Low 25-hydroxyvitamin D predicts the onset of mobility limitation and disability in community-dwelling older adults: the Health ABC Study

Prevalence and incidence of mobility limitation in Chinese older adults: evidence from the China health and retirement longitudinal study

BACKGROUND

Mobility limitation, a manifestation of impaired intrinsic capacity, is the first obvious sign of functional decline. However, few studies have been conducted on the prevalence and incidence of mobility limitation. This study aimed to estimate the prevalence and incidence of mobility limitation in Chinese older adults (over 60 years old) and evaluate its impact on mortality.

METHODS

The study used two waves of data from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2013. The prevalence and incidence of mobility limitation were assessed using the methods recommended by the World Health Organization in the integrated care for older people guidelines, using the five-time sit-to-stand test as a screening and then the Short Physical Performance Battery assessment for diagnosis. Multivariable logistic regression was used to analyze the association between mobility limitation and death.

RESULTS

Of the 5507 participants with complete baseline data, 1486 had limited mobility, and 4021 had intact mobility at baseline; 4093 participants completed follow-up assessment 2 years later, and 189 died between the baseline and follow-up assessments. Of the 2828 participants with intact mobility at baseline who completed the follow-up mobility assessment, 408 developed mobility limitation. The standardized prevalence was 30.4% (95% CI = 28.8-32.1 %). The standardized incidence of mobility limitation in 2 years was 18.1% (95% CI = 15.8-20.4 %). A total of 189 patients died during the follow-up period. After adjusting for sociodemographic factors and chronic diseases, mobility limitation was associated with an increased risk of death (odds ratio = 1.84, 95% CI = 1.33-2.55, P < .001).

CONCLUSIONS

The standardized prevalence of mobility limitation in Chinese older adults living in the community was 30.4%, and the standardized incidence was 18.1%. Mobility limitation significantly predicts 2-year death in older adults. This suggests that early screening, assessment of intrinsic capacity (particularly locomotion domain) as well as tailored interventions to tackle mobility limitation in older adults might reduce mortality.

The Health, Aging, and Body Composition (Health ABC) Study-Ground-Breaking Science for 25 Years and Counting

BACKGROUND

The Health, Aging, and Body Composition Study is a longitudinal cohort study that started just over 25 years ago. This ground-breaking study tested specific hypotheses about the importance of weight, body composition, and weight-related health conditions for incident functional limitation in older adults.

METHODS

Narrative review with analysis of ancillary studies, career awards, publications, and citations.

RESULTS

Key findings of the study demonstrated the importance of body composition as a whole, both fat and lean mass, in the disablement pathway. The quality of the muscle in terms of its strength and its composition was found to be a critical feature in defining sarcopenia. Dietary patterns and especially protein intake, social factors, and cognition were found to be critical elements for functional limitation and disability. The study is highly cited and its assessments have been widely adopted in both observational studies and clinical trials. Its impact continues as a platform for collaboration and career development.

CONCLUSIONS

The Health ABC provides a knowledge base for the prevention of disability and promotion of mobility in older adults.

Current Evidence on the Association of Micronutrient Malnutrition with Mild Cognitive Impairment, Frailty, and Cognitive Frailty among Older Adults: A Scoping Review

Micronutrient malnutrition is thought to play an important role in the cause of cognitive impairment and physical frailty. The purpose of this scoping review was to map current evidence on the association between micronutrient deficiency in blood and mild cognitive impairment, frailty, and cognitive frailty among older adults. The scoping review was conducted based on the 2005 methodological framework by Arksey and O'Malley. The search strategy for potential literature on micronutrient concentration in blood and cognitive frailty was retrieved based on the keywords using electronic databases (PubMed, Cochrane Library, Google Scholar, Ovid, and Science Direct) from January 2010 to December 2021. Gray literature was also included in the searches. A total of 4310 articles were retrieved and 43 articles were incorporated in the review. Findings revealed a trend of significant association between low levels of B vitamins (folate and vitamin B12), vitamin D, vitamin A, vitamin E, omega 3 fatty acid, and albumin, and high homocysteine levels in blood with an increased risk of mild cognitive impairment among older adults. The results also indicated that low vitamin D levels, albumin, and antioxidants (lutein and zeaxanthin) in blood were significantly associated with frailty among older adults, while β-cryptoxanthin and zeaxanthin in blood were inversely associated with the risk of cognitive frailty. Vitamin D and antioxidants seemed to be targeted nutrients for the prevention of cognitive frailty. In conclusion, a wide range of micronutrient deficiency was associated with either mild cognitive impairment or frailty; however, little evidence exists on the dual impairment, i.e., cognitive frailty. This scoping review can serve as preliminary evidence for the association between micronutrient deficiency in blood and mild cognitive impairment, frailty, and cognitive frailty among older adults and prove the relevancy of the topic for future systematic reviews.

Natural Food for Sarcopenia: A Narrative Review

Sarcopenia is a syndrome characterised by progressive loss of skeletal muscle mass and strength. Proper nutrition is essential for management of sarcopenia. Thus, this article aims to review the association between dietary pattern or food groups consisting of natural food and sarcopenia. A literature search was performed using four databases namely PubMed, Scopus, Sage and ScienceDirect. The search terms used were 'fruits', 'vegetables', 'egg', 'fish', 'chicken', 'protein food', 'ulam', 'fresh herbs', 'sarcopenia', 'elderly and 'older adults'. A total of 18 studies were included in the final review. Adherence to Mediterranean and Japanese dietary pattern were associated with lower prevalence of sarcopenia whereas Western dietary pattern was significantly associated with higher risk of sarcopenia. For food groups, there is a significant association between dietary protein intake and sarcopenia. There are also significant associations between the intake of vegetables, fruits or both vegetables and fruits, and lower risk of sarcopenia. Consumption of natural food comprising of high-quality protein, fruits and vegetables have been associated with protection against muscle wasting and sarcopenia. Therefore, it is possible that a well-planned diet may works just as effectively as or possibly better than individual nutrient supplements for the prevention and treatment for sarcopenia among older adults.

Sex Differences in Vitamin D Status as a Risk Factor for Incidence of Disability in Instrumental Activities of Daily Living: Evidence from the ELSA Cohort Study

Vitamin D deficiency compromises elements underlying the disability process; however, there is no evidence demonstrating the association between vitamin D deficiency and the incidence of disability in instrumental activities of daily living (IADL). We investigated the association between vitamin D deficiency and the risk of incidence of IADL disability separately in men and women. A total of 4768 individuals aged ≥50 years from the English Longitudinal Study of Aging (ELSA) and without IADL disability according to the Lawton scale were available. Vitamin D was evaluated at baseline by serum 25(OH)D concentrations and classified as sufficient (>50 nmol/L), insufficient (>30 to ≤50 nmol/L) or deficient serum (≤30 nmol/L). IADL were reassessed after 4 years. Poisson models stratified by sex and controlled by covariates demonstrated that deficient serum 25(OH)D was a risk factor for the incidence of IADL disability in men (IRR: 1.43; 95% CI 1.02, 2.00), but not in women (IRR: 1.23; 95% CI 0.94, 1.62). Men appear to be more susceptible to the effect of vitamin D deficiency on the incidence of IADL disability, demonstrating the importance of early clinical investigation of serum 25(OH)D concentrations to prevent the onset of disability.

How can dementia and disability be prevented in older adults: where are we today and where are we going?

Ageing of the population, together with population growth, has brought along an ample increase in the number of older individuals living with dementia and disabilities. Dementia is the main cause of disability in old age, and promoting healthy brain ageing is considered as a key element in diminishing the burden of age-related disabilities. The World Health Organization recently launched the first risk reduction guidelines for cognitive impairment and dementia. According to recent estimates, approximately 40% of dementia cases worldwide could be attributable to 12 modifiable risk factors: low education; midlife hypertension and obesity; diabetes, smoking, excessive alcohol use, physical inactivity, depression, low social contact, hearing loss, traumatic brain injury and air pollution indicating clear prevention potential. Dementia and physical disability are closely linked with shared risk factors and possible shared underlying mechanisms supporting the possibility of integrated preventive interventions. FINGER trial was the first large randomized controlled trial indicating that multidomain lifestyle-based intervention can prevent cognitive and functional decline amongst at-risk older adults from the general population. Within the World-Wide FINGERS network, the multidomain FINGER concept is now tested and adapted worldwide proving evidence and tools for effective and easily implementable preventive strategies. Close collaboration between researchers, policymakers and healthcare practitioners, involvement of older adults and utilization of new technologies to support self-management is needed to facilitate the implementation of the research findings. In this scoping review, we present the current scientific evidence in the field of dementia and disability prevention and discuss future directions in the field.

Sex-specific 25-hydroxyvitamin D threshold concentrations for functional outcomes in older adults: PRoject on Optimal VItamin D in Older adults (PROVIDO)

BACKGROUND

Threshold serum 25-hydroxyvitamin D [25(OH)D] concentrations for extraskeletal outcomes are uncertain and could differ from recommendations (20-30 ng/mL) for skeletal health.

OBJECTIVES

We aimed to identify and validate sex-specific threshold 25(OH)D concentrations for older adults' physical function.

METHODS

Using 5 large prospective, population-based studies-Age, Gene/Environment Susceptibility-Reykjavik (n = 4858, Iceland); Health, Aging, and Body Composition (n = 2494, United States); Invecchiare in Chianti (n = 873, Italy); Osteoporotic Fractures in Men (n = 2301, United States); and Study of Osteoporotic Fