementation show little benefit. Growing evidence shows that sunlight has health benefits through vitamin D-independent pathways, such as photomobilization of nitric oxide from cutaneous stores with reduction in cardiovascular morbidity. Sunlight has important systemic health benefit as well as risks.

Effects of walnut consumption for 2 years on older adults' bone health in the Walnuts and Healthy Aging (WAHA) trial

BACKGROUND

Nutritional strategies to maintain bone health in aging individuals are of great interest. Given the beneficial nutrient composition of walnuts, rich in alpha-linolenic (the vegetable n-3 fatty acid) and polyphenols, their regular consumption might be a dietary option to reduce age-related bone loss. We determined whether daily walnut consumption improves bone mineral density (BMD) and circulating biomarkers of bone turnover.

METHODS

The Walnuts and Healthy Aging study (WAHA) is a two-center, parallel, randomized controlled trial evaluating the effect of a diet enriched with walnuts at ≈15% energy compared with a control diet for 2 years on age-related health outcomes in healthy men and women aged 63-79 years. Changes in BMD were a prespecified secondary outcome only at the Barcelona node of the trial, where 352 participants were randomized. Retention rate was 92.6%. Primary endpoints were 2-year changes in BMD at the spine and the nondominant femoral neck, determined by dual-energy X-ray absorptiometry (DXA). Secondary endpoints were 2-year changes in bone turnover biomarkers (adrenocorticotropic hormone, Dickkopf WNT signaling pathway inhibitor-1, osteoprotegerin, osteocalcin, osteopontin, sclerostin, parathyroid hormone, and fibroblast growth factor-23), which were quantified in 211 randomly selected participants.

RESULTS

The walnut diet versus the control diet had no effect on 2-year changes in BMD at the spine (0.15% vs. 0.35%, p = 0.632) and femoral neck (-0.90% vs. -0.70%, p = 0.653), or on bone turnover biomarkers. Results were similar in participants treated or not with bone resorption inhibitors or those with or without osteoporosis/osteopenia at inclusion.

CONCLUSIONS

Compared with the usual diet, a diet enriched with walnuts at 15% of energy for 2 years failed to improve BMD or circulating markers of bone metabolism in healthy older people.

Vitamin D therapy in chronic kidney disease: a critical appraisal of clinical trial evidence

In people with chronic kidney disease (CKD), the physiology of vitamin D is altered and leads to abnormalities in bone and mineral metabolism which contribute to CKD mineral and bone disorder (CKD-MBD). Observational studies show an association between vitamin D deficiency and increased risk of mortality, cardiovascular disease and fracture in CKD. Although vitamin D therapy is widely prescribed in people with CKD, clinical trials to date have failed to demonstrate a clear benefit of either nutritional vitamin D supplementation or active vitamin D therapy in improving clinical outcomes in CKD. This review provides an updated critical analysis of recent trial evidence on vitamin D therapy in people with CKD.

Effects of vitamin D3, omega-3s, and a simple strength training exercise program on bone health: the DO-HEALTH randomized controlled trial

Evidence on the effects of Vitamin D, omega-3s, and exercise on areal bone mineral density (aBMD) in healthy older adults is limited. We examined whether vitamin D3, omega-3s, or a simple home-based exercise program (SHEP), alone or in combination, over 3 years, improve lumbar spine (LS), femoral neck (FN), or total hip (TH) aBMD assessed by DXA. Areal BMD was a secondary outcome in DO-HEALTH, a 3-year, multicenter, double-blind, randomized 2 × 2 × 2 factorial design trial in generally healthy older adults age ≥ 70 years. The study interventions were vitamin D3 (2000IU/d), omega-3s (1 g/d), and SHEP (3 × 30 min/wk), applied alone or in combination in eight treatment arms. Mixed effects models were used, adjusting for age, sex, BMI, prior fall, study site, and baseline level of the outcome. Main effects were assessed in the absence of an interaction between the interventions. Subgroup analyses by age, sex, physical activity level, dietary calcium intake, serum 25(OH)D levels, and fracture history were conducted. DXA scans were available for 1493 participants (mean age 75 years; 80.4% were physically active, 44% had 25(OH)D levels <20 ng/mL). At the LS and FN sites, none of the treatments showed a benefit. At the TH, vitamin D versus no vitamin D treatment showed a significant benefit across 3 years (difference in adjusted means [AM]: 0.0035 [95% CI, 0.0011, 0.0059] g/cm). Furthermore, there was a benefit for vitamin D versus no vitamin D treatment on LS aBMD in the male subgroup (interaction P = .003; ∆AM: 0.0070 [95% CI, 0.0007, 0.0132] g/cm). Omega-3s and SHEP had no benefit on aBMD in healthy, active, and largely vitamin D replete older adults. Our study suggests a small benefit of 2000 IU vitamin D daily on TH aBMD overall and LS aBMD among men; however, effect sizes were very modest and the clinical impact of these findings is unclear.

Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline

BACKGROUND

Numerous studies demonstrate associations between serum concentrations of 25-hydroxyvitamin D (25[OH]D) and a variety of common disorders, including musculoskeletal, metabolic, cardiovascular, malignant, autoimmune, and infectious diseases. Although a causal link between serum 25(OH)D concentrations and many disorders has not been clearly established, these associations have led to widespread supplementation with vitamin D and increased laboratory testing for 25(OH)D in the general population. The benefit-risk ratio of this increase in vitamin D use is not clear, and the optimal vitamin D intake and the role of testing for 25(OH)D for disease prevention remain uncertain.

OBJECTIVE

To develop clinical guidelines for the use of vitamin D (cholecalciferol [vitamin D3] or ergocalciferol [vitamin D2]) to lower the risk of disease in individuals without established indications for vitamin D treatment or 25(OH)D testing.

METHODS

A multidisciplinary panel of clinical experts, along with experts in guideline methodology and systematic literature review, identified and prioritized 14 clinically relevant questions related to the use of vitamin D and 25(OH)D testing to lower the risk of disease. The panel prioritized randomized placebo-controlled trials in general populations (without an established indication for vitamin D treatment or 25[OH]D testing), evaluating the effects of empiric vitamin D administration throughout the lifespan, as well as in select conditions (pregnancy and prediabetes). The panel defined "empiric supplementation" as vitamin D intake that (a) exceeds the Dietary Reference Intakes (DRI) and (b) is implemented without testing for 25(OH)D. Systematic reviews queried electronic databases for publications related to these 14 clinical questions. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and guide recommendations. The approach incorporated perspectives from a patient representative and considered patient values, costs and resources required, acceptability and feasibility, and impact on health equity of the proposed recommendations. The process to develop this clinical guideline did not use a risk assessment framework and was not designed to replace current DRI for vitamin D.

RESULTS

The panel suggests empiric vitamin D supplementation for children and adolescents aged 1 to 18 years to prevent nutritional rickets and because of its potential to lower the risk of respiratory tract infections; for those aged 75 years and older because of its potential to lower the risk of mortality; for those who are pregnant because of its potential to lower the risk of preeclampsia, intra-uterine mortality, preterm birth, small-for-gestational-age birth, and neonatal mortality; and for those with high-risk prediabetes because of its potential to reduce progression to diabetes. Because the vitamin D doses in the included clinical trials varied considerably and many trial participants were allowed to continue their own vitamin D-containing supplements, the optimal doses for empiric vitamin D supplementation remain unclear for the populations considered. For nonpregnant people older than 50 years for whom vitamin D is indicated, the panel suggests supplementation via daily administration of vitamin D, rather than intermittent use of high doses. The panel suggests against empiric vitamin D supplementation above the current DRI to lower the risk of disease in healthy adults younger than 75 years. No clinical trial evidence was found to support routine screening for 25(OH)D in the general population, nor in those with obesity or dark complexion, and there was no clear evidence defining the optimal target level of 25(OH)D required for disease prevention in the populations considered; thus, the panel suggests against routine 25(OH)D testing in all populations considered. The panel judged that, in most situations, empiric vitamin D supplementation is inexpensive, feasible, acceptable to both healthy individuals and health care professionals, and has no negative effect on health equity.

CONCLUSION

The panel suggests empiric vitamin D for those aged 1 to 18 years and adults over 75 years of age, those who are pregnant, and those with high-risk prediabetes. Due to the scarcity of natural food sources rich in vitamin D, empiric supplementation can be achieved through a combination of fortified foods and supplements that contain vitamin D. Based on the absence of supportive clinical trial evidence, the panel suggests against routine 25(OH)D testing in the absence of established indications. These recommendations are not meant to replace the current DRIs for vitamin D, nor do they apply to people with established indications for vitamin D treatment or 25(OH)D testing. Further research is needed to determine optimal 25(OH)D levels for specific health benefits.

A Systematic Review Supporting the Endocrine Society Clinical Practice Guidelines on Vitamin D

CONTEXT

Low vitamin D status is common and is associated with various common medical conditions.

OBJECTIVE

To support the development of the Endocrine Society's Clinical Practice Guideline on Vitamin D for the Prevention of Disease.

METHODS

We searched multiple databases for studies that addressed 14 clinical questions prioritized by the guideline panel. Of the 14 questions, 10 clinical questions assessed the effect of vitamin D vs no vitamin D in the general population throughout the lifespan, during pregnancy, and in adults with prediabetes; 1 question assessed dosing; and 3 questions addressed screening with serum 25-hydroxyvitamin D (25[OH]D). The Grading of Recommendations Assessment, Development and Evaluation approach was used to assess certainty of evidence.

RESULTS

Electronic searches yielded 37 007 citations, from which we included 151 studies. In children and adolescents, low-certainty evidence suggested reduction in respiratory tract infections with empiric vitamin D. There was no significant effect on select outcomes in healthy adults aged 19 to 74 years with variable certainty of evidence. There was a very small reduction in mortality among adults older than 75 years with high certainty of evidence. In pregnant women, low-certainty evidence suggested possible benefit on various maternal, fetal, and neonatal outcomes. In adults with prediabetes, moderate certainty of evidence suggested reduction in the rate of progression to diabetes. Administration of high-dose intermittent vitamin D may increase falls, compared to lower-dose daily dosing. We did not identify trials on the benefits and harms of screening with serum 25(OH)D.

CONCLUSION

The evidence summarized in this systematic review addresses the benefits and harms of vitamin D for the prevention of disease. The guideline panel considered additional information about individuals' and providers' values and preferences and other important decisional and contextual factors to develop clinical recommendations.

Vitamin D Insufficiency and Epistemic Humility: An Endocrine Society Guideline Communication

A long-held precept is that vitamin D supplementation primarily, if not exclusively, benefits individuals with low circulating 25-hydroxyvitamin D (25[OH]D) concentrations at baseline. However, the most appropriate 25(OH)D threshold to distinguish unacceptably low vs reliably adequate concentrations remains controversial. Such threshold proposals have largely been based on observational studies, which provide less robust evidence compared to randomized clinical trials (RCTs). Since the Endocrine Society's first vitamin D-related guideline was published in 2011, several large vitamin D-related RCTs have been published, and a newly commissioned guideline development panel (GDP) prioritized 4 clinical questions related to the benefits and harms of vitamin D supplementation in generally healthy individuals with 25(OH)D levels below a threshold. The GDP determined that available clinical trial evidence does not permit the establishment of 25(OH)D thresholds that specifically predict meaningful benefit with vitamin D supplementation. The panel noted important limitations in the available evidence, and the panel's overall certainty in the available evidence was very low. Nonetheless, based on the GDP's analyses and judgments, the Endocrine Society no longer endorses its previously proposed definition of vitamin D "sufficiency" (ie, at least 30 ng/mL [75 nmol/L]) or its previously proposed definition of vitamin D "insufficiency" (ie, greater than 20 ng/mL [50 nmol/L] but lower than 30 ng/mL [75 nmol/L]). The Endocrine Society's rationale for such is the subject of this Guideline Communication.

