Optimisation of vitamin D status in global populations.

Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are influenced by many factors including sun exposure, skin pigmentation, covering, season and supplement use. Whilst overt vitamin D deficiency with biochemical consequences presents an increased risk of severe sequelae such as rickets, osteomalacia or cardiomyopathy and usually warrants prompt replacement treatment, the role of vitamin D supplementation in the population presents a different set of considerations. Here the issue is to keep, on average, the population at a level whereby the risk of adverse health outcomes in the population is minimised. This position paper, which complements recently published work from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, addresses key considerations regarding vitamin D assessment and intervention from the population perspective. This position paper, on behalf of the International Osteoporosis Foundation Vitamin D Working Group, summarises the burden and possible amelioration of vitamin D deficiency in global populations. It addresses key issues including screening, supplementation and food fortification.

Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX.

A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX. INTRODUCTION: The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD). METHODS: We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.5 million person-years. The effect of a prior history of fracture on the risk of any clinical fracture, any osteoporotic fracture, major osteoporotic fracture, and hip fracture alone was examined using an extended Poisson model in each cohort. Covariates examined were age, sex, BMD, and duration of follow-up. The results of the different studies were merged by using the weighted ß-coefficients. RESULTS: A previous fracture history, compared with individuals without a prior fracture, was associated with a significantly increased risk of any clinical fracture (hazard ratio, HR = 1.88; 95% CI = 1.72-2.07). The risk ratio was similar for the outcome of osteoporotic fracture (HR = 1.87; 95% CI = 1.69-2.07), major osteoporotic fracture (HR = 1.83; 95% CI = 1.63-2.06), or for hip fracture (HR = 1.82; 95% CI = 1.62-2.06). There was no significant difference in risk ratio between men and women. Subsequent fracture risk was marginally downward adjusted when account was taken of BMD. Low BMD explained a minority of the risk for any clinical fracture (14%), osteoporotic fracture (17%), and for hip fracture (33%). The risk ratio for all fracture outcomes related to prior fracture decreased significantly with adjustment for age and time since baseline examination. CONCLUSION: A previous history of fracture confers an increased risk of fracture of substantial importance beyond that explained by BMD. The effect is similar in men and women. Its quantitation on an international basis permits the more accurate use of this risk factor in case finding strategies.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan.

We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. INTRODUCTION: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide. The aim of this study is to determine whether the current algorithms can be further optimised with respect to current and novel risk factors. METHODS: A computerised literature search was performed in PubMed from inception until May 17, 2019, to identify eligible cohorts for updating the FRAX coefficients. Additionally, we searched the abstracts of conference proceedings of the American Society for Bone and Mineral Research, European Calcified Tissue Society and World Congress of Osteoporosis. Prospective cohort studies with data on baseline clinical risk factors and incident fractures were eligible. RESULTS: Of the 836 records retrieved, 53 were selected for full-text assessment after screening on title and abstract. Twelve cohorts were deemed eligible and of these, 4 novel cohorts were identified. These cohorts, together with 60 previously identified cohorts, will provide the resource for constructing an updated version of FRAX comprising 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures. For each known and candidate risk factor, multivariate hazard functions for hip fracture, major osteoporotic fracture and death will be tested using extended Poisson regression. Sex- and/or ethnicity-specific differences in the weights of the risk factors will be investigated. After meta-analyses of the cohort-specific beta coefficients for each risk factor, models comprising 10-year probability of hip and major osteoporotic fracture, with or without femoral neck bone mineral density, will be computed. CONCLUSIONS: These assembled cohorts and described models will provide the framework for an updated FRAX tool enabling enhanced assessment of fracture risk (PROSPERO (CRD42021227266)).

Effects of Vitamin D with Calcium and Associations of Mean 25-Hydroxyvitamin D Levels with 3-Year Change in Muscle Performance in Healthy Older Adults in the Boston STOP IT Trial.

PURPOSE: The purpose of this analysis was to assess whether (1) daily vitamin D3 plus calcium supplementation vs. placebo or (2) the mean 25-hydroxyvitamin D [25(OH)D] level achieved during a 3-year trial was associated with muscle performance or balance in the Boston STOP IT study. Methods We conducted exploratory analyses in 386 men and women age 65 years and older who participated in the Boston STOP IT trial and had one or more muscle performance or balance assessments at baseline and 3 years. Participants were treated with 700 IU of vitamin D3 plus 500 mg of calcium or with double placebo daily for 3 years. Plasma 25(OH)D was measured at baseline, 6, 12, 18, 24, and 36 months; muscle performance (timed walk, grip strength, and chair-rise) and two balance tests, the one-leg stand and tandem stand, were assessed at baseline and 3 years only. Results Supplementation with vitamin D3 and calcium had no favorable effect on any muscle performance measure. The 3-year mean 25(OH)D levels were 22.7 ± 6.3 (SD) in the placebo and 30.8 ± 7.5 ng/ml in the supplemented groups (p < 0.001). The 3-year mean 25(OH)D level was positively associated with change in one-leg stand time (p = 0.04), but not with the other measures. Conclusion Vitamin D3 and calcium supplementation had no favorable effect on muscle performance or balance in this relatively healthy older population. A higher 3-year mean 25(OH)D level may favor balance, as indicated by longer one-leg stand time, but this observation should be confirmed.

Correction to: Algorithm for the management of patients at low, high and very high risk of osteoporotic fractures.

The article 'Algorithm for the management of patients at low, high and very high risk of osteoporotic fractures',written by J. A. Kanis, was originally published Online First without Open Access. After publication in volume [#], issue [#] and page [#-#], the author decided to opt for Open Choice and to make the article an Open Access publication.

Algorithm for the management of patients at low, high and very high risk of osteoporotic fractures.

Guidance is provided in an international setting on the assessment and specific treatment of postmenopausal women at low, high and very high risk of fragility fractures. INTRODUCTION: The International Osteoporosis Foundation and European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis published guidance for the diagnosis and management of osteoporosis in 2019. This manuscript seeks to apply this in an international setting, taking additional account of further categorisation of increased risk of fracture, which may inform choice of therapeutic approach. METHODS: Clinical perspective and updated literature search. RESULTS: The following areas are reviewed: categorisation of fracture risk and general pharmacological management of osteoporosis. CONCLUSIONS: A platform is provided on which specific guidelines can be developed for national use to characterise fracture risk and direct interventions.

Consensus statement from 2nd International Conference on Controversies in Vitamin D.

The 2nd International Conference on Controversies in Vitamin D was held in Monteriggioni (Siena), Italy, September 11-14, 2018. The aim of this meeting was to address ongoing controversies and timely topics in vitamin D research, to review available data related to these topics and controversies, to promote discussion to help resolve lingering issues and ultimately to suggest a research agenda to clarify areas of uncertainty. Several issues from the first conference, held in 2017, were revisited, such as assays used to determine serum 25-hydroxyvitamin D [25(OH)D] concentration, which remains a critical and controversial issue for defining vitamin D status. Definitions of vitamin D nutritional status (i.e. sufficiency, insufficiency and deficiency) were also revisited. New areas were reviewed, including vitamin D threshold values and how they should be defined in the context of specific diseases, sources of vitamin D and risk factors associated with vitamin D deficiency. Non-skeletal aspects related to vitamin D were also discussed, including the reproductive system, neurology, chronic kidney disease and falls. The therapeutic role of vitamin D and findings from recent clinical trials were also addressed. The topics were considered by 3 focus groups and divided into three main areas: 1) "Laboratory": assays and threshold values to define vitamin D status; 2) "Clinical": sources of vitamin D and risk factors and role of vitamin D in non-skeletal disease and 3) "Therapeutics": controversial issues on observational studies and recent randomized controlled trials. In this report, we present a summary of our findings.

Bone material strength in normoglycemic and hyperglycemic black and white older adults.

This cross-sectional study assessed cortical bone properties via impact microindentation in adults with normoglycemia, prediabetes, and early-stage T2D. Bone material strength index was stable across the glycemia categories in whites but it declined in blacks. Blacks may be more susceptible than whites to impaired cortical bone properties in early diabetes. INTRODUCTION: Individuals with long-standing type 2 diabetes (T2D) have altered cortical bone material properties as determined by impact microindentation. This cross-sectional study was done to determine whether altered cortical bone material properties could be detected in adults with prediabetes or early-stage T2D. METHODS: Men and postmenopausal women aged ≥ 50 years with no diabetes (50 white, 6 black), prediabetes (75 white, 13 black), and T2D of ≤ 5 years duration (24 white and 16 black) had assessments of bone material strength index (BMSi) by impact microindentation, trabecular bone score (TBS), and bone mineral density (BMD) by DXA and the advanced glycation end product, urine pentosidine. RESULTS: The association between glycemia category and BMSi differed by race (interaction p = 0.037). In the whites, BMSi did not differ across the glycemia categories, after adjustment for age, sex, and BMI (no diabetes 76.3 ± 1.6 (SEM), prediabetes 77.2 ± 1.3, T2D 76.2 ± 2.5, ANCOVA p = 0.887). In contrast, in the blacks, BMSi differed (ANCOVA p = 0.020) and was significantly lower in subjects with T2D than in those with prediabetes (p < 0.05) and no diabetes (p < 0.05) (mean ± SEM BMSi in no diabetes 86.0 ± 4.3, prediabetes 91.0 ± 3.2, and T2D 71.6 ± 2.9). Neither TBS nor urine pentosidine differed significantly across the glycemia categories in either whites or blacks. CONCLUSIONS: These findings suggest different associations of glycemia with cortical bone material properties in blacks and whites, with blacks possibly being more susceptible to impaired cortical bone properties than whites in early diabetes. A larger study is needed to verify these observations.

Effects of a simple home exercise program and vitamin D supplementation on health-related quality of life after a hip fracture: a randomized controlled trial.

PURPOSE: To test the effects of vitamin D intervention and a simple home exercise program (HE) on health-related quality of life (HRQL) in the first 12 months after hip fracture. METHODS: HRQL was reported in 173 acute hip fracture patients (mean age 84 years, 79% females, 77% community dwelling) who were enrolled in the 12-month 2 × 2 factorial Zurich Hip Fracture Trial. Pre-fracture HRQL was assessed at baseline (4.2 ± 2.2 days post-surgery) and then again at 6 and 12 months after hip fracture surgery by the EuroQol EQ-5D-3L index value (EQ-5D-3L questionnaire). The effects of vitamin D intervention (2000 vs. 800 IU vitamin D3) and exercise (HE vs. no HE) or of the combined interventions on HRQL were assessed using multivariable-adjusted repeated-measures linear mixed-effects regression models. RESULTS: The EQ-5D-3L index value significantly worsened from 0.71 pre-fracture to 0.57 over 12 months, but the degree of worsening did not differ between individual or combined interventions. However, regarding only the late recovery between 6 and 12 months, the group receiving neither intervention (800 IU/day and no HE) experienced a significant further decline in the EQ-5D-3L index value (adjusted mean change = 0.08 [95% CI 0.009, 0.15], p = 0.03) while all other groups remained stable. CONCLUSION: Hip fractures have a long-lasting negative effect on HRQL up to 12 months after hip fracture. However, HE and/or 2000 IU vitamin D per day may help prevent a further decline in HRQL after the first 6 months following the acute hip fracture event.

Issues of trial selection and subgroup considerations in the recent meta-analysis of Zhao and colleagues on fracture reduction by calcium and vitamin D supplementation in community-dwelling older adults.

Zhao and colleagues are addressing an important question about the efficacy of calcium and vitamin D on fracture risk reduction among community-dwelling adults age 50+. However, we are concerned about four aspects of their approach, which may affect the validity of their conclusions and implications for public health. INTRODUCTION: We discuss the recent meta-analysis by Zhao and colleagues on the primary prevention of fractures of calcium and vitamin D as well as their combination among community-dwelling adults age 50+. METHODS: Zhao and colleagues included 33 trials that recruited a total of 51,145 community-dwelling participants age 50 years and older, including any randomized clinical trial with a placebo or no treatment in the control group. RESULTS: The authors found no significant association of calcium and/or vitamin D with risk of hip fracture compared with placebo or no treatment and concluded that the routine use of calcium, vitamin D, and the combination in community-dwelling older people is not supported by their findings. We discuss four concerns regarding this meta-analysis, including the target population, the selection of trials with regard to blinding and duration of follow-up, and the lack of adjustment for adherence to the interventions and subgroup analysis by bolus versus daily dosing for vitamin D. CONCLUSION: Based on the four concerns raised in this letter and the fact that there will be a manyfold increase in the data on vitamin D supplementation in community-dwelling senior adults from large ongoing trials, we believe that it is too early to recommend the cessation of vitamin D with or without calcium for the prevention of fractures among community-dwelling adults.

