Supplemental Vitamin D and Incident Fractures in Midlife and Older Adults.

BACKGROUND: Vitamin D supplements are widely recommended for bone health in the general population, but data on whether they prevent fractures have been inconsistent. METHODS: In an ancillary study of the Vitamin D and Omega-3 Trial (VITAL), we tested whether supplemental vitamin D3 would result in a lower risk of fractures than placebo. VITAL was a two-by-two factorial, randomized, controlled trial that investigated whether supplemental vitamin D3 (2000 IU per day), n-3 fatty acids (1 g per day), or both would prevent cancer and cardiovascular disease in men 50 years of age or older and women 55 years of age or older in the United States. Participants were not recruited on the basis of vitamin D deficiency, low bone mass, or osteoporosis. Incident fractures were reported by participants on annual questionnaires and adjudicated by centralized medical-record review. The primary end points were incident total, nonvertebral, and hip fractures. Proportional-hazards models were used to estimate the treatment effect in intention-to-treat analyses. RESULTS: Among 25,871 participants (50.6% women [13,085 of 25,871] and 20.2% Black [5106 of 25,304]), we confirmed 1991 incident fractures in 1551 participants over a median follow-up of 5.3 years. Supplemental vitamin D3, as compared with placebo, did not have a significant effect on total fractures (which occurred in 769 of 12,927 participants in the vitamin D group and in 782 of 12,944 participants in the placebo group; hazard ratio, 0.98; 95% confidence interval [CI], 0.89 to 1.08; P = 0.70), nonvertebral fractures (hazard ratio, 0.97; 95% CI, 0.87 to 1.07; P = 0.50), or hip fractures (hazard ratio, 1.01; 95% CI, 0.70 to 1.47; P = 0.96). There was no modification of the treatment effect according to baseline characteristics, including age, sex, race or ethnic group, body-mass index, or serum 25-hydroxyvitamin D levels. There were no substantial between-group differences in adverse events as assessed in the parent trial. CONCLUSIONS: Vitamin D3 supplementation did not result in a significantly lower risk of fractures than placebo among generally healthy midlife and older adults who were not selected for vitamin D deficiency, low bone mass, or osteoporosis. (Funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases; VITAL ClinicalTrials.gov number, NCT01704859.).

Randomized trials of estrogen-alone and breast cancer incidence: a meta-analysis.

PURPOSE: In the Women's Health initiative (WHI) randomized clinical trial, conjugated equine estrogen (CEE)-alone significantly reduced breast cancer incidence (P = 0.005). As cohort studies had opposite findings, other randomized clinical trials were identified to conduct a meta-analysis of estrogen-alone influence on breast cancer incidence. METHODS: We conducted literature searches on randomized trials and: estrogen, hormone therapy, and breast cancer, and searches from a prior meta-analysis and reviews. In the meta-analysis, for trials with published relative risks (RR) and 95% confidence intervals (CI), each log-RR was multiplied by weight = 1/V, where V = variance of the log-RR, and V was derived from the corresponding 95% CI. For smaller trials with only breast cancer numbers, the corresponding log-RR = (O - E)/weight, where O is the observed case number in the oestrogen-alone group and E the corresponding expected case number, E = nP. RESULTS: Findings from 10 randomized trials included 14,282 participants and 591 incident breast cancers. In 9 smaller trials, with 1.2% (24 of 2029) vs 2.2% (33 of 1514) randomized to estrogen-alone vs placebo (open label, one trial) (RR 0.65 95% CI 0.38-1.11, P = 0.12). For 5 trials evaluating estradiol formulations, RR = 0.63 95% CI 0.34-1.16, P = 0.15. Combining the 10 trials, 3.6% (262 of 7339) vs 4.7% (329 of 6943) randomized to estrogen-alone vs placebo (overall RR 0.77 95% CI 0.65-0.91, P = 0.002). CONCLUSION: The totality of randomized clinical trial evidence supports a conclusion that estrogen-alone use significantly reduces breast cancer incidence.

Physical function trajectory after wrist or lower arm fracture in postmenopausal women: results from the Women's Health Initiative Study.

Long-term physical functioning trajectories following distal forearm fracture are unknown. We found that women with versus those without distal forearm fracture were more likely to experience a 5-year decline in physical functioning, independent of initial physical functioning level. This association was most evident among women 80 years and older. INTRODUCTION: Physical functioning trajectory following lower arm or wrist fracture is not well understood. PURPOSE: This study is to evaluate physical functioning trajectory before vs. after lower arm or wrist fracture, stratified by age. METHODS: We performed a nested case-control study of prospective data from the Women's Health Initiative Study (n = 2097 cases with lower arm or wrist fracture, 20,970 controls). Self-reported fractures and the physical functioning subscale of the RAND 36-item Short-Form Health Survey were assessed annually. We examined three physical functioning trajectory groups: stable, improving, and declining. RESULTS: Mean (SD) number of physical functioning measurements was 5.2 (1.5) for cases and 5.0 (1.4) for controls. Declining physical functioning was observed among 20.4% of cases and 16.0% of controls. Compared to women without lower arm or wrist fracture, women with lower arm or wrist fracture were 33% more likely to experience declining physical functioning (adjusted odds ratio [aOR] 1.33 95% confidence interval [CI] 1.19-1.49, reference group stable or improving physical functioning trajectory). Associations varied by age: age ≥ 80 years aOR 1.56 (95% CI 1.29-1.88); age 70-79 years aOR 1.29 (95% CI 1.09-1.52); age < 70 years aOR 1.15 (95% CI 0.86-1.53) (pinteraction = 0.06). Associations between lower arm or wrist fracture and odds of declining physical functioning did not vary by baseline physical functioning or physical activity level. CONCLUSIONS: Women with lower arm or wrist fracture, particularly those aged 80 and older, were more likely to experience declines in physical functioning than women without such fractures, independent of baseline physical functioning level.

Menopausal hormone therapy reduces the risk of fracture regardless of falls risk or baseline FRAX probability-results from the Women's Health Initiative hormone therapy trials.

In a combined analysis of 25,389 postmenopausal women aged 50-79 years, enrolled in the two Women's Health Initiative hormone therapy trials, menopausal hormone therapy vs. placebo reduced the risk of fracture regardless of baseline FRAX fracture probability and falls history. INTRODUCTION: The aim of this study was to determine if the anti-fracture efficacy of menopausal hormone therapy (MHT) differed by baseline falls history or fracture risk probability as estimated by FRAX, in a combined analysis of the two Women's Health Initiative (WHI) hormone therapy trials. METHODS: A total of 25,389 postmenopausal women aged 50-79 years were randomized to receive MHT (n = 12,739) or matching placebo (n = 12,650). At baseline, questionnaires were used to collect information on falls history, within the last 12 months, and clinical risk factors. FRAX 10-year probability of major osteoporotic fracture (MOF) was calculated without BMD. Incident clinical fractures were verified using medical records. An extension of Poisson regression was used to investigate the relationship between treatment and fractures in (1) the whole cohort; (2) those with prior falls; and (3) those without prior falls. The effect of baseline FRAX probability on efficacy was investigated in the whole cohort. RESULTS: Over 4.3 ± 2.1 years (mean ± SD), MHT (vs. placebo) significantly reduced the risk of any clinical fracture (hazard ratio [HR] 0.72 [95% CI, 0.65-0.78]), MOF (HR 0.60 [95% CI, 0.53-0.69]), and hip fracture (0.66 [95% CI, 0.45-0.96]). Treatment was effective in reducing the risk of any clinical fracture, MOF, and hip fracture in women regardless of baseline FRAX MOF probability, with no evidence of an interaction between MHT and FRAX (p > 0.30). Similarly, there was no interaction (p > 0.30) between MHT and prior falls. CONCLUSION: In the combined WHI trials, compared to placebo, MHT reduces fracture risk regardless of FRAX probability and falls history in postmenopausal women.

Accounting for Surgical Confounding Factors Affecting Dual-Energy X-ray Absorptiometry in a Large Clinical Trial.