Obesity and the obesity paradox in abdominal aortic aneurysm

Obesity, characterized by its complexity and heterogeneity, has emerged as a significant public health concern. Its association with increased incidence and mortality of cardiovascular diseases stems not only from its complications and comorbidities but also from the endocrine effects of adipose tissue. Abdominal aortic aneurysm (AAA), a chronic inflammatory condition, has been closely linked to obesity. Intriguingly, mild obesity appears to confer a protective effect against AAA mortality, whereas severe obesity and being underweight do not, giving rise to the concept of the "obesity paradox". This review aims to provide an overview of obesity and its paradoxical relationship with AAA, elucidate its underlying mechanisms, and discuss the importance of preoperative weight loss in severely obese patients with AAA.

Incidence of four major osteoporotic fragility fractures among older individuals in Sado, Japan, in 2020

INTRODUCTION

This study compared the 2020 incidence of fragility fractures in Sado City with those from 2004 to 2015.

MATERIALS AND METHODS

Data from patients aged ≥ 60 years living in Sado City with fragility fractures in the hip, vertebral, distal radius, and proximal humerus between January 1 and December 31, 2020, were collected. We examined the number and incidence of four types of osteoporotic fractures in the older population aged ≥ 60 years living in Sado City in 2020. We compared the results with those of the 2004, 2010, and 2015 surveys, examining the temporal change and trend in the incidence of the four fracture types in this population. We investigated the use rate of anti-osteoporotic medications and the relationship between their administration and the occurrence of fragility fractures.

RESULTS

The age-specific incidence of hip fractures slightly decreased from 2015. However, the incidence of the other three fractures slightly increased, although the difference was not statistically significant. The incidence of hip fractures markedly increased in the 80 s. In 2020, the percentage of patients taking anti-osteoporotic agents before the occurrence of fractures decreased to 12.4% from 14.5% in 2015; it increased from 4% in 2004 to 7.6% in 2010.

CONCLUSION

The 2020 incidence of the four fractures did not decrease, and the percentage of patients receiving anti-osteoporotic agents did not increase. A higher frequency of osteoporosis treatment is necessary to reduce the incidence of fragility fractures. We recommend using anti-osteoporotic agents to prevent hip fractures among individuals in their mid-70 s and above.

Value of Vitamin D Metabolite Ratios in 3 Patients as Diagnostic Criteria to Assess Vitamin D Status

Although clinical guidelines recommend measuring total plasma 25-hydroxyvitamin D (25[OH]D) to assess vitamin D (VitD) status, this index does not account for 3-fold inter-individual variation in VitD binding protein (VDBP) level. We present 3 individuals with total plasma 25(OH)D levels of 10.8 to 12.3 ng/mL (27-30.7 nmol/L). Because Endocrine Society guidelines define VitD deficiency as 25(OH)D ≤ 20 ng/mL (50 nmol/L), all 3 would be judged to be VitD deficient. VitD3 supplementation increased 25(OH)D to the range of 31.7 to 33.8 ng/mL (79.1-84.4 nmol/L). Patient #1 exhibited secondary hyperparathyroidism; VitD3 supplementation decreased parathyroid hormone (PTH) by 34% without a clinically significant change in PTH levels in the other 2 individuals. Thus, 25(OH)D level did not distinguish between the 1 patient who had secondary hyperparathyroidism and the 2 who did not. We therefore inquired whether VitD metabolite ratios (which are VDBP-independent) might distinguish among these 3 individuals. Of all the assessed ratios, the 1,25(OH)2D/24,25(OH)2D ratio was the most informative, which had a value of 102 pg/ng in the individual with secondary hyperparathyroidism but lower values (41 and 20 pg/ng) in the other 2 individuals. These cases illustrate the value of the 1,25(OH)2D/24,25(OH)2D ratio to provide clinically relevant information about VitD status.

Postoperative Vitamin D Surveillance and Supplementation in Revision Total Knee Arthroplasty Patients: A Retrospective Cohort Analysis

This study was a retrospective cohort analysis of 20 patients who underwent 23 revision total knee arthroplasty procedures in a single geographic region of the United States from January 2015 to February 2023. We analyzed their 25-OH vitamin D levels preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and 2 years. We categorized their supplementation regimens by dose: none, low dose (1000 IU and below), medium dose (1001-5000 IU), and high dose (>5000 IU). We found that there was a high incidence of vitamin D deficiency in this patient population.

Native vitamin D in CKD and renal transplantation: meaning and rationale for its supplementation

Chronic kidney disease (CKD) poses a significant epidemiological challenge, necessitating effective patient management strategies. Nutritional intervention, particularly vitamin D supplementation, has garnered attention for its potential therapeutic utility in CKD. Despite widespread acknowledgment of the importance of vitamin D, particularly in bone and mineral metabolism, its supplementation in CKD patients for non-skeletal purposes remains contentious due to limited evidence. Hypovitaminosis D linked with CKD substantially contributes to disturbances in mineral and bone metabolism, increasing the risks of cardiovascular complications and skeletal disorders. Notably, CKD patients experience progressive vitamin D deficiency, exacerbating as the disease progresses. Guidelines recommend monitoring 25-hydroxyvitamin D (25 (OH)-D) levels due to their correlation with mineral metabolism parameters, although robust evidence for recommending supplementation is lacking. The primary aim of this paper is to focus on the main open questions regarding vitamin D supplementation in CKD, reporting the current evidence concerning the role of vitamin D supplementation in CKD and in renal transplant recipients.

Relationship Between Serum 25-Hydroxyvitamin D and Bone Mineral Density, Fracture Risk, and Bone Metabolism in Adults With Osteoporosis/Fractures

OBJECTIVE

To evaluate the association of serum 25-hydroxyvitamin D (25(OH) D) levels with bone mineral density (BMD), fracture risk, and bone metabolism.

METHODS

This multicenter cross-sectional study recruited menopausal females and males greater than or equal to 50 year old with osteoporosis/fractures between September 2016 and September 2021. Assessment included clinical data, 25(OH)D, intact parathyroid hormone (iPTH), procollagen type 1 amino-terminal propeptide (P1NP), carboxy-terminal collagen crosslinks (CTX), lateral thoracolumbar spine x-rays, and BMD.

RESULTS

A total of 3003 individuals were stratified by 25(OH) D levels: 720 individuals (24%) <20 ng/mL, 1338 individuals (44.5%) 20 to 29 ng/mL, and 945 individuals (31.5%) ≥30 ng/mL. In unadjusted and multivariable models, BMD T-score, except spine, was significantly and positively associated with 25(OH)D levels. 25(OH) D levels were inversely associated with Fracture Risk Assessment Tool scores. Patients with 25(OH)D <20 ng/mL had significantly higher iPTH and bone turnover markers (P1NP and CTX) than patients with 25(OH)D ≧20 ng/mL in all models. When analyzing bone-related markers and BMD, total hip and femoral neck BMD T-scores were positively correlated with 25(OH)D concentrations and BMI but negatively correlated with iPTH, P1NP, CTX, and age. In multivariate models with all bone-related markers, only 25(OH)D levels were significantly associated with total hip and femoral neck BMD.

CONCLUSION

Vitamin D deficiency is significantly associated with decreased total hip and femoral neck BMD and increased fracture risk as assessed by Fracture Risk Assessment Tool. In those with osteoporosis/fractures, vitamin D is implicated in the causal relationship between bone remodeling and BMD. Assessing vitamin D status is imperative for those at risk for osteoporosis/fractures.

Secondary hyperparathyroidism: Predictors and relationship with vitamin D status, bone turnover markers and bone mineral density

INTRODUCTION

Secondary hyperparathyroidism (SHPT) has adverse implications for bone health but is relatively understudied. In this study we examine the prevalence and determinants of SHPT and describe the relationship of SHPT with bone turnover markers and bone mineral density (BMD) in older Irish adults.

METHOD

Eligible participants (n = 4139) were identified from the Trinity-Ulster-Department of Agriculture (TUDA) study, a cohort of Irish adults aged ≥60 years. Exclusion criteria included an estimated glomerular filtration rate (eGFR) <30 ml/min and serum calcium >2.5 mmol/l to remove hyperparathyroidism due to advanced chronic kidney disease (CKD) and primary hyperparathyroidism respectively. The relationship between SHPT and bone turnover markers and BMD (measured by densitometry) was examined in a subsample (n = 1488). Vitamin D deficiency was defined as 25-hydroxyvitamin D [25 (OH)D] <30 nmol/l.

RESULTS

Participants had a mean age of 73.6 ± 7.9 years, 65.1 % were female and 19.4 % were found to be vitamin D deficient. The prevalence of SHPT decreased as vitamin D increased, from 30.6 % in those deficient to 9.8 % in those with 25(OH)D ≥ 50 nmol/l and increased with declining kidney function. In non‑calcium supplement users, principal determinants of SHPT were vitamin D deficiency (OR 4.18, CI 3.05-5.73, p < 0.001), eGFR 30-44 ml/min (OR 3.69, CI 2.44-5.57, p < 0.001), loop diuretic use (OR 3.52, CI 2.59-4.79, p < 0.001) and to a lesser extent body mass index (p = 0.001), eGFR 45-59 ml/min (p < 0.001) and 25(OH)D level 30-49 nmol/l (p = 0.002). Similar findings were observed in calcium supplement users, though proton pump inhibitors were also associated with SHPT (OR 1.55, CI 1.08-2.22, p = 0.018) while vitamin D 30-49 nmol/l was not. In participants with SHPT versus those without, bone turnover markers were higher: bone alkaline phosphatase (p = 0.017) and tartrate-resistant acid phosphatase (p = 0.033), whilst there was lower BMD at the neck of femur (0.880 vs. 0.903 g/cm2, p = 0.033) and total hip (0.968 vs. 0.995 g/cm2, P = 0.017).

DISCUSSION

The results show that up to one in six older Irish adults had SHPT and this was associated with lower BMD and higher concentrations of bone turnover markers. Both vitamin D deficiency and 25(OH)D level 30-49 nmol/l were important predictors of SHPT. Loop diuretics and PPIs may also increase the risk of SHPT, and their use may need to be carefully considered in this population. Further studies examining the potential impact of these factors on bone health in similar populations to our study sample are warranted.

Hormonal Control of Bone Architecture Throughout the Lifespan: Implications for Fracture Prediction and Prevention

BACKGROUND

Skeletal modeling in childhood and adolescence and continuous remodeling throughout the lifespan are designed to adapt to a changing environment and resist external forces and fractures. The flux of sex steroids in men and women, beginning from fetal development and evolving through infancy, childhood, puberty, young adulthood, peri/menopause transition, and postmenopause, is critical for bone size, peak bone mass, and fracture resistance.

OBJECTIVE

This review will highlight how changes in sex steroids throughout the lifespan affect bone cells and the consequence of these changes on bone architecture and strength.

METHODS

Literature review and discussion.

