Serum 25-hydroxyvitamin D level and risk of falls in Japanese community-dwelling elderly women: a 1-year follow-up study

Vitamin D, C-Reactive Protein, and Increased Fall Risk: A Genetic Epidemiological Study

Background: Falls are a major public health concern. Daily vitamin D supplementation is a proposed fall prevention strategy; however, safety concerns have arisen from some clinical trials showing increased fall risk when using higher vitamin D dosing methods. The relationship between vitamin D and falls may be influenced by factors, such as inflammation, which can alter the balance of essential nutrients like vitamin D and retinol, potentially affecting motor function. We use a genetic epidemiological approach to explore the association of inflammation, vitamin D, and fall risk. Methods: We included 307,082 UK Biobank participants and conducted observational and Mendelian randomization (MR) analyses to investigate associations between 25-hydroxyvitamin D [25(OH)D] and fall risk, with analyses including restriction to participants who had fallen and had inflammation as defined by CRP ≥ 5 mg/L. Results: In the observational analysis, CRP was associated with a higher (per 5 mg/L CRP increase OR = 1.06, 95% CI 1.05-1.07) and 25(OH)D with a lower odds of falls. The association between 25(OH)D concentrations and fall risk was non-linear (p < 0.001), reflecting a plateauing of the association at higher concentrations. There was an interaction between 25(OH)D and CRP on their association with the odds of falls (p = 0.009). In participants with CRP ≥ 5 mg/L, the association was U-shaped, and the fall risk was elevated for both 25(OH)D < 25 nmol/L and ≥ 100 nmol/L (p < 0.004). The association between high 25(OH)D and falls was most pronounced for participants with CRP ≥ 20 mg/L (≥ 100 nmol/L vs. 50-74.99 nmol/L: OR = 2.40, 95% CI, 1.50-3.86). Genetically predicted higher 25(OH)D was not associated with fall risk in the overall population, but a suggestive association with fall risk was seen in participants who had fallen and had CRP > 20 mg/L (926 cases; OR = 1.20, 95% CI, 1.00-1.44). Conclusions: Our study suggests that inflammation might modify the vitamin D and fall risk relationship. Both low and high 25(OH)D levels are associated with more falls in individuals with chronic inflammation, with supporting evidence seen in both observational and MR analyses. This may provide insight into the increased fall risk following high-dose vitamin D supplementation in clinical trials, warranting further research.

Vitamin D and/or calcium to prevent fractures and falls: protocol for a systematic review and meta-analysis

BACKGROUND

Previous systematic reviews on fracture and fall prevention have generally shown no efficacy with calcium or vitamin D alone and conflicting findings with that of vitamin D combined with calcium. Despite these findings, increases in vitamin D and calcium prescriptions have been reported in many countries, as many clinicians, guidelines and regulatory agencies still largely recommend universal supplementation to adults.

METHODS AND ANALYSIS

We will conduct a systematic review of randomised controlled trials on the efficacy of vitamin D and/or calcium in fracture and fall prevention. A systematic search will be performed in Medline, Embase, CENTRAL, International Clinical Trials Registry Platform and Clinicaltrials.gov (1 January 2024). We will also hand search abstracts published in relevant congress and journals (2021-2023) and the reference lists of included trials. We will consider any trial involving the pharmacological administration of calcium alone, vitamin D alone or vitamin D combined with calcium against placebo or no treatment in adults. The primary outcome will be the number of participants with fractures at any site. The secondary outcomes will be the number of participants with hip fractures, non-vertebral fractures, vertebral fractures and falls, and the rate of falls. Two reviewers will independently screen and include the trials, extract the data and assess the risk of bias using the second version of the Cochrane risk-of-bias tool. We plan to pool outcomes to conduct random-effects meta-analyses and to appraise the certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE). Many prespecified subgroup and sensitivity analyses will be performed to explore the potential heterogeneity and to test the robustness of our findings.

ETHICS AND DISSEMINATION

This systematic review does not require research ethics approval. The results will be disseminated in peer-reviewed journals and help inform clinicians, guidelines and regulatory agencies.

PROSPERO REGISTRATION NUMBER

CRD42023483915.

Vitamin D and Sarcopenia in the Senior People: A Review of Mechanisms and Comprehensive Prevention and Treatment Strategies

This article reviews the mechanisms and prevention strategies associated with vitamin D and sarcopenia in older adults. As a geriatric syndrome, sarcopenia is defined by a notable decline in skeletal muscle mass and strength, which increases the risk of adverse health outcomes such as falls and fractures. Vitamin D, an essential fat-soluble vitamin, is pivotal in skeletal muscle health. It affects muscle function through various mechanisms, including regulating calcium and phosphorus metabolism, promoting muscle protein synthesis, and modulation of muscle cell proliferation and differentiation. A deficiency in vitamin D has been identified as a significant risk factor for the development of sarcopenia in older adults. Many studies have demonstrated that low serum vitamin D levels are significantly associated with an increased risk of sarcopenia. While there is inconsistency in the findings, most studies support the importance of vitamin D in maintaining skeletal muscle health. Vitamin D influences the onset and progression of sarcopenia through various pathways, including the promotion of muscle protein synthesis, the regulation of mitochondrial function, and the modulation of immune and inflammatory responses. Regarding the prevention and treatment of sarcopenia, a combination of nutritional, exercise, and pharmacological interventions is recommended. Further research should be conducted to elucidate the molecular mechanism of vitamin D in sarcopenia, to study genes related to sarcopenia, to perform large-scale clinical trials, to investigate special populations, and to examine the combined application of vitamin D with other nutrients or drugs. A comprehensive investigation of the interconnection between vitamin D and sarcopenia will furnish a novel scientific foundation and productive strategies for preventing and treating sarcopenia. This, in turn, will enhance the senior people's quality of life and health.

Low plasma 25-hydroxyvitamin D levels are not associated with a high risk of recurrent falls in community-dwelling Japanese adults: the Murakami cohort study

Reports on the association between vitamin D levels and fall risk have been mixed, and long-term follow-up studies are lacking. This 5-year cohort study of 5,343 community-dwelling Japanese people aged 40-74 years found that low vitamin D levels are not associated with a high risk of recurrent falls.