Correction to: Global dietary calcium intake among adults: a systematic review.

The original Electronic Supplementary Material file 3 contained an erroneous reference for Mali. A link to the corrected file is provided here.

Increasing alkali supplementation decreases urinary nitrogen excretion when adjusted for same day nitrogen intake.

We examined whether escalating doses of potassium bicarbonate (KHCO3) supplements alter urinary nitrogen excretion expressed as a ratio to same day nitrogen intake (measure of muscle-protein breakdown). The ratio declined significantly from placebo to low to high dose of KHCO3 supplementation in older adults over 3 months, suggesting muscle-sparing. INTRODUCTION: Neutralization of dietary acid load with alkali supplementation (i.e., KHCO3) has been hypothesized to have muscle protein-sparing effects. In controlled feeding studies with fixed nitrogen (N) intake/day, 24-h urinary N excretion is a good marker of muscle breakdown. However, in studies with self-selected diets, changes in 24-h urinary N excretion can be influenced by shifts in N intake. METHODS: We evaluated changes in 24-h total urinary N excretion as a ratio of N excretion to concurrent N intake in 233 older men and women who participated in an 84-day KHCO3 supplementation randomized placebo-controlled trial. RESULTS: After adjustment for relevant cofactors, escalating doses of KHCO3 (1 mmol/kg/day [low] or 1.5 mmol/kg/day [high]) resulted in a progressive decline in urinary N excretion/N intake compared to placebo (overall P for trend = 0.042). The 84-day change in urinary N excretion/N intake in the high-dose KHCO3 group was statistically significantly lower compared to placebo (P = 0.012) but not compared to the low-dose KHCO3 group (P = 0.276). The 84-day change in urinary N excretion/N intake in the low-dose KHCO3 group did not differ significantly from placebo (P = 0.145). CONCLUSIONS: Urinary N excretion expressed as ratio to same day N intake declined steadily with increasing doses of KHCO3 supplementation from low 1 mmol/kg/day to high 1.5 mmol/kg/day, suggesting a nitrogen-sparing effect. Compared to urinary N excretion alone, this ratio could be a more reasonable measure of muscle protein metabolism in large-scale long-term human studies. TRIAL REGISTRATION: Clinicaltrials.gov NCT1475214.

Gender-specific association between dietary acid load and total lean body mass and its dependency on protein intake in seniors.

Diet-related mild metabolic acidosis may play a role in the development of sarcopenia. We investigated the relationship between dietary acid load and total lean body mass in male and female seniors age ≥ 60 years. We found that a more alkaline diet was associated with a higher %TLM only among senior women. INTRODUCTION: The aim of this study was to determine if dietary acid load is associated with total lean body mass in male and female seniors age ≥ 60 years. METHODS: We investigated 243 seniors (mean age 70.3 ± 6.3; 53% women) age ≥ 60 years who participated in the baseline assessment of a clinical trial on vitamin D treatment and rehabilitation after unilateral knee replacement due to severe knee osteoarthritis. The potential renal acid load (PRAL) was assessed based on individual nutrient intakes derived from a food frequency questionnaire. Body composition including percentage of total lean body mass (%TLM) was determined using dual-energy X-ray absorptiometry. Cross-sectional analyses were performed for men and women separately using multivariable regression models controlling for age, physical activity, smoking status, protein intake (g/kg BW per day), energy intake (kcal), and serum 25-hydroxyvitamin D concentration. We included a pre-defined subgroup analysis by protein intake (< 1 g/kg BW day, > 1 g/kg BW day) and by age group (< 70 years, ≥ 70 years). RESULTS: Adjusted %TLM decreased significantly across PRAL quartiles only among women (P trend = 0.004). Moreover, in subgroup analysis, the negative association between the PRAL and %TLM was most pronounced among women with low protein intake (< 1 g/kg BW per day) and age below 70 years (P = 0.002). Among men, there was no association between the PRAL and %TLM. CONCLUSION: The association between dietary acid load and %TLM seems to be gender-specific, with a negative impact on total lean mass only among senior women. Therefore, an alkaline diet may be beneficial for preserving total lean mass in senior women, especially in those with low protein intake.

The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the United States: supplementary presentation.

We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to BMD. The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. Recently an NBHA working Group published a paper in OI with recommendations for expanding the criteria that would constitute an osteoporosis diagnosis in postmenopausal women and in men over age 50 for use in the US - Siris et al., Osteoporosis International 25(%): 1439-1443, 2014. The recommendations have now been endorsed by NOF, ASBMR and a number of professional medical groups and appear in the NOF Clinician's Guide. The new diagnostic criteria continue to include a T-score by DXA of spine or hip that is less than or equal to -2.5, but alternatively also include a hip fracture with or without BMD testing or a vertebral, pelvis, proximal humerus and in some cases a distal forearm fracture in a person with low bone mass, or a FRAX score that meets or exceeds the NOF Guide osteoporosis treatment cut point.

The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the USA.

We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to bone mineral density (BMD). The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. PURPOSE: The purpose of this paper is to estimate the prevalence of osteoporosis in US adults ≥50 years using the NBHA osteoporosis diagnostic criteria. METHODS: Utilizing 2005-2008 data of the National Health and Nutrition Examination Survey (NHANES), we identified participants with osteoporosis with any one of the following: (1) femoral neck or lumbar spine T-score ≤ -2.5; (2) low trauma hip fracture irrespective of BMD or clinical vertebral, proximal humerus, pelvis, or distal forearm fracture with a T-score >-2.5 <-1.0; or (3) FRAX score at the National Osteoporosis Foundation intervention thresholds (≥3% for hip fracture or ≥20% for major osteoporotic fracture). We estimated the prevalence overall and by gender and age. RESULTS: Our sample included 1948 (54.3%) men and 1639 (45.7%) women. Approximately 12% were 80+ years and 21% were from racial/ethnic minority groups. We estimated that 16.0% (0.8) of men and 29.9% (1.0) of women 50+ years have osteoporosis. The prevalence increases with age to 46.3% in men and 77.1% in women 80+ years. The combination of FRAX score and fractures was the largest contributing factor defining osteoporosis in men (70-79, 88.1%; 80+, 80.1%), whereas T-score was the largest contributing factor in women (70-79, 49.2%; 80+, 43.5%). CONCLUSIONS: We found that 16% of men and 29.9% of women 50+ have osteoporosis based on the NBHA diagnostic criteria. Although the expanded definition increases the prevalence compared to BMD alone-based definitions, it may better identify those at elevated fracture risk in order to reduce the burden of fractures in older adults.

Mind the (treatment) gap: a global perspective on current and future strategies for prevention of fragility fractures.

This narrative review considers the key challenges facing healthcare professionals and policymakers responsible for providing care to populations in relation to bone health. These challenges broadly fall into four distinct themes: (1) case finding and management of individuals at high risk of fracture, (2) public awareness of osteoporosis and fragility fractures, (3) reimbursement and health system policy and (4) epidemiology of fracture in the developing world. Findings from cohort studies, randomised controlled trials, systematic reviews and meta-analyses, in addition to current clinical guidelines, position papers and national and international audits, are summarised, with the intention of providing a prioritised approach to delivery of optimal bone health for all. Systematic approaches to case-finding individuals who are at high risk of sustaining fragility fractures are described. These include strategies and models of care intended to improve case finding for individuals who have sustained fragility fractures, those undergoing treatment with medicines which have an adverse effect on bone health and people who have diseases, whereby bone loss and, consequently, fragility fractures are a common comorbidity. Approaches to deliver primary fracture prevention in a clinically effective and cost-effective manner are also explored. Public awareness of osteoporosis is low worldwide. If older people are to be more pro-active in the management of their bone health, that needs to change. Effective disease awareness campaigns have been implemented in some countries but need to be undertaken in many more. A major need exists to improve awareness of the risk that osteoporosis poses to individuals who have initiated treatment, with the intention of improving adherence in the long term. A multisector effort is also required to support patients and their clinicians to have meaningful discussions concerning the risk-benefit ratio of osteoporosis treatment. With regard to prioritisation of fragility fracture prevention in national policy, there is much to be done. In the developing world, robust epidemiological estimates of fracture incidence are required to inform policy development. As the aging of the baby boomer generation is upon us, this review provides a comprehensive analysis of how bone health can be improved worldwide for all.