RESULTS

The contributions of estrogen and testosterone on skeletal development have been difficult to study due to the reciprocal and intertwining contributions of one on the other. Although orchiectomy in men renders circulating testosterone absent, circulating estrogen also declines due to testosterone being the substrate for estradiol. The discovery of men with absent estradiol or resistance to estrogen and the study of mouse models led to the understanding that estrogen has a larger direct role in skeletal development and maintenance in men and women. The mechanistic reason for larger bone size in men is incompletely understood but related to indirect effects of testosterone on the skeleton, such as higher muscle mass leading to larger mechanical loading. Declines in sex steroids during menopause in women and androgen deprivation therapies in men have profound and negative effects on the skeleton. Therapies to prevent such bone loss are available, but how such therapies can be tailored based on bone size and architecture remains an area of investigation.

CONCLUSION

In this review, the elegant interplay and contribution of sex steroids on bone architecture in men and women throughout the lifespan is described.

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

INTRODUCTION

These guidelines aim to provide evidence-based recommendations for the supplementation of Vitamin D in maintaining bone health. An unmet need persists in Latin American regarding the availability of clinical and real-world data for rationalizing the use of vitamin D supplementation. The objective of these guidelines is to establish clear and practical recommendations for healthcare practitioners from Latin American countries to address Vitamin D insufficiency in clinical practice.

METHODS

The guidelines were developed according to the GRADE-ADOLOPMENT methodology for the adaptation or adoption of CPGs or evidence-based recommendations. A search for high quality CPGs was complemented through a comprehensive review of recent literature, including randomized controlled trials, observational studies, and systematic reviews evaluating the effects of Vitamin D supplementation on bone health. The evidence to decision framework proposed by the GRADE Working Group was implemented by a panel of experts in endocrinology, bone health, and clinical research.

RESULTS

The guidelines recommend Vitamin D supplementation for individuals aged 18 and above, considering various populations, including healthy adults, individuals with osteopenia, osteoporosis patients, and institutionalized older adults. These recommendations offer dosing regimens depending on an individualized treatment plan, and monitoring intervals of serum 25-hydroxyvitamin D levels and adjustments based on individual results.

DISCUSSION

The guidelines highlight the role of Vitamin D in bone health and propose a standardized approach for healthcare practitioners to address Vitamin D insufficiency across Latin America. The panel underscored the necessity for generating local data and stressed the importance of considering regional geography, social dynamics, and cultural specificities when implementing these guidelines.

Nutrition, Vitamin D, and Calcium in Elderly Patients before and after a Hip Fracture and Their Impact on the Musculoskeletal System: A Narrative Review

Hip fractures are a major health issue considerably impacting patients' quality of life and well-being. This is particularly evident in elderly subjects, in which the decline in bone and muscle mass coexists and predisposes individuals to fall and fracture. Among interventions to be implemented in hip fractured patients, the assessment and management of nutritional status is pivotal, particularly in subjects older than 65. Nutrition plays a central role in both primary and secondary preventions of fracture. An adequate protein intake improves muscle mass and strength and the intestinal absorption of calcium. Other nutrients with recognized beneficial effects on bone health are calcium, vitamins D, K, and C, potassium, magnesium, folate, and carotenoids. With reference to calcium, results from longitudinal studies showed that the consumption of dairy foods has a protective role against fractures. Moreover, the most recent systematic reviews and meta-analyses and one umbrella review demonstrated that the combination of calcium and vitamin D supplementation significantly reduces hip fracture risk, with presumed higher efficacy in older and institutionalized subjects. Owing to these reasons, the adequate intake of calcium, vitamin D, protein, and other macro and micronutrients has been successfully implemented in the Fracture Liaison Services (FLSs) that represent the most reliable model of management for hip fracture patients. In this narrative review, papers (randomized controlled trials, prospective and intervention studies, and systematic reviews) retrieved by records from three different databases (PubMed, Embase, and Medline) have been analyzed, and the available information on the screening, assessment, and management of nutritional and vitamin D status and calcium intake in patients with hip fractures is presented along with specific prevention and treatment measures.

Continuing benefits of the Montreal Protocol and protection of the stratospheric ozone layer for human health and the environment

The protection of Earth's stratospheric ozone (O3) is an ongoing process under the auspices of the universally ratified Montreal Protocol and its Amendments and adjustments. A critical part of this process is the assessment of the environmental issues related to changes in O3. The United Nations Environment Programme's Environmental Effects Assessment Panel provides annual scientific evaluations of some of the key issues arising in the recent collective knowledge base. This current update includes a comprehensive assessment of the incidence rates of skin cancer, cataract and other skin and eye diseases observed worldwide; the effects of UV radiation on tropospheric oxidants, and air and water quality; trends in breakdown products of fluorinated chemicals and recent information of their toxicity; and recent technological innovations of building materials for greater resistance to UV radiation. These issues span a wide range of topics, including both harmful and beneficial effects of exposure to UV radiation, and complex interactions with climate change. While the Montreal Protocol has succeeded in preventing large reductions in stratospheric O3, future changes may occur due to a number of natural and anthropogenic factors. Thus, frequent assessments of potential environmental impacts are essential to ensure that policies remain based on the best available scientific knowledge.

Vitamin D and bone health: What vitamin D can and cannot do

Historically vitamin D deficiency had devastating consequences for children causing rickets resulting in severe bone deformities often leading to death. The mystery of the cause of rickets finally came to light when it was observed that cod liver oil and sunlight could prevent and cure rickets. The first vitamin D to be discovered was vitamin D2 from ergosterol in ultraviolet irradiated yeast. Vitamin D3 was discovered from UV exposure to the skin. Investigations revealed the two major functions of vitamin D were to increase intestinal calcium and phosphate absorption and mobilize calcium from the skeleton to maintain calcium and phosphorus homeostasis. Later studies demonstrated that vitamin D does not have an active role in bone mineralization. Vitamin D deficiency results in secondary hyperparathyroidism increasing bone resorption. As a result, this decreases bone mineral content and compromises the architectural integrity increasing risk for fracture. Vitamin D deficiency has also been shown to enhance aging of the bone causing cracks and enhancing bone fractures. Vitamin D deficiency also causes osteomalacia. Therefore, vitamin D sufficiency is extremely important to maximize bone health throughout life. It helps to prevent bone loss, but it cannot restore bone loss due to increased bone resorption that can occur under a variety of circumstances including menopause. The Endocrine Society Guidelines recommends for all ages that adequate vitamin D obtained from the sun, foods and supplements is necessary in order to maintain a circulating concentration of 25-hydroxyvitamin D of at least 30 ng/mL for maximum bone health.