PURPOSE

Findings of cohort studies on the association between plasma 25-hydoxyvitamin D (25[OH]D) levels and fall risk have been mixed, and long-term follow-up studies are lacking. The present study investigated whether low plasma 25(OH)D levels are longitudinally associated with a high risk of recurrent falls in adults.

METHODS

This 5-year cohort study included 5,343 community-dwelling Japanese people aged 40-74 years. Baseline blood collection and a questionnaire survey were conducted in 2011-2013. Plasma 25(OH)D levels were determined and divided into quintiles after stratification by season, sex, and age group. Information on recurrent falls occurring in the year before the survey 5 years later was obtained, and participants with two or more falls were considered to have experienced recurrent falls. Covariates were sex, age, marital status, education, occupation, BMI, total physical activity levels, calcium intake, vitamin K intake, smoking, drinking, and disease history.

RESULTS

Mean age and 25(OH)D levels were 60.9 years and 50.9 nmol/L, respectively. In the follow-up survey, 209 recurrent falls were reported. Plasma 25(OH)D levels were not significantly associated with the occurrence of recurrent falls in men, women, or men/women-combined (adjusted P for trend = 0.1198, 0.8383, and 0.2355, respectively). In men and men/women-combined, adjusted ORs for recurrent falls in the lowest quintile were significantly lower (adjusted OR = 0.42 and 0.59, respectively) than the middle quintile (reference).

CONCLUSION

Low plasma 25(OH)D levels are not associated with a high risk of recurrent falls in middle-aged and older people. Further longitudinal studies will be needed to confirm our findings in other populations.

Fat as a Friend or Foe of the Bone

PURPOSE OF REVIEW

The objective of this review is to summarize the literature on the prevalence and diagnosis of obesity and its metabolic profile, including bone metabolism, focusing on the main inflammatory and turnover bone mediators that better characterize metabolically healthy obesity phenotype, and to summarize the therapeutic interventions for obesity with their effects on bone health.

RECENT FINDINGS

Osteoporosis and fracture risk not only increase with age and menopause but also with metabolic diseases, such as diabetes mellitus. Thus, patients with high BMI may have a higher bone fragility and fracture risk. However, some obese individuals with healthy metabolic profiles seem to be less at risk of bone fracture. Obesity has become an alarming disease with growing prevalence and multiple metabolic comorbidities, resulting in a significant burden on healthcare and increased mortality. The imbalance between increased food ingestion and decreased energy expenditure leads to pathological adipose tissue distribution and function, with increased secretion of proinflammatory markers and harmful consequences for body tissues, including bone tissue. However, some obese individuals seem to have a healthy metabolic profile and may not develop cardiometabolic disease during their lives. This healthy metabolic profile also benefits bone turnover and is associated with lower fracture risk.

Lack of vitamin D signalling shifts skeletal muscles towards oxidative metabolism

BACKGROUND

Mice lacking vitamin D receptor (VDR) exhibit a glycogen storage disorder, disrupting carbohydrate utilization in muscle. Here, we asked if the defective carbohydrate metabolism alters the fat utilization by the skeletal muscles of vdr-/- mice.

METHODS

To check the effect of high-fat-containing diets on muscle mass and metabolism of vdr-/- mice, we subjected them to two different milk fat-based diets (milk fat diet with 60% of energy from milk fat and milk-based diet [MBD] with 37% of energy from milk fat) and lard-based high-fat diet (HFD) containing 60% of energy from lard fat. Skeletal muscles and pancreas from these mice were analysed using RNA sequencing, quantitative reverse transcription polymerase chain reaction and western blot to understand the changes in signalling and metabolic pathways. Microscopic analyses of cryosections stained with haematoxylin and eosin, BODIPY, succinate dehydrogenase and periodic acid-Schiff reagent were performed to understand changes in morphology and metabolism of muscle fibres and pancreatic islets.

RESULTS

Transcriptomic analyses showed that the skeletal muscles of vdr-/- mice exhibit upregulation of the fatty acid oxidation pathways, suggesting a shift towards increased lipid utilization even in a carbohydrate-enriched regular chow diet (chow). Two different milk fat-enriched diets restored body weight (12.01 ± 0.33 g in chow vs. 17.99 ± 0.62 g in MBD) and muscle weights (38.58 ± 3.84 mg in chow vs. 110.72 ± 1.96 mg in MBD for gastrocnemius [GAS]) of vdr-/- mice. Muscle ATP levels (0.56 ± 0.18 μmol in chow vs. 1.48 ± 0.08 μmol in MBD) and protein synthesis (0.25 ± 0.04 A.U. in chow vs. 2.02 ± 0.06 A.U. in MBD) were upregulated by MBD. However, despite increasing muscle energy levels, HFD failed to restore the muscle mass and cross-sectional area to that of wild-type (WT) mice (104.95 ± 2.6 mg for WT mice on chow vs. 77.26 ± 1.7 mg for vdr-/- mice on HFD for GAS). Moreover, HFD disrupted glucose homeostasis in vdr-/- mice, while MBD restored it. We further analysed insulin response and pancreatic insulin levels of these mice to show that HFD led to reduced insulin levels in pancreatic beta cells of vdr-/- mice (mean intensity of 1.5 × 10-8 for WT mice on chow vs. 4.3 × 10-9 for vdr-/- mice on HFD). At the same time, MBD restored glucose-stimulated pancreatic insulin response (mean intensity of 9.2 × 10-9 ).

CONCLUSIONS

Skeletal muscles of vdr-/- mice are predisposed to utilize fatty acids as their primary energy source to circumvent their defective carbohydrate utilization. Thus, HFDs could restore energy levels in the skeletal muscles of vdr-/- mice. This study reveals that when mice are subjected to a lard-based HFD, VDR signalling is essential for maintaining insulin levels in pancreatic islets. Our data show a critical role of VDR in muscle metabolic flexibility and pancreatic insulin response.

High serum 25-hydroxyvitamin D levels are associated with greater lean tissue mass and skeletal muscle mass:a cross-sectional study on young healthy Japanese women

Studies have shown that low serum 25(OH)D levels in young women may affect not only their own health but also the health of next generation through pregnancy and childbirth. The aim of this study is to assess the serum 25(OH)D levels in young Japanese women and to determine the factors influencing the changes in their serum 25(OH)D levels. Herein, 83 healthy young Japanese women were included. Early morning fasting blood samples, habitual food intake survey, eating habits survey, and anthropometric measurements were used to analyze the relationship between the serum 25(OH)D levels and nutrient intake, intake of food groups, dietary habits, and body composition. The findings revealed that about 50% of the study participants had an adequate intake (AI) of vitamin D (8.5 µg), whereas about 88% of the study participants were vitamin D deficient and about 12% were insufficient in serum 25(OH) levels. No significant association was observed between the serum 25(OH)D levels and nutrient intake or intake of food groups. Furthermore, higher serum 25(OH)D levels were associated with higher percentages of muscle and lean tissue, indicating that regulating the serum 25(OH)D levels helps maintain muscle mass and lowers the risk of sarcopenia and locomotive syndrome. J. Med. Invest. 71 : 260-266, August, 2024.

Association between Masticatory Performance, Nutritional Intake, and Frailty in Japanese Older Adults

The older adult population in Japan is expected to increase. Therefore, long-term care and frailty prevention are important. However, the relationship between masticatory performance, nutritional intake, and frailty remains unclear. This cross-sectional study aimed to examine energy, protein, and vitamin D intake and its association with frailty and masticatory performance in older adults. Patients between January 2022 and January 2023 were recruited and divided into robust and frail groups. Masticatory performance, nutrition, frailty, and other data, such as age and sex, were evaluated through onsite measurements and a questionnaire. Logistic regression analysis was conducted with frailty as a dependent variable and masticatory performance as an independent variable, adjusting for age, sex, skeletal muscle mass, living alone, energy intake, protein-energy ratio, and vitamin D intake. No significant differences were observed between the groups regarding age or sex. The robust group showed significantly better results for protein-energy ratio, vitamin D intake, and subjective and objective masticatory performance than the frail group. Logistic regression analysis revealed a significant correlation between skeletal muscle mass, protein-energy ratio, and objective masticatory performance with frailty. Masticatory performance was associated with frailty, independent of the intake of nutrients such as energy, protein, and vitamin D.

Serum levels of vitamin D and periodontal inflammation in community-dwelling older Japanese adults: The Otassha Study

AIM

To evaluate the association between vitamin D status and periodontal inflammation as determined by the periodontal inflamed surface area (PISA) in community-dwelling older adults.

MATERIALS AND METHODS

This cross-sectional study included 467 Japanese adults (mean age = 73.1 years) who underwent full-mouth periodontal examinations and measurements of serum levels of 25-hydroxyvitamin D (25(OH)D). We used linear regression and restricted cubic spline models to analyse the association between exposure (serum 25(OH)D) and outcome (PISA).

RESULTS

The linear regression model showed that, after adjusting for potential confounders, participants in the lowest quartile of serum 25(OH)D had 41.0 mm2 more PISA (95% confidence interval [CI]: 4.6-77.5) than the reference group (the highest quartile of serum 25(OH)D). The spline model showed that the association between serum 25(OH)D and PISA was non-linear and restricted to the low 25(OH)D range. PISA initially sharply decreased as serum 25(OH)D increased, and then the decreasing trend slowed and plateaued. The inflection point with the minimum PISA value was a serum 25(OH)D level of 27.1 ng/mL, above which there was no decreasing trend in PISA with increasing serum 25(OH)D levels.

CONCLUSIONS

Low vitamin D status had an L-shaped association with periodontal inflammation in this cohort of Japanese adults.

A prospective analysis of concentration of 25-OHD between northern and southern district in Japan in year-round study

Although osteoporotic patients have already been recognized as having a low-volume vitamin D status, the concentration of active vitamin D precursor has not been studied in detail. This trial aimed to clarify the concentration of 25-hydroxyvitamin D (25-OHD), which is a natural type of vitamin D and compare between 2 separate areas in Japan. To compare and clarify the concentration of 25-OHD between 2 separate areas, Japanese patients who were diagnosed as having osteoporosis based on bone mineral density were studied. We analyzed 2 different hospitals' patients whose residence is separated into a northern district (Akita city: north latitude 39" 43') and a southern district (Shizuoka city: north latitude 34" 58'). Both of them have completely different daylight hours. Three-hundred sixty eight patients (174 in Akita, 194 in Shizuoka) were enrolled in this trial to compare the differences of concentration of 25-OHD by Welch's t t-test. There were significant differences in the concentration of 25-OHD and age between them. Akita patients were significantly higher than that of Shizuoka patients despite Shizuoka having much daylight hours of Akita. In conclusion, there might be no relationship between the concentration of 25 OHD and exposure to sunlight.

The Relationship of Falls With Achieved 25-Hydroxyvitamin D Levels From Vitamin D Supplementation: The STURDY Trial

Context

The Study to Understand Fall Reduction and Vitamin D in You (STURDY), a randomized trial enrolling older adults with low 25-hydroxyvitamin D [25(OH)D], demonstrated vitamin D supplementation ≥ 1000 IU/day did not prevent falls compared with 200 IU/day, with doses ≥ 2000 IU/day potentially showing safety concerns.

Objective

To examine associations of achieved and change in 25(OH)D concentrations after 3 months of vitamin D supplementation with fall risk.

Design

Observational analysis of trial data.

Setting

General community.

Participants

A total of 637 adults aged ≥ 70 with baseline 25(OH)D concentrations 10 to 29 ng/mL and elevated fall risk. Three-month on-treatment absolute 25(OH)D; absolute and relative changes from baseline.

Main Outcome Measures

Incident first fall (primary) and first consequential fall (injury or sought medical care) up to 24 months. Cox models were adjusted for sociodemographics, season, Short Physical Performance Battery, and body mass index.

Results

At baseline, mean (SD) age was 77.1 (5.4) years and 25(OH)D was 22.1 (5.1) ng/mL; 43.0% were women and 21.5% non-White. A total of 395 participants experienced ≥ 1 fall; 294 experienced ≥ 1 consequential fall. There was no association between absolute achieved 25(OH)D and incident first fall (30-39 vs < 30 ng/mL hazard ratio [HR], 0.93; 95% CI, 0.74-1.16; ≥40 vs < 30 ng/mL HR, 1.09; 95% CI, 0.82-1.46; adjusted overall P = 0.67), nor absolute or relative change in 25(OH)D. For incident consequential first fall, the HR (95% CI) comparing absolute 25(OH)D ≥ 40 vs < 30 ng/mL was 1.38 (0.99-1.90).

Conclusion

Achieved 25(OH)D concentration after supplementation was not associated with reduction in falls. Risk of consequential falls may be increased with achieved concentrations ≥ 40 ng/mL.

Trial Registration

ClinicalTrials.gov: NCT02166333.

The Vitamin D/Vitamin D receptor (VDR) axis in muscle atrophy and sarcopenia

Muscle atrophy and sarcopenia (the term given to the age-related decline in muscle mass and function), influence an individuals risk of falls, frailty, functional decline, and, ultimately, impaired quality of life. Vitamin D deficiency (low serum levels of 25-hydroxyvitamin D (25(OH)D₃)) has been reported to impair muscle strength and increase risk of sarcopenia. The mechanisms that underpin the link between low 25(OH)D₃ and sarcopenia are yet to be fully understood but several lines of evidence have highlighted the importance of both genomic and non-genomic effects of active vitamin D (1,25-dihydroxyvitamin D (1,25(OH)₂D₃)) and its nuclear vitamin D receptor (VDR), in skeletal muscle functioning. Studies in vitro have demonstrated a key role for the vitamin D/VDR axis in regulating biological processes central to sarcopenic muscle atrophy, such as proteolysis, mitochondrial function, cellular senescence, and adiposity. The aim of this review is to provide a mechanistic overview of the proposed mechanisms for the vitamin D/VDR axis in sarcopenic muscle atrophy.

Necessity of daily 1000-IU vitamin D supplementation for maintaining a sufficient vitamin D status

The changes in the serum 25-hydroxyvitamin D (25(OH)D) concentrations after daily 1000-IU vitamin D intake for 3 months (3-month-VD), 6 months (6-month-VD) and then 6-month cessation of vitamin D in-take (6-month-VD cessation) were examined. The serum 25(OH)D levels in 11 male and 16 female subjects were 12.1±3.5 ng/mL at baseline, increased to 27.1±4.7 ng/mL at 3-month-VD, 28.5±5.1 ng/mL at 6-month-VD and decreased to 16.4±4.0 ng/mL at 6-month-VD cessation. The present study suggested that a vitamin D intake of 1000 IU/day is required to maintain the 25(OH) D concentration at 30 ng/mL or higher without vitamin D intoxication. J. Med. Invest. 69 : 135-140, February, 2022.

Food store accessibility affects nutritional intake through shopping frequency and food intake in middle-aged to older adults in rural Nagasaki, Japan

OBJECTIVES

The food environment is an important determinant of dietary and nutritional intake, but studies thus far have reported mixed results. We examined associations between food store accessibility and nutritional intake among middle-aged to older adults in rural Japan using data from a questionnaire survey of national health insurance enrollees.

METHODS

The survey was conducted in Nagasaki, Japan, for individuals aged 40-74 years. Direct distances from home and food store density were estimated using a geographic information system (GIS). We focused on protein, vitamin D, and calcium intake for their preventive effects on frailty and sarcopenia. To examine the effects of food store accessibility on nutritional intake, we hypothesized a model with a chain of associations of food store accessibility, shopping frequency, food intake frequency, and nutritional intake. We performed a path analyses to explore the food items to be included in the models, associations between the variables, and fitness of the models.

RESULTS

We obtained final models with satisfactory fit indices. The resultant models included significant associations between: 1) accessibility indicators and shopping frequency, 2) shopping frequency and intake frequency for two or four categories of food, and 3) intake frequency and nutritional intake.

CONCLUSIONS

The results demonstrated that accessibility to food stores, assessed in terms of direct distance from home and food store density, can affect the intake of protein, vitamin D, and calcium through the effect on shopping frequency and intake frequency of some categories of food items, among middle-aged to older adults in Nagasaki, Japan.

Evidence and suggestions for establishing vitamin D intake standards in Koreans for the prevention of chronic diseases

BACKGROUND/OBJECTIVES

Vitamin D is produced in the skin during sun exposure and is also ingested from foods. The role of vitamin D needs to be considered in the prevention and management of various diseases. Moreover, since the majority of Koreans spend their days indoors, becoming susceptible to the risk of vitamin D deficiency. The current study aims to prepare a basis for determining dietary reference intake of vitamin D in Korea, by reviewing the evidence against various diseases and risks.

MATERIALS/METHODS

Literature published in Korea and other countries between 2014 and 2018 was prioritized based on their study design and other criteria, and evaluated using the RoB 2.0 assessment form and United States Department of Agriculture Nutrition Evidence Library Conclusion Statement Evaluation Criteria.

RESULTS

Of the 1,709 studies, 128 studies were included in the final systematic analysis after screening. To set the dietary reference intakes of vitamin D based on the selected articles, blood 25(OH)D levels and indicators of bone health were used collectively. Blood vitamin D levels and ultraviolet (UV) exposure time derived from the Korean National Health and Nutrition Examination Survey were analyzed to establish the dietary reference intakes of vitamin D for each stage of the life cycle. The adequate intake levels of vitamin D, according to age and gender, were determined to be in the range of 5–15 μg/day, and the tolerable upper intake level was established at 25–100 μg/day.

CONCLUSIONS

The most important variable for vitamin D nutrition is lifestyle. A balanced diet comprising foods with high contents of vitamin D is important, as is vitamin D synthesis after UV exposure. The adequate intake level of vitamin D mentioned in the 2015 Dietary Reference Intakes for Korean (KDRI) remained unchanged in the 2020 KDRI for the management of vitamin D nutrition in Koreans.

Vitamin D in the Dietary Reference Intakes for Japanese (DRIs) 2020

Dietary Reference Intakes for Japanese (DRIs) are revised every five years. In DRIs 2020, major revision has been made on vitamin D (VD). In DRIs, five indices are defined for nutrients; estimated average requirement (EAR), recommended dietary allowance (RDA) and adequate intake (AI) for the prevention of deficiency/insufficiency, tolerable upper intake level (UL) for avoiding excess intake, and tentative dietary goal for preventing life-style related diseases (DG) for the primary prevention of life-style related diseases. For VD, AI has been determined. VD deficiency causes rickets and osteomalacia. VD insufficiency, milder than deficiency, is a risk for various diseases including osteoporotic fracture. Previously, the basis of AI for VD was the prevention of rickets and osteomalacia, but was changed to the median intake of healthy subjects in DRIs 2005. Recent studies have shown, however, that VD deficiency/insufficiency is quite prevalent, and the above basis is considered inadequate. Then in DRIs 2020, AI was defined as the amount necessary for fracture prevention (15 μg/d) minus that possibly produced in Sapporo during winter in the skin by ultraviolet (5 μg/d). UL and AI for infants were revised in DRIs 2015. For the future DRIs, more clinical and epidemiological studies are urgently needed.

The serum 25(OH)D level and hand grip strength for fall risk assessment among osteoporotic elderly Japanese women

We investigated the relationship between serum 25(OH)D levels, grip strength, and fall score in elderly osteoporotic women for fall risk assessment. Both low serum 25(OH)D and low grip strength were independently associated with increased fall risk. The serum 25(OH)D cutoff specific to increased fall risk was 14 mg/dL (35 nmol/L).

PURPOSE

This study aimed to establish a cutoff value of serum 25-hydroxyvitamin D (25(OH)D) for fall assessment and investigate the relationship between serum 25(OH)D, grip strength, and fall score adjusted for age in osteoporotic elderly Japanese women.

METHODS

This is a cross-sectional study utilizing collected data of osteoporotic elderly (age ≥65 years) female patients. A questionnaire for fall risk assessment was used, in which a score ≥ 6 was determined as increased fall risk. Serum 25(OH)D levels and grip strength were measured, and the cutoff points were calculated by receiver operating curve (ROC) analysis. Logistic regression analysis with age adjustment was conducted for potential risk factors for fall.

RESULTS

After applying eligibility criteria, finally, 349 patients were enrolled. The median patient age was 77.0 years, and the mean serum 25(OH)D level was 15.6 ng/mL (36 nmol/L). Based on the ROC analysis, we defined the cutoff values of serum 25(OH)D level and grip strength as 14 ng/mL (35 nmol/L) and 15 kg, respectively. A multivariate analysis adjusted for age was conducted. Low serum 25(OH)D level and grip strength were independent risk factors for ≥6 fall risk scores.

CONCLUSION

Both low serum 25(OH)D level and low grip strength were independently associated with increased fall risk score in osteoporotic elderly women. The appropriate serum 25(OH)D cutoff specific to the increased fall risk group in this population was 14 mg/dL (35 nmol/L). These findings might be used for the identification of patients with high fall risks. These results should be confirmed in other patient groups.

Epidemiology of the association between serum 25-hydroxyvitamin D levels and musculoskeletal conditions among elderly individuals: a literature review

Background

Vitamin D deficiency is associated with osteoporosis, fracture, muscle weakness, falls, and osteoarthritis in adults. Elderly individuals are more likely to present with poor musculoskeletal conditions. Recently, several epidemiological studies have assessed the correlation between serum 25-hydroxyvitamin D (25(OH)D) levels and musculoskeletal conditions in elderly individuals.

Main text

Osteoporosis is a skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Numerous studies have shown a positive association between serum 25(OH)D levels and bone mineral density. Only a few studies have reported an association between serum 25(OH)D levels and quantitative ultrasound (QUS) parameters. Low serum 25(OH)D level may be a risk factor for hip fracture. However, data on the association between vitamin D deficiency and the incidence of non-hip fracture are contrasting. Falls are a major cause of mortality and morbidity in older adults. Several prospective population-based cohort studies have shown that low 25(OH)D levels are associated with an increased risk of falls. Reduced muscle strength and physical performance are risk factors for adverse events, including disability, institutionalization, and mortality. The role of vitamin D in musculoskeletal functionality (muscle weakness and physical performance) among elderly individuals is still controversial. Osteoarthritis (OA) is the most common form of arthritis and is a leading cause of disability among older adults. Data on the association between serum 25(OH)D levels and OA are contrasting.

Conclusion

Some studies have shown that vitamin D deficiency may be a risk factor for poor musculoskeletal conditions, such as osteoporosis, fracture, muscle weakness, falls, and osteoarthritis in adults. However, other studies did not find an association between serum 25(OH)D levels and musculoskeletal conditions.

Insufficiency of B vitamins with its possible clinical implications

Vitamin deficiency causes classical deficiency diseases such as beriberi and rickets. Vitamin insufficiency, which is milder than deficiency, is a risk for various chronic diseases, but its significance has not been recognized in Japan. Vitamin D insufficiency is quite common in Japan, and a serious risk for osteoporotic fracture through its unbeneficial effect on bone and muscle. Insufficiency of B vitamins has been little studied. However, hyperhomocysteinemia caused by the insufficiency of vitamin B12 or folate is a risk for cardiovascular disease, osteoporotic fracture, and cognitive impairment. Additionally, we have recently reported that vitamin B1 insufficiency is a risk for heart failure in the elderly. The effect of improvement of nutritional status including vitamins is less marked compared to drug treatment, but it costs far less, and is suited for the primary prevention of diseases. Randomized controlled trial is considered the study with the most robust evidence in the evaluation of drug treatment, but more emphasis should be put on the well-designed cohort studies in evaluating the role of nutrients. Vitamin insufficiency is quite prevalent, and vitamin requirement is much higher for its prevention than for the prevention of deficiency.

Vitamin D as a Biomarker of Ill Health among the Over-50s: A Systematic Review of Cohort Studies

Background: The association between circulating levels of vitamin D and the incidence of chronic diseases is known. The identification of vitamin D as a biomarker of physiological/pathological ageing could contribute to expanding current knowledge of its involvement in healthy ageing. Methods: According to PRISMA guidelines, a systematic review was conducted on cohorts studying the role of 25OH-Vitamin D [25(OH)D] and 1,25(OH)₂-Vitamin D [1,25(OH)₂D] concentrations as biomarkers of healthy ageing. We consulted MedLine, Scopus, and Web of Science to search for studies on the association between vitamin D status in populations of originally healthy adults, and outcomes of longevity, illness, and physical and cognitive functionality. The quality of the studies was assessed using the Newcastle Ottawa scale. Results: Twenty cohorts from 24 articles were selected for this review. Inverse associations were found between low 25(OH)D levels and all-cause mortality, respiratory and cardiovascular events, as well as markers relating to hip and non-vertebral fractures. Associations between 1,25(OH)₂D and healthy ageing outcomes gave similar results, although of lower clinical significance. Conclusions: This systematic review pinpoints peculiar aspects of vitamin D as a multidimensional predictor of ill health in the ageing process. Further well-designed controlled trials to investigate whether vitamin D supplement results in superior outcomes are warranted in the future.

Does the Metabolically Healthy Obese Phenotype Protect Adults with Class III Obesity from Biochemical Alterations Related to Bone Metabolism?

Obesity negatively affects the relationship between markers and micronutrients of bone metabolism. Testing the hypothesis that the metabolically healthy obese phenotype might be protected by those alterations was the aim of this study. A cross-sectional study was carried out in adults with class III obesity classified in Metabolically Healthy Obese (MHO) and Metabolically Unhealthy Obese (MUHO), according to the National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (NCEP ATP III) criteria. Anthropometric, biochemical, and clinical variables were analyzed for sample characterization. To evaluate bone metabolism, markers (alkaline phosphatase and parathyroid hormone—PTH) and related nutrients (vitamin D, vitamin B12, calcium, phosphorus, magnesium, potassium and zinc) were analyzed. A total of 223 adults with class III obesity aged 41.20 ± 10.15 years were included. The MHO phenotype was identified in 32.73% of the sample. After logistic regression, it was observed that inadequacies of calcium (OR: 4.11; 95% CI: 2.33–6.66), phosphorus (OR: 3.03; 95% CI: 1.98–5.79), vitamin D (OR: 5.01; 95% CI: 2.92–6.71) and PTH (OR: 5.45; 95% CI: 4.49–6.74) were significantly higher in the MUHO group compared to the MHO Group. This study showed that the MHO phenotype does not protect adults from alterations in markers and micronutrients of bone metabolism. However, the MUHO phenotype presents a higher risk for alterations related to bone metabolism, which can favor the emergence of metabolic bone diseases.

A simple questionnaire for the prediction of vitamin D deficiency in Japanese adults (Vitaimn D Deficiency questionnaire for Japanese: VDDQ-J)

Vitamin D deficiency (VDD) is associated with an increased risk of various diseases. Serum 25-hydroxyvitamin D [25(OH)D] concentration is the best marker for vitamin D status and its concentration < 20 ng/mL indicates VDD. However, its measurement is not easily applicable for the evaluation of vitamin D status in the general population because of its cost. Therefore, we aimed to develop a simple questionnaire for easily identifying the risk of VDD. From the total sample (649 healthy subjects aged 19-70 years), 434 and 215 subjects were randomly assigned to the derivation and the validation cohort, respectively. Prediction model for VDD was developed by backward logistic regression analysis. The regression β coefficients of the significant predictors were transformed into integral numbers and used for the individual score. These individual scores were summed to calculate the total risk score (VDD questionnaire for Japanese score: VDDQ-J score). VDD was present in 54.1% of the total subjects. The model for the prediction of VDD consisted of 7 predictors. Areas under the curve were 0.78 and 0.75 in the data set of internal validation and of the external validation, respectively. The cutoff value was determined to be 31 points (range 0-54) with the sensitivity/specificity and positive predictive value/negative predictive value of 61%/79%, and 81%/57%, respectively. Our VDDQ-J score is easy to answer by the wide range of subjects, and well predicts VDD. This risk score would be useful to identify subjects at risk for VDD both in clinical and epidemiological settings.

Association of Decreased Handgrip Strength with Reduced Cortical Thickness in Japanese Female Patients with Type 2 Diabetes Mellitus

LD-100, a quantitative ultrasonic device, allows us to measure cortical thickness (CoTh). Patients with type 2 diabetes mellitus (T2DM) show high prevalence of sarcopenia. This study aimed to clarify the association of handgrip strength (HGS) with cortical porosis, a major risk for fracture of DM. CoTh and trabecular bone mineral density (TrBMD) at the 5.5% distal radius were assessed in T2DM female patients (n = 122) and non-DM female controls (n = 704) by LD-100. T2DM patients aged older 40 years showed significantly lower HGS and CoTh, but not TrBMD, than non-DM counterparts. Although HGS was significantly and positively correlated with CoTh and TrBMD in T2DM patients, multivariate analysis revealed HGS as an independent factor positively associated with CoTh, but not TrBMD, in T2DM patients, suggesting the preferential association of HGS with cortical, but not trabecular, bone component in T2DM female patients. In conclusion, the present study demonstrated an early decline of HGS in T2DM female patients as compared with non-DM healthy controls after the age of 40 years, which is independently associated with thinner CoTh, but not TrBMD in T2DM patients, and thus suggested that reduced muscle strength associated with DM might be a major factor for cortical porosis development in DM patients.

The impact of exercise and vitamin D supplementation on physical function in community-dwelling elderly individuals: A randomized trial

BACKGROUND

We investigated the impact of exercise and vitamin D supplementation on physical function and locomotor dysfunction in community-dwelling elderly individuals.

METHODS

In total, 148 community-dwelling elderly individuals (aged ≥60 years) who were not taking osteoporosis medications participated in a 24-week intervention. The participants were randomly divided into an exercise group, vitamin D group, and exercise and vitamin D group. The participants and outcome-assessing staff were not blinded to group assignment. Exercise comprised three daily sets each of single-leg standing (1 min/leg/set) and squatting (5-6 repetitions/set); vitamin D supplementation was 1000 IU/day. Participants were contacted every 2 weeks to check on their condition and encourage continued participation. The primary outcome was lower limb muscle strength and mass; secondary outcomes were several physical function measurements, serum 25-hydroxyvitamin D levels, and results of a self-assessment questionnaire completed pre- and post-intervention.

RESULTS

We analyzed data from 45, 42, and 43 participants in the exercise, vitamin D, and exercise and vitamin D groups, respectively, who completed the intervention. Locomotive syndrome, which involves reduced mobility due to locomotive organ impairment, was diagnosed in 99 participants (76.2%). Many physical function measurements improved in all groups. Lower limb muscle mass increased significantly in all three groups, with no significant differences between the groups in the degree of change. The average serum 25-hydroxyvitamin D of all vitamin D-supplemented participants increased from 28.1 ng/ml to 47.3 ng/ml after vitamin D supplementation.

CONCLUSIONS

Both exercise and vitamin D supplementation independently improved physical function and increased muscle mass in community-dwelling elderly individuals. Moreover, the combination of exercise and vitamin D supplementation might further enhance these positive effects.

CLINICAL TRIAL REGISTRY

UMIN Clinical Trial, UMIN000028229.

The Asia-Pacific Clinical Practice Guidelines for the Management of Frailty

OBJECTIVE

To develop Clinical Practice Guidelines for the screening, assessment and management of the geriatric condition of frailty.

METHODS

An adapted Grading of Recommendations, Assessment, Development, and Evaluation approach was used to develop the guidelines. This process involved detailed evaluation of the current scientific evidence paired with expert panel interpretation. Three categories of Clinical Practice Guidelines recommendations were developed: strong, conditional, and no recommendation.

RECOMMENDATIONS

Strong recommendations were (1) use a validated measurement tool to identify frailty; (2) prescribe physical activity with a resistance training component; and (3) address polypharmacy by reducing or deprescribing any inappropriate/superfluous medications. Conditional recommendations were (1) screen for, and address modifiable causes of fatigue; (2) for persons exhibiting unintentional weight loss, screen for reversible causes and consider food fortification and protein/caloric supplementation; and (3) prescribe vitamin D for individuals deficient in vitamin D. No recommendation was given regarding the provision of a patient support and education plan.

CONCLUSIONS

The recommendations provided herein are intended for use by healthcare providers in their management of older adults with frailty in the Asia Pacific region. It is proposed that regional guideline support committees be formed to help provide regular updates to these evidence-based guidelines.

Longitudinal associations between serum 25-hydroxyvitamin D, physical activity, knee pain and dysfunction and physiological falls risk in community-dwelling older adults

AIMS

To describe the longitudinal associations between physiological falls risk, and between-person and within-person effects of 25-hydroxyvitamin D (25OHD), physical activity (PA), knee pain and dysfunction in community-dwelling older people.

METHODS

Data for 1053 participants (51% women; mean age 63 ± 7.4 years) studied at baseline, 2.5, 5, and 10 years were analysed. Falls risk (Z-score) was measured using the Physiological Profile Assessment. Knee pain and dysfunction were assessed using the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC). Moderate-to-vigorous PA (MVPA) was measured using accelerometer. Linear mixed-effect regression models, with adjustment for confounders, were used to estimate the association between physiological falls risk and between-person and within-person effects of PA, 25OHD and WOMAC score.

RESULTS

Between-person effects showed that 10-year average physiological falls risk was lower in participants who had a higher 10-year average 25OHD (β = -0.005 per nmol/l, 95% CI: -0.008, -0.002), log-MVPA (β = -0.16 per minute, 95% CI: -0.22, -0.10) and lower mean WOMAC score (β = 0.005 per-unit score, 95% CI: 0.003, 0.01). Within-person effects showed that a higher physiological falls risk at any time-point was associated with higher than average WOMAC score (β = 0.002 per-unit score, 95% CI: 0.0003, 0.004) and lower than average log-MVPA (β = -0.15 per minute, 95% CI: -0.24, -0.06), but not 25OHD, at the same time-point.

CONCLUSION

Having higher WOMAC global score above an individual's average increases the risk of falling, whereas, increasing one's own MVPA level further reduces their risk of falling. The presence of between-person but not within-person associations for 25OHD suggests the former may be confounded by other factors.

Total 25-hydroxyvitamin D levels predict fracture risk: results from the 15-year follow-up of the Japanese Population-based Osteoporosis (JPOS) Cohort Study

We found that community-dwelling women with 25-hydroxyvitamin D levels <20 ng/mL compared to levels ≥20 ng/mL indicated increased risks for clinical, non-vertebral, and fragility fractures during 5 years. Furthermore, the increased risks of non-vertebral fractures remained significant in 10 and 15 years after adjusting for age and bone mineral density.

INTRODUCTION

We examined whether total 25-hydroxyvitamin D (25[OH]D) levels are associated with fracture risk over 15 years in a Japanese female cohort.

METHODS

Of 1437 community-dwelling women aged ≥50 years in the baseline survey, 1236 provided information regarding fractures during a 15-year follow-up period. The analysis included 1211 women without early menopause or diseases affecting bone metabolism.

RESULTS

Over 15 years, 269 clinical (224 non-vertebral, 149 fragility) fracture events were confirmed. Incidence rates categorized by 25(OH)D levels (<10, 10-20, 20-30, and ≥30 ng/mL) indicated a significant divergence for any clinical fractures in 5 years (log rank test p = 0.016) and for non-vertebral fractures in 5, 10, and 15 years (p < 0.001, p = 0.001, p = 0.017, respectively). Hazard ratios (HRs) for 25(OH)D levels <10 and 10-20 ng/mL compared to levels ≥30 ng/mL during 5 years indicated significances for clinical fractures (HR 4.93 with p = 0.009, HR 3.00 with p = 0.034) and for non-vertebral fractures (HR 6.55 with p = 0.005, HR 3.49 with p = 0.036). Those with levels <20 ng/mL compared to those with levels ≥20 ng/mL indicated significant increased risks for clinical fractures (HR 1.72 with p = 0.010), non-vertebral fractures (HR 2.45 with p < 0.001), and fragility fractures (HR 2.00 with p = 0.032) in 5 years. The HR of non-vertebral fractures for levels <20 ng/mL remained significant during 15 years (HR 1.42 with p = 0.012) after adjustment for age and femoral neck bone mineral density.

CONCLUSIONS

Low 25(OH)D levels, especially <20 ng/mL, were associated with elevated fracture risks in Japanese women.

Associations between serum 25-hydroxyvitamin D3 level and skeletal muscle mass and lower limb muscle strength in Japanese middle-aged subjects

Objectives

One of the important risk factors of falling is decreased muscle mass and muscle strength. Recently, there has been an increasing concern on the role of vitamin D in muscle strength and physical activity. Aim of our study is to examine the relationships between vitamin D status and muscle mass and muscle strength in middle-aged healthy adults.

Methods

Subjects were 40 healthy volunteers aged 42.0 ± 10.6 years old. Evaluation was made for serum vitamin D₃ metabolites including 25-hydroxyvitamin D₃ [25(OH)D₃] and 24,25-dihydroxyvitamin D₃ [24,25(OH)₂D₃] concentrations, lower limb muscle strength, and dietary intake by food frequency questionnaire. Body composition was measured by dual-energy X-ray absorptiometry (DXA), and appendicular skeletal mass index (ASMI) was calculated as skeletal muscle mass/squared height.

Results

70% of the subjects had vitamin D insufficiency/deficiency (serum total 25(OH)D < 20 ng/mL), and female subjects had significantly lower serum total 25(OH)D level compared with males. Vitamin D insufficiency/deficiency group had significantly higher body fat, lower SMI and muscle strength, probably reflecting higher percentage of female subjects. Serum vitamin D₃ metabolites levels were significantly correlated with whole and site-specific ASMI, and lower limb muscle strength, except for the correlation between serum 24,25(OH)₂D₃ concentration and lower limb muscle strength. In addition, serum 25(OH)D₃ level was a positive significant predictor for both ASMI and lower limb muscle strength, while serum 24,25(OH)₂D₃ level was not their significant predictor.

Conclusions

Serum 25(OH)D₃ level was significantly correlated with both skeletal muscle mass and lower limb muscle strength.

Assessment criteria for vitamin D deficiency/insufficiency in Japan - proposal by an expert panel supported by Research Program of Intractable Diseases, Ministry of Health, Labour and Welfare, Japan, The Japanese Society for Bone and Mineral Research and The Japan Endocrine Society [Opinion]

Vitamin D is indispensable for the maintenance of bone and mineral health. Inadequate vitamin D action increases the risk for various musculoskeletal/mineral events including fracture, fall, secondary hyperparathyroidism, diminished response to antiresorptives, rickets/osteomalacia, and hypocalcemia. Its most common cause in recent years is vitamin D deficiency/insufficiency, clinically defined by low serum 25-hydroxyvitamin D [25(OH)D] level. Guidelines for vitamin D insufficiency/deficiency defined by serum 25(OH)D concentrations have been published all over the world. In Japan, however, the information on the associations between serum 25(OH)D and bone and mineral disorders has not been widely shared among healthcare providers, partly because its measurement had not been reimbursed with national medical insurance policy until August 2016. We have set out to collect and analyze Japanese data on the relationship between serum 25(OH)D concentration and bone and mineral events. Integrating these domestic data and published guidelines worldwide, here we present the following assessment criteria for vitamin D sufficiency/insufficiency/deficiency using serum 25(OH)D level in Japan. 1) Serum 25(OH)D level equal to or above 30 ng/mL is considered to be vitamin D sufficient. 2) Serum 25(OH)D level less than 30 ng/mL but not less than 20 ng/mL is considered to be vitamin D insufficient. 3) Serum 25(OH)D level less than 20 ng/mL is considered to be vitamin D deficient. We believe that these criteria will be clinically helpful in the assessment of serum 25(OH)D concentrations and further expect that they will form a basis for the future development of guidelines for the management of vitamin D deficiency/insufficiency.

Assessment criteria for vitamin D deficiency/insufficiency in Japan: proposal by an expert panel supported by the Research Program of Intractable Diseases, Ministry of Health, Labour and Welfare, Japan, the Japanese Society for Bone and Mineral Research and the Japan Endocrine Society [Opinion]

Vitamin D is indispensable for the maintenance of bone and mineral health. Inadequate vitamin D action increases the risk for various musculoskeletal/mineral events including fracture, fall, secondary hyperparathyroidism, diminished response to antiresorptives, rickets/osteomalacia, and hypocalcemia. Its most common cause in recent years is vitamin D deficiency/insufficiency, clinically defined by a low serum 25-hydroxyvitamin D [25(OH)D] level. Guidelines for vitamin D insufficiency/deficiency defined by serum 25(OH)D concentrations have been published all over the world. In Japan, however, the information on the associations between serum 25(OH)D and bone and mineral disorders has not been widely shared among healthcare providers, partly because its measurement had not been reimbursed with national medical insurance policy until August 2016. We have set out to collect and analyze Japanese data on the relationship between serum 25(OH)D concentration and bone and mineral events. Integrating these domestic data and published guidelines worldwide, here, we present the following assessment criteria for vitamin D sufficiency/insufficiency/deficiency using serum 25(OH)D level in Japan. (1) Serum 25(OH)D level equal to or above 30 ng/ml is considered to be vitamin D sufficient. (2) Serum 25(OH)D level less than 30 ng/ml but not less than 20 ng/ml is considered to be vitamin D insufficient. (3) Serum 25(OH)D level less than 20 ng/ml is considered to be vitamin D deficient. We believe that these criteria will be clinically helpful in the assessment of serum 25(OH)D concentrations and further expect that they will form a basis for the future development of guidelines for the management of vitamin D deficiency/insufficiency.