Global dietary calcium intake among adults: a systematic review.

Low calcium intake may adversely affect bone health in adults. Recognizing the presence of low calcium intake is necessary to develop national strategies to optimize intake. To highlight regions where calcium intake should be improved, we systematically searched for the most representative national dietary calcium intake data in adults from the general population in all countries. We searched 13 electronic databases and requested data from domain experts. Studies were double-screened for eligibility. Data were extracted into a standard form. We developed an interactive global map, categorizing countries based on average calcium intake and summarized differences in intake based on sex, age, and socioeconomic status. Searches yielded 9780 abstracts. Across the 74 countries with data, average national dietary calcium intake ranges from 175 to 1233 mg/day. Many countries in Asia have average dietary calcium intake less than 500 mg/day. Countries in Africa and South America mostly have low calcium intake between about 400 and 700 mg/day. Only Northern European countries have national calcium intake greater than 1000 mg/day. Survey data for three quarters of available countries were not nationally representative. Average calcium intake is generally lower in women than men, but there are no clear patterns across countries regarding relative calcium intake by age, sex, or socioeconomic status. The global calcium map reveals that many countries have low average calcium intake. But recent, nationally representative data are mostly lacking. This review draws attention to regions where measures to increase calcium intake are likely to have skeletal benefits.

The role of calcium supplementation in healthy musculoskeletal ageing : An expert consensus meeting of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the International Foundation for Osteoporosis (IOF).

The place of calcium supplementation, with or without concomitant vitamin D supplementation, has been much debated in terms of both efficacy and safety. There have been numerous trials and meta-analyses of supplementation for fracture reduction, and associations with risk of myocardial infarction have been suggested in recent years. In this report, the product of an expert consensus meeting of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases (ESCEO) and the International Foundation for Osteoporosis (IOF), we review the evidence for the value of calcium supplementation, with or without vitamin D supplementation, for healthy musculoskeletal ageing. We conclude that (1) calcium and vitamin D supplementation leads to a modest reduction in fracture risk, although population-level intervention has not been shown to be an effective public health strategy; (2) supplementation with calcium alone for fracture reduction is not supported by the literature; (3) side effects of calcium supplementation include renal stones and gastrointestinal symptoms; (4) vitamin D supplementation, rather than calcium supplementation, may reduce falls risk; and (5) assertions of increased cardiovascular risk consequent to calcium supplementation are not convincingly supported by current evidence. In conclusion, we recommend, on the basis of the current evidence, that calcium supplementation, with concomitant vitamin D supplementation, is supported for patients at high risk of calcium and vitamin D insufficiency, and in those who are receiving treatment for osteoporosis.

Considerations concerning the definition of sarcopenia.

In this commentary, we describe the sarcopenia spectrum that results in frailty and consider the impact of several components of the frailty definition on its global prevalence. We review proposed operational definitions of sarcopenia and the extent to which they have been shown to predict hard clinical outcomes, such as hip fracture, falls, and mortality. A head-to-head comparison of nine proposed operational definitions of sarcopenia as predictors of falls revealed that the definition involving appendicular lean mass (ALM)/ht2 alone was a significant predictor; the prevalence of sarcopenia by this definition was 11 %. We consider the strengths and limitations of definitions that include functional measurements, such as gait speed and grip strength, along with measures of lean tissue mass. The functional assessments are harder to standardize than the more objective ALM measurements. The prevalence of sarcopenia by definitions that include functional and lean mass measurements tends to be lower than the prevalence by definitions that include lean mass alone. A low prevalence limits opportunity for early identification and application of prevention strategies. For these and other reasons, it seems advantageous to base the operational definition of sarcopenia on ALM/ht2 alone. This commentary addresses the importance of a globally applicable operational definition of sarcopenia and both desirable and undesirable features of such a definition.