Cancer nutritional-immunotherapy with NIR-II laser-controlled ATP release based on material repurposing strategy

Enlightened by the great success of the drug repurposing strategy in the pharmaceutical industry, in the current study, material repurposing is proposed where the performance of carbonyl iron powder (CIP), a nutritional intervention agent of iron supplement approved by the US FDA for iron deficiency anemia in clinic, was explored in anti-cancer treatment. Besides the abnormal iron metabolic characteristics of tumors, serving as potential targets for CIP-based cancer therapy under the repurposing paradigm, the efficacy of CIP as a catalyst in the Fenton reaction, activator for dihydroartemisinin (DHA), thus increasing the chemo-sensitivity of tumors, as well as a potent agent for NIR-II photothermal therapy (PTT) was fully evaluated in an injectable alginate hydrogel form. The CIP-ALG gel caused a rapid temperature rise in the tumor site under NIR-II laser irradiation, leading to complete ablation in the primary tumor. Further, this photothermal-ablation led to the significant release of ATP, and in the bilateral tumor model, both primary tumor ablation and inhibition of secondary tumor were observed simultaneously under the synergistic tumor treatment of nutritional-photothermal therapy (NT/PTT). Thus, material repurposing was confirmed by our pioneering trial and CIP-ALG-meditated NT/PTT/immunotherapy provides a new choice for safe and efficient tumor therapy.

[Resolution of the national interdisciplinary council of experts "High-dose vitamin D (Devilam) in the practice of an obstetrician-gynecologist"]

On March 28, 2024, the Council of Experts "High-dose vitamin D (Devilam) in the practice of obstetrician-gynecologist, gynecologist and endocrinologist" was held in Moscow with the participation of leading experts gynecologists, endocrinologists and obstetricians-gynecologists, during which new possibilities for the use of high-dose vitamin D in patients of various ages who need correction of existing vitamin D deficiency or insufficiency.

Risk factors for hip and vertebral fractures in chronic kidney disease: the CRIC study

Fracture risk is high in chronic kidney disease (CKD) and underlying pathophysiology and risk factors may differ from the general population. In a cohort study of 3939 participants in the chronic renal insufficiency cohort (CRIC), we used Cox regression to test associations of putative risk factors with the composite of first hip or vertebral fracture assessed using hospital discharge codes. Mean age was 58 years, 45% were female, 42% were Black, and 13% were Hispanic. There were 82 hip and 24 vertebral fractures over a mean (SD) 11.1 (4.8) years (2.4 events per 1000 person-years [95% CI: 2.0, 2.9]). Measured at baseline, diabetes, lower body mass index (BMI), steroid use, proteinuria, and elevated parathyroid hormone (PTH) were each associated with fracture risk after adjusting for covariates. Lower time-updated estimated glomerular filtration rate (eGFR) was associated with fractures (HR 1.20 per 10 mL/min/1.73m2 lower eGFR; 95% CI: 1.04, 1.38) as were lower time-updated serum calcium and bicarbonate concentrations. Among time-updated categories of kidney function, hazard ratios (95% CI) for incident fracture were 4.53 (1.77, 11.60) for kidney failure treated with dialysis and 2.48 (0.86, 7.14) for post-kidney transplantation, compared with eGFR ≥60. Proton pump inhibitor use, dietary calcium intake, measures of vitamin D status, serum phosphate, urine calcium and phosphate, and plasma fibroblast growth factor-23 were not associated with fracture risk. In conclusion, lower eGFR in CKD is associated with higher fracture risk, which was highest in kidney failure. Diabetes, lower BMI, steroid use, proteinuria, higher serum concentrations of PTH, and lower calcium and bicarbonate concentrations were associated with fractures and may be modifiable risk factors.

Vitamin D and human health: evidence from Mendelian randomization studies

We summarized the current evidence on vitamin D and major health outcomes from Mendelian randomization (MR) studies. PubMed and Embase were searched for original MR studies on vitamin D in relation to any health outcome from inception to September 1, 2022. Nonlinear MR findings were excluded due to concerns about the validity of the statistical methods used. A meta-analysis was preformed to synthesize study-specific estimates after excluding overlapping samples, where applicable. The methodological quality of the included studies was evaluated according to the STROBE-MR checklist. A total of 133 MR publications were eligible for inclusion in the analyses. The causal association between vitamin D status and 275 individual outcomes was examined. Linear MR analyses showed genetically high 25-hydroxyvitamin D (25(OH)D) concentrations were associated with reduced risk of multiple sclerosis incidence and relapse, non-infectious uveitis and scleritis, psoriasis, femur fracture, leg fracture, amyotrophic lateral sclerosis, anorexia nervosa, delirium, heart failure, ovarian cancer, non-alcoholic fatty liver disease, dyslipidemia, and bacterial pneumonia, but increased risk of Behçet's disease, Graves' disease, kidney stone disease, fracture of radium/ulna, basal cell carcinoma, and overall cataracts. Stratified analyses showed that the inverse association between genetically predisposed 25(OH)D concentrations and multiple sclerosis risk was significant and consistent regardless of the genetic instruments GIs selected. However, the associations with most of the other outcomes were only pronounced when using genetic variants not limited to those in the vitamin D pathway as GIs. The methodological quality of the included MR studies was substantially heterogeneous. Current evidence from linear MR studies strongly supports a causal role of vitamin D in the development of multiple sclerosis. Suggestive support for a number of other health conditions could help prioritize conditions where vitamin D may be beneficial or harmful.