Joint replacements are among the most common orthopedic procedures performed in the U.S. and will continue to increase with the aging population. It is therefore necessary to account for these and other confounding factors, such as breast implants, when performing dual-energy X-ray absorptiometry (DXA) measurements. Whole-body DXA scans were performed in 771 participants (men ≥50 yr and women ≥55 yr) to assess bone mineral density (BMD) and body composition (fat and lean mass). In the DXA scan analyses of participants with internal metal, these affected regions of interest were replaced with measures from the unaffected, contralateral side, consistent with recommendations of the International Society for Clinical Densitometry. T-scores and Z-scores were recalculated using default sex and ethnicity-matched databases. We also explored effects of breast implants on bone density and body composition analyses. Approximately 13.1% of participants had internal metal artifacts at baseline. Replacing metal artifacts with the unaffected, contralateral side decreased the whole-body BMD by an average of 8.1% (SEM 0.84%; n = 67). In participants with unilateral hip (n = 17) and knee replacements (n = 20), BMD was decreased by an average of 14.1% (SEM 1.7%) and 11.2% (SEM 1.1%), respectively. Fat and lean mass were not significantly affected by metal artifacts, as differences between values with and without metal were within 1%. Two participants had bilateral breast implants, and in a separate trial, one participant had a unilateral breast implant. Bone mineral content (BMC) in the region with the breast implant was 5.8 times higher than the contralateral side, and whole-body BMC was increased by 4.7%. Metal artifacts and breast implants can confound DXA whole-body bone but not fat and lean results. It is therefore important in clinical studies to account for these factors to detect physiologically relevant differences in bone measures.

MRI Based Validation of Abdominal Adipose Tissue Measurements From DXA in Postmenopausal Women.

INTRODUCTION: Visceral adipose tissue (VAT) is a hypothesized driver of chronic disease. Dual-energy X-ray absorptiometry (DXA) potentially offers a lower cost and more available alternative compared to gold-standard magnetic resonance imaging (MRI) for quantification of abdominal fat sub-compartments, VAT and subcutaneous adipose tissue (SAT). We sought to validate VAT and SAT area (cm2) from historical DXA scans against MRI. METHODOLOGY: Participants (n = 69) from the Women's Health Initiative (WHI) completed a 3 T MRI scan and a whole body DXA scan (Hologic QDR2000 or QDR4500; 2004-2005). A subset of 43 participants were scanned on both DXA devices. DXA-derived VAT and SAT at the 4th lumbar vertebrae (5 cm wide) were analyzed using APEX software (v4.0, Hologic, Inc., Marlborough, MA). MRI VAT and SAT areas for the corresponding DXA region of interest were quantified using sliceOmatic software (v5.0, Tomovision, Magog, Canada). Pearson correlations between MRI and DXA-derived VAT and SAT were computed, and a Bland-Altman analysis was performed. RESULTS: Participants were primarily non-Hispanic white (86%) with a mean age of 70.51 ± 5.79 years and a mean BMI of 27.33 ± 5.40 kg/m2. Correlations between MRI and DXA measured VAT and SAT were 0.90 and 0.92, respectively (p ≤ 0.001). Bland-Altman plots showed that DXA-VAT slightly overestimated VAT on the QDR4500 (-3.31 cm2); this bias was greater in the smaller subset measured on the older DXA model (QDR2000; -30.71 cm2). The overestimation of DXA-SAT was large (-85.16 to -118.66 cm2), but differences were relatively uniform for the QDR4500. CONCLUSIONS: New software applied to historic Hologic DXA scans provide estimates of VAT and SAT that are well-correlated with criterion MRI among postmenopausal women.

Predicting Fracture Risk in Younger Postmenopausal Women: Comparison of the Garvan and FRAX Risk Calculators in the Women's Health Initiative Study.