Selective estrogen receptor modulators (SERMs) with vitamin D composite agent can prevent fracture better than SERMs treatment: based on the National Health Claims Database 2017-2019

With the analysis of nationwide health claim data, treatment with the composite agent of SERMs and vitamin D reduces the risk of osteoporotic fracture and hip fracture better compared to SERMs treatment in women with osteoporosis aged ≥ 50 years.

PURPOSE

This study compared the potential of the composite agent of selective estrogen receptor modulators (SERMs) and vitamin D (SERM + VitD) with that of SERMs-only for fracture prevention and mortality reduction in women aged ≥ 50 years.

METHODS

The incidence of osteoporotic fracture (fractures of the vertebrae, hip, wrist, or humerus) and all-cause death after treatment with SERM + VitD and SERMs were characterized using the Korean National Health Insurance Service database 2017-2019. The participants were divided into two groups (SERM + VitD vs SERMs). After exclusion and propensity score matching, 2,885 patients from each group were included in the analysis. Fracture incidence was compared between groups. Kaplan-Meier curves were used to compare mortality. Cox proportional hazards regression analysis was used to compare the risks of fracture occurrence and mortality between the groups.

RESULTS

The incidence rate (138.6/10,000 vs. 192.4/10,000 person-years), and risk of osteoporotic fractures (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.61-0.97; p = 0.024) were lower in the SERM + VitD group than in the SERMs group. Analysis for specific fractures showed a lower hazard of hip fracture in the SERM + VitD group (HR, 0.25; 95% CI, 0.09-0.71; p = 0.009). No difference was observed between the groups regarding mortality.

CONCLUSION

The risk of osteoporotic fractures, especially hip fractures, was lower in the SERM + VitD group than in the SERMs group. Therefore, the composite agent of SERMs and vitamin D can be considered as a viable option for postmenopausal women with a relatively low fracture risk.

Serum 25-hydroxyvitamin D, genetic susceptibility, and the risk of incident type 2 diabetes: A prospective cohort in East China

BACKGROUND

The serum vitamin D level varies widely by population, and studies have linked vitamin D levels with the risk of type 2 diabetes mellitus (T2DM). However, the relationship is inconsistent and the impact of vitamin D on T2DM among East Chinese adults is unclear. The study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and the risk of T2DM and evaluated whether the association is modified by genetic predisposition.

METHODS

In the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) cohort, 1862 participants free of T2DM at baseline were included. A weighted genetic risk score was calculated with 28 variants associated with T2DM. Hierarchical logistic models were used to examine the association of serum 25(OH)D and genetic risk with T2DM.

RESULTS

After a 5-year follow-up, 132 cases of T2DM were documented. We observed no significant association between quartiles of serum 25(OH)D and T2DM risk after multivariable adjustment (χ 2 = 0.571, Pfor trend = 0.426). Compared to those in the lowest quartile of 25(OH)D, the odds ratios (ORs) (95% confidence interval [CI]) for participants with increased quartiles were 1.29 (0.74-2.25), 1.35 (0.77-2.36), and 1.27 (0.72-2.24), respectively. We observed a positive association of glycated hemoglobin (HbA1c) with 25(OH)D at baseline (β = 1.752, P = 0.001) and after follow-up (β = 1.385, P = 0.003), and a negative association of ln conversion homeostasis model assessment (HOMA)-β with 25(OH)D at baseline (β = -0.982, P = 0.021). There was no significant interaction between 25(OH)D and diabetes genetic predisposition on the risk of T2DM (χ 2 = 2.710, Pfor interaction = 0.100). The lowest OR (95% CI) of T2DM was among participants with low genetic risk and the highest quartile of 25(OH)D (0.17 [0.05-0.62]).

CONCLUSION

Serum 25(OH)D may be irrelevant to the risk of incident T2DM among East Chinese adults regardless of genetic predisposition.

Vitamin D Deficiency Is Associated with Advanced Liver Fibrosis and Impaired Fasting Glucose in Alcohol Use Disorder

BACKGROUND

Vitamin D deficiency is a risk factor for liver disease, insulin resistance, and beta cell dysfunction. Individuals with alcohol use disorder (AUD) have many comorbidities, with a heavy burden of liver disease and metabolic complications, including type 2 diabetes mellitus (T2DM).

OBJECTIVE

We aimed to analyze the prevalence and associations of vitamin D deficiency in patients admitted for in-hospital treatment of AUD.

METHODS

A cross-sectional study was conducted in patients consecutively admitted for the treatment of AUD between January 2017 and October 2023. Sociodemographic data, substance use characteristics, and blood parameters were available at admission. Vitamin D status was assessed through the serum concentrations of 25-hydroxyvitamin D [25(OH)D] levels using a direct competitive chemiluminescent immunoassay method. Deficiency of vitamin D was defined as a concentration less than 20 ng/mL; impaired fasting glucose (IFG) was defined by fasting blood glucose >100 mg/dL (5.6 mmol/L), and advanced liver fibrosis by an FIB-4 index >3.25.

RESULTS

Two hundred and forty-three patients were included (75% male) with a mean age of 49 ± 10 years, mean BMI of 26.4 ± 7.3, mean alcohol consumption of 163 ± 81 g/day, and a mean duration of AUD of 18.1 ± 11.2 years. Mean 25(OH)D, fasting blood glucose, AST, ALT, and platelets were 14.4 ± 10.2 ng/mL, 103.4 ± 40.9 mg/dL, 55.1 ± 75.8 U/L, 44.8 ± 76.6 U/L, and 206.3 ± 84.8 × 109/L, respectively. The prevalence of vitamin D deficiency was 80.6%, and 41.1% of patients had levels less than 10 ng/mL. IFG was present in 32.3% of patients, and 20.5% had FIB-4 values >3.25. In the multivariable analysis, IFG (OR, 2.51; 95% CI: 1.02-6.17, p = 0.04) and advanced liver fibrosis (OR, 4.27; 95% CI: 1.21-15.0, p = 0.02) were the only factors associated with vitamin D deficiency.

CONCLUSIONS

Vitamin D deficiency was very prevalent in this series of patients with AUD and was associated with impaired fasting glucose and advanced liver fibrosis.

Loss of the glycosyltransferase Galnt11 affects vitamin D homeostasis and bone composition

O-glycosylation is a conserved posttranslational modification that impacts many aspects of organismal viability and function. Recent studies examining the glycosyltransferase Galnt11 demonstrated that it glycosylates the endocytic receptor megalin in the kidneys, enabling proper binding and reabsorption of ligands, including vitamin D-binding protein (DBP). Galnt11-deficient mice were unable to properly reabsorb DBP from the urine. Vitamin D plays an essential role in mineral homeostasis and its deficiency is associated with bone diseases such as rickets, osteomalacia, and osteoporosis. We therefore set out to examine the effects of the loss of Galnt11 on vitamin D homeostasis and bone composition. We found significantly decreased levels of serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, consistent with decreased reabsorption of DBP. This was accompanied by a significant reduction in blood calcium levels and a physiologic increase in parathyroid hormone (PTH) in Galnt11-deficient mice. Bones in Galnt11-deficient mice were smaller and displayed a decrease in cortical bone accompanied by an increase in trabecular bone and an increase in a marker of bone formation, consistent with PTH-mediated effects on bone. These results support a unified model for the role of Galnt11 in bone and mineral homeostasis, wherein loss of Galnt11 leads to decreased reabsorption of DBP by megalin, resulting in a cascade of disrupted mineral and bone homeostasis including decreased circulating vitamin D and calcium levels, a physiological increase in PTH, an overall loss of cortical bone, and an increase in trabecular bone. Our study elucidates how defects in O-glycosylation can influence vitamin D and mineral homeostasis and the integrity of the skeletal system.

Long-Term Effect of Randomization to Calcium and Vitamin D Supplementation on Health in Older Women : Postintervention Follow-up of a Randomized Clinical Trial

BACKGROUND

Although calcium and vitamin D (CaD) supplementation may affect chronic disease in older women, evidence of long-term effects on health outcomes is limited.

OBJECTIVE

To evaluate long-term health outcomes among postmenopausal women in the Women's Health Initiative CaD trial.

DESIGN

Post hoc analysis of long-term postintervention follow-up of the 7-year randomized intervention trial of CaD. (ClinicalTrials.gov: NCT00000611).

SETTING

A multicenter (n = 40) trial across the United States.

PARTICIPANTS

36 282 postmenopausal women with no history of breast or colorectal cancer.

INTERVENTION

Random 1:1 assignment to 1000 mg of calcium carbonate (400 mg of elemental calcium) with 400 IU of vitamin D3 daily or placebo.

MEASUREMENTS

Incidence of colorectal, invasive breast, and total cancer; disease-specific and all-cause mortality; total cardiovascular disease (CVD); and hip fracture by randomization assignment (through December 2020). Analyses were stratified on personal supplement use.

RESULTS

For women randomly assigned to CaD versus placebo, a 7% reduction in cancer mortality was observed after a median cumulative follow-up of 22.3 years (1817 vs. 1943 deaths; hazard ratio [HR], 0.93 [95% CI, 0.87 to 0.99]), along with a 6% increase in CVD mortality (2621 vs. 2420 deaths; HR, 1.06 [CI, 1.01 to 1.12]). There was no overall effect on other measures, including all-cause mortality (7834 vs. 7748 deaths; HR, 1.00 [CI, 0.97 to 1.03]). Estimates for cancer incidence varied widely when stratified by whether participants reported supplement use before randomization, whereas estimates on mortality did not vary, except for CVD mortality.

LIMITATION

Hip fracture and CVD outcomes were available on only a subset of participants, and effects of calcium versus vitamin D versus joint supplementation could not be disentangled.

CONCLUSION

Calcium and vitamin D supplements seemed to reduce cancer mortality and increase CVD mortality after more than 20 years of follow-up among postmenopausal women, with no effect on all-cause mortality.

PRIMARY FUNDING SOURCE

National Heart, Lung, and Blood Institute of the National Institutes of Health.

Oleanolic acid exerts bone anabolic effects via activation of osteoblastic 25-hydroxyvitamin D 1-alpha hydroxylase

Oleanolic acid (OA) is previously shown to exert bone protective effects in aged animals. However, its role in regulating osteoblastic vitamin D bioactivation, which is one of major causes of age-related bone loss, remains unclear. Our results revealed that treatment of OA significantly increased skeletal CYP27B1 expression and circulating 1,25(OH)2D3 in ovariectomized mice (p <0.01). Moreover, OA upregulated CYP27B1 protein expression and activity, as well as the vitamin D-responsive bone markers alkaline phosphatase (ALP) activity and osteopontin (OPN) protein expression, in human osteoblast-like MG-63 cells (p<0.05). CYP27B1 expression increased along with the osteoblastic differentiation of human bone marrow derived mesenchymal stem cells (hMSCs). CYP27B1 expression and cellular 1,25(OH)2D3 production were further potentiated by OA in cells at mature osteogenic stages. Notably, our study suggested that the osteogenic actions of OA were CYP27B1 dependent. In summary, the bone protective effects of OA were associated with the induction of CYP27B1 activity and expression in bone tissues and osteoblastic lineages. Hence, OA might be a potential approach for management of age-related bone loss.