BACKGROUND: Guidelines recommend fracture risk assessment in postmenopausal women aged 50-64, but the optimal method is unknown. OBJECTIVES: To compare discrimination and calibration of the Fracture Risk Assessment Tool (FRAX) and Garvan fracture risk calculator for predicting fractures in postmenopausal women aged 50-64 at baseline. DESIGN: Prospective observational study. PARTICIPANTS: Sixty-three thousand seven hundred twenty-three postmenopausal women aged 50-64 years participating in the Women's Health Initiative Observational Study and Clinical Trials. MAIN MEASURES: Incident hip fractures and major osteoporotic fractures (MOF) during 10-year follow-up. Calculated FRAX- and Garvan-predicted hip fracture and MOF fracture probabilities. KEY RESULTS: The observed 10-year hip fracture probability was 0.3% for women aged 50-54 years (n = 14,768), 0.6% for women aged 55-59 years (n = 22,442), and 1.1% for women aged 60-64 years (n = 25,513). At sensitivity thresholds ≥ 80%, specificity of both tools for detecting incident hip fracture during 10 years of follow-up was low: Garvan 30.6% (95% confidence interval [CI] 30.3-31.0%) and FRAX 43.1% (95% CI 42.7-43.5%). At maximal area under the receiver operating characteristic curve (AUC(c), 0.58 for Garvan, 0.65 for FRAX), sensitivity was 16.0% (95% CI 12.7-19.4%) for Garvan and 59.2% (95% CI 54.7-63.7%) for FRAX. At AUC(c) values, sensitivity was lower in African American and Hispanic women than among white women and lower in women aged 50-54 than those 60-64 years old. Observed hip fracture probabilities were similar to FRAX-predicted probabilities but greater than Garvan-predicted probabilities. At AUC(c) values (0.56 for both tools), sensitivity for identifying MOF was also low (range 26.7-46.8%). At AUC(c) values (0.55 for both tools), sensitivity for identifying any clinical fracture ranged from 18.1 to 34.0%. CONCLUSIONS: In postmenopausal women aged 50-64 years, the FRAX and Garvan fracture risk calculator discriminate poorly between women who do and do not experience fracture during 10-year follow-up. There is no useful threshold for either tool.

Vertebral Imaging in the Diagnosis of Osteoporosis: a Clinician's Perspective.

PURPOSE OF REVIEW: Vertebral fractures are the most common osteoporotic fracture and result in functional decline and excess mortality. Dual-energy x-ray absorptiometry (DXA) is the gold standard for the diagnosis of osteoporosis to identify patients at risk for fragility fractures; however, advances in imaging have expanded the role of computed tomography (CT) and magnetic resonance imaging (MRI) in evaluating bone health. RECENT FINDINGS: The utility of CT and MRI in the assessment of bone density is starting to gain traction, particularly when used opportunistically. DXA, conventional radiography, CT, and MRI can all be used to assess for vertebral fractures, and MRI can determine the acuity of fractures. Finally, advances in imaging allow for non-invasive assessment of measures of bone quality, including microarchitecture, bone strength, and bone turnover, to help identify and treat at-risk patients prior to sustaining a vertebral fracture. CT and MRI techniques remain primarily research tools to assess metabolic bone dysfunction, while use of DXA can be clinically expanded beyond measurement of bone density to assess for vertebral fractures and bone architecture to improve fracture risk assessment and guide treatment.

Dehydroepiandrosterone Stimulation of Osteoblastogenesis in Human MSCs Requires IGF-I Signaling.

Dehydroepiandrosterone (DHEA) is an adrenal steroid that circulates in high concentrations in humans in its sulfated form, DHEAS. Clinical and epidemiological studies suggested that low DHEAS levels may be associated with low bone mass. Previously, we and others showed that the effects of DHEA on the skeleton may be conferred partly by their ability to inhibit skeletal catabolic agents, for example, bone resorptive cytokine IL-6. In this study, we tested the hypothesis that the anabolic effects of DHEA on osteoblastogenesis require IGF-I signaling pathways. Using both primary cultures and a cell line of human bone marrow-derived mesenchymal stem cells (hMSCs), we show that DHEA and other steroids stimulate osteoblastogenesis as shown by alkaline phosphatase activity and osteoblast gene induction. The stimulation by DHEA on both IGF-I gene expression and osteoblastogenesis in hMSCs requires IGF-I receptor, PI3K, p38 MAPK, or p42/44 MAPK signaling pathways. This study adds information to indicate that DHEA may be useful for treating bone diseases through its inhibition of skeletal catabolic IL-6 and stimulation of anabolic IGF-I-mediated mechanisms. J. Cell. Biochem. 117: 1769-1774, 2016. © 2015 Wiley Periodicals, Inc.

Effect of age on regulation of human osteoclast differentiation.

Human skeletal aging is characterized as a gradual loss of bone mass due to an excess of bone resorption not balanced by new bone formation. Using human marrow cells, we tested the hypothesis that there is an age-dependent increase in osteoclastogenesis due to intrinsic changes in regulatory factors [macrophage-colony stimulating factor (M-CSF), receptor activator of NF-κB ligand (RANKL), and osteoprotegerin (OPG)] and their receptors [c-fms and RANK]. In bone marrow cells (BMCs), c-fms (r = 0.61, P = 0.006) and RANK expression (r = 0.59, P = 0.008) were increased with age (27-82 years, n = 19). In vitro generation of osteoclasts was increased with age (r = 0.89, P = 0.007). In enriched marrow stromal cells (MSCs), constitutive expression of RANKL was increased with age (r = 0.41, P = 0.049) and expression of OPG was inversely correlated with age (r = -0.43, P = 0.039). Accordingly, there was an age-related increase in RANKL/OPG (r = 0.56, P = 0.005). These data indicate an age-related increase in human osteoclastogenesis that is associated with an intrinsic increase in expression of c-fms and RANK in osteoclast progenitors, and, in the supporting MSCs, an increase in pro-osteoclastogenic RANKL expression and a decrease in anti-osteoclastogenic OPG. These findings support the hypothesis that human marrow cells and their products can contribute to skeletal aging by increasing the generation of bone-resorbing osteoclasts. These findings help to explain underlying molecular mechanisms of progressive bone loss with advancing age in humans.

New Challenges: Use and Interpretation of Radius Bone Mineral Density.

CONTEXT: It is unknown if isolated low bone mineral density (BMD) "osteoporosis" at the radius is associated with increased fracture risk, not only at the wrist but elsewhere and whether it reflects more generalized skeletal fragility. OBJECTIVE: To review the association of radius BMD and fracture risk, the epidemiology of wrist fractures, isolated osteoporosis at the radius and the concordance between radial BMD and femoral neck BMD. METHODS: We completed a narrative literature review on radius BMD and fracture risk and current recommendations for measurement of radial BMD. We updated results of radial BMD and fracture results from the Study of Osteoporotic Fractures over 20 years and examined the concordance of BMD at the distal and proximal radius with femoral neck BMD T -scores. RESULTS: Radius BMD is a robust predictor of all types of fractures including hip and wrist but there is insufficient evidence to suggest that radius BMD predicts wrist fractures better than fractures at other sites. Fractures of the wrist tend to occur in younger, healthier women compared with hip and spine fractures. Nevertheless, wrist fractures are associated with an increased risk of future fractures and represent a missed opportunity for intervention. On a population level, the discordance between radius BMD and femoral neck BMD is small. But women with isolated osteoporosis at the radius had biochemical and microarchitecture deterioration that were similar to women with hip osteoporosis. CONCLUSION: Future research should address the clinical implications of isolated osteoporosis at the radius and whether treatment is warranted.

Vitamin D Supplementation May Prevent or Treat Deficiency After Total Knee Arthroplasty: A Retrospective Cohort Analysis.

BACKGROUND: Vitamin D deficiency is associated with poorer functional outcomes and increased complication rates after total knee arthroplasty (TKA). Yet, there is no longer term study evaluating vitamin D levels and supplementation after TKA. Our study aimed to compare quantitative vitamin D levels and supplementation regimens after TKA stratified by patient sex and race. METHODS: A retrospective cohort study of primary TKA patients at a single hospital from 2015 to 2022 was conducted. We analyzed vitamin D preoperatively and postoperatively up to 2 years. Vitamin D deficiency was defined as <30 ng/mL. A subgroup analysis was conducted in patients with vitamin D <21 ng/mL. Supplementation categories included none, low (<1,001 IU), medium (1,001 to 5,000 IU), and high (>5,000 IU). RESULTS: A total of 400 (66.0% female) patients who underwent 430 primary TKA procedures were included, and 65.3% received supplementation. Patients who were vitamin D sufficient preoperatively demonstrated higher vitamin D levels and ability to maintain sufficiency postoperatively using low-dose supplementation compared with no supplementation (P = 0.004). Those who were vitamin D deficient preoperatively demonstrated higher vitamin D levels postoperatively using medium to high doses (P = 0.02). For patients who became deficient postoperatively, supplementation was associated with achieving repletion at an average of 10.2 months (P < 0.001). Black patients demonstrated 2.8 times higher odds of having a vitamin D level less than 30 ng/mL (P = 0.03). CONCLUSION: Our study demonstrated that low-dose vitamin D supplementation (<1,001 IU) was beneficial for vitamin D-sufficient TKA patients to achieve higher levels and maintain vitamin D sufficiency. Vitamin D-deficient TKA patients benefitted from medium-to-high dose supplementation (1,001 to 5,000+), but only 33.7% achieved vitamin D repletion. This work highlights the need to continue vitamin D surveillance postoperatively and the need to continue vitamin D repletion.

Effects of Supplemental Vitamin D3, Omega-3 Fatty Acids on Physical Performance Measures in VITamin D and OmegA-3 TriaL.

CONTEXT: Declining muscle strength and performance in older adults are associated with falls, fractures, and premature death. OBJECTIVE: To determine whether supplementation with vitamin D3 or omega-3 fatty acids vs. placebo for 2 years improves physical performance measures. DESIGN: VITamin D and OmegA-3 TriaL (VITAL) was a double-blinded, placebo-controlled randomized trial of supplemental vitamin D3 and/or omega-3 fatty acids vs. placebo in the prevention of cancer and cardiovascular disease in 25,871 U.S. adults. This ancillary study was completed in a New England sub-cohort that had in-person evaluations at baseline and 2-year follow-up. SETTING: Center for Clinical Investigations in Boston. PARTICIPANTS: 1,054 participants (men ≥50 and women ≥55 years). INTERVENTIONS: 2x2 factorial design of supplemental vitamin D3 (cholecalciferol, 2000 IU/day) and/or marine omega-3 fatty acids (1 g/day). MAIN OUTCOME MEASURES: 2-year changes in physical performance measures of grip strength, walking speed, standing balance, repeated chair stands, and Timed-up and Go (TUG). RESULTS: At 2 years, all randomized groups showed worsening walking speeds and TUG. There were no differences in changes in grip strength, walking speeds, Short Physical Performance Battery (composite of walking speed, balance, and chair stands), and TUG between the vitamin D3-treated and the placebo-treated groups and between the omega-3-treated and the placebo-treated groups. Effects overall did not vary by sex, age, body mass index, or baseline measures of total or free 25-hydroxyvitamin D (25[OH]D) or plasma n-3 index; TUG slightly worsened with vitamin D supplementation, compared to placebo, in participants with baseline total 25(OH)D levels above the median (p=0.01, p for interaction=0.04). CONCLUSIONS: Neither supplemental vitamin D3 nor marine omega-3 fatty acids for 2 years improved physical performance in this generally healthy adult population.

Dietary Intervention Favorably Influences Physical Functioning: The Women's Health Initiative Randomized Dietary Modification Trial.

BACKGROUND: In the Women's Health Initiative Dietary Modification randomized trial, the dietary intervention reduced breast cancer mortality by 21% (P = .02) and increased physical activity as well. OBJECTIVE: Therefore, the aim was to examine whether or not these lifestyle changes attenuated age-related physical functioning decline. DESIGN: In a randomized trial, the influence of 8 years of a low-fat dietary pattern intervention was examined through 20 years of cumulative follow-up. PARTICIPANTS AND SETTING: From 1993 to 1998, 48,835 postmenopausal women, ages 50 to 79 years with no prior breast cancer and negative baseline mammogram were randomized at 40 US clinical centers to dietary intervention or usual diet comparison groups (40 out of 60). The intervention significantly reduced fat intake and increased vegetable, fruit, and grain intake. MAIN OUTCOME MEASURES: In post hoc analyses, physical functioning, assessed using the RAND 36-Item Short Form Health Survey, evaluated quality or limitations of 10 hierarchical physical activities. Longitudinal physical functioning, reported against a disability threshold (when assistance in daily activities is required) was the primary study outcome. STATISTICAL ANALYSES PERFORMED: Semiparametric linear mixed effect models were used to contrast physical functioning trajectories by randomization groups. RESULTS: Physical functioning score, assessed 495,317 times with 11.0 (median) assessments per participant, was significantly higher in the intervention vs comparison groups through 12 years of cumulative follow-up (P = .001), representing a reduction in age-related functional decline. The intervention effect subsequently attenuated and did not delay time to the disability threshold. Among women in the dietary intervention vs comparison groups, aged 50 to 59 years, who were physically inactive at entry, a persistent, statistically significant, favorable influence on physical functioning with associated delay in crossing the disability threshold by approximately a year was seen (P value for interaction = .007). CONCLUSIONS: In the Women's Health Initiative Dietary Modification randomized trial, a dietary intervention that significantly reduced breast cancer mortality also significantly reduced age-related functional decline through 12 years, which was attenuated with longer follow-up.

Health Effects of Vitamin D Supplementation: Lessons Learned From Randomized Controlled Trials and Mendelian Randomization Studies.

Vitamin D plays an important role in calcium homeostasis and many cellular processes. Although vitamin D supplements are widely recommended for community-dwelling adults, definitive data on whether these supplements benefit clinically important skeletal and extraskeletal outcomes have been conflicting. Although observational studies on effects of vitamin D on musculoskeletal and extraskeletal outcomes may be confounded by reverse causation, randomized controlled studies (RCTs) and Mendelian randomization (MR) studies can help to elucidate causation. In this review, we summarize the recent findings from large RCTs and/or MR studies of vitamin D on bone health and risk of fractures, falls, cancer, and cardiovascular disease, disorders of the immune system, multiple sclerosis, and mortality in community-dwelling adults. The primary analyses indicate that vitamin D supplementation does not decrease bone loss, fractures, falls, cancer incidence, hypertension, or cardiovascular risk in generally healthy populations. Large RCTs and meta-analyses suggest an effect of supplemental vitamin D on cancer mortality. The existence of extraskeletal benefits of vitamin D supplementations are best documented for the immune system especially in people with poor vitamin D status, autoimmune diseases, and multiple sclerosis. Accumulating evidence indicates that vitamin D may reduce all-cause mortality. These findings, in mostly vitamin D-replete populations, do not apply to older adults in residential communities or adults with vitamin D deficiency or osteoporosis. The focus of vitamin D supplementation should shift from widespread use in generally healthy populations to targeted vitamin D supplementation in select individuals, good nutritional approaches, and elimination of vitamin D deficiency globally. © 2023 American Society for Bone and Mineral Research (ASBMR).

The Effects of Vitamin D Supplementation on Musculoskeletal Health: The VITAL and DO-Health Trials.

Previous clinical trials and systematic reviews on the effects of supplemental vitamin D on musculoskeletal outcomes are conflicting. In this paper, we review the literature and summarize the effects of a high daily dose of 2 000 IU vitamin D on musculoskeletal outcomes in generally healthy adults, in men (≥50 years) and women (≥55 years) in the 5.3-year US VITamin D and OmegA-3 TriaL (VITAL) trial (n = 25 871) and women and men (≥70 years) in the 3-year European DO-HEALTH trial (n = 2 157). These studies found no benefit of 2 000 IU/d of supplemental vitamin D on nonvertebral fractures, falls, functional decline, or frailty. In VITAL, supplementation with 2 000 IU/d of vitamin D did not reduce the risk of total or hip fractures. In a subcohort of VITAL, supplemental vitamin D did not improve bone density or structure (n = 771) or physical performance measures (n = 1 054). In DO-HEALTH, which investigated additive benefits of vitamin D with omega-3 and a simple home exercise program, the 3 treatments combined showed a significant 39% decreased odds of becoming prefrail compared to the control. The mean baseline 25(OH)D levels were 30.7 ± 10 ng/mL in VITAL and 22.4 ± 8.0 ng/mL in DO-HEALTH and increased to 41.2 ng/mL and 37.6 ng/mL in the vitamin D treatment groups, respectively. In generally healthy and vitamin D-replete older adults not preselected for vitamin D deficiency or low bone mass or osteoporosis, 2 000 IU/d of vitamin D had no musculoskeletal health benefits. These findings may not apply to individuals with very low 25(OH)D levels, gastrointestinal disorders causing malabsorption, or those with osteoporosis.

Association of Body Weight With Response to Vitamin D Supplementation and Metabolism.

Importance: In the Vitamin D and Omega-3 Trial (VITAL), the effects of randomized vitamin D supplementation (cholecalciferol), 2000 IU/d, reduced the risk of several health outcomes among participants with normal, but not elevated, body weights. It was unclear whether weight had any association with the outcomes of the supplementation. Objective: To investigate whether baseline body mass index (BMI) modifies vitamin D metabolism and response to supplementation. Design, Setting, and Participants: VITAL is a completed randomized, double-blind, placebo-controlled trial for the primary prevention of cancer and cardiovascular disease. In the present cohort study, an analysis was conducted in a subset of VITAL participants who provided a blood sample at baseline and a subset with a repeated sample at 2 years' follow-up. VITAL was conducted from July 1, 2010, to November 10, 2018; data analysis for the present study was conducted from August 1, 2021, to November 9, 2021. Interventions: Treatment outcomes of vitamin D, 2000 IU/d, supplementation vs placebo associated with clinical and novel vitamin D-related biomarkers by BMI category adjusted for other factors associated with vitamin D status. Main Outcomes and Measures: Multivariable-adjusted means (SE) or 95% CIs of vitamin D-related serum biomarkers at baseline and follow-up: total 25-hydroxyvitamin D (25-OHD), 25-OHD3, free vitamin D (FVD), bioavailable vitamin D (BioD), vitamin D-binding protein (VDBP), albumin, parathyroid hormone (PTH), and calcium, and log-transformed as needed. Results: A total of 16 515 participants (mean [SD] age, 67.7 [7.0] years; 8371 women [50.7%]; 12420 non-Hispanic White [76.9%]) were analyzed at baseline, including 2742 with a follow-up blood sample. Before randomization, serum total 25-OHD levels were incrementally lower at higher BMI categories (adjusted mean [SE]: underweight, 32.3 [0.7] ng/mL; normal weight, 32.3 [0.1] ng/mL; overweight, 30.5 [0.1] ng/mL; obesity class I, 29.0 [0.2] ng/mL; and obesity class II, 28.0 [0.2] ng/mL; P < .001 for linear trend). Similarly, baseline 25-OHD3, FVD, BioD, VDBP, albumin, and calcium levels were lower with higher BMI, while PTH level was higher (all P < .001 for linear trend). Compared with placebo, randomization to vitamin D supplementation was associated with an increase in total 25-OHD, 25-OHD3, FVD, and BioD levels compared with placebo at 2 years' follow-up, but increases were significantly lower at higher BMI categories (all treatment effect interactions P < .001). Supplementation did not substantially change VDBP, albumin, PTH, or calcium levels. Conclusions and Relevance: In this randomized cohort study, vitamin D supplementation increased serum vitamin D-related biomarkers, with a blunted response observed for participants with overweight or obesity at baseline. These longitudinal findings suggest that BMI may be associated with modified response to vitamin D supplementation and may in part explain the observed diminished outcomes of supplementation for various health outcomes among individuals with higher BMI.

Rationale and design of an ancillary study evaluating the effects of the cocoa flavanol and/or multivitamin interventions on falls and physical performance outcomes in the COcoa Supplement and Multivitamin Outcomes Study (COSMOS).

BACKGROUND: Falls and decreased physical function increase markedly with age and result in injury, hospitalization, and premature death. Emerging studies show potential benefits of supplemental cocoa extract on physical performance, including grip strength and walking speed in older adults. However, there are no large, long-term randomized controlled trials of effects of supplemental cocoa extract on falls, muscle performance, and/or fall-related injuries. METHODS: The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a double-blind, placebo-controlled, 2 × 2 factorial trial investigating effects of supplementation with cocoa extract (500 mg/d, including 80 mg (-)-epicatechin) and/or a multivitamin on prevention of cardiovascular disease and cancer in 21,442 women (≥65 years) and men (≥60 years). COSMOS: Effects on Falls and Physical Performance is an ancillary study to COSMOS that will clarify effects of cocoa extract and/or multivitamin supplementation on falls, physical performance, and incident fracture outcomes in older adults. Injurious fall(s) resulting in healthcare utilization and recurrent falls were regularly assessed by follow-up questionnaires in the overall cohort. Incident fractures were also assessed by annual questionnaires. Circumstances surrounding falls and any fall-related injuries will be confirmed by medical record review. Effects of the interventions on 2-year changes in physical performance measures (grip strength, walking speed, and the Short Physical Performance Battery) will be tested in a clinic sub-cohort (n = 603). CONCLUSION: Results from this ancillary study will determine whether supplemental cocoa extract slows age-related declines in physical performance and decrease injurious and recurrent falls and fall-related injuries and fractures that are major public health problems in older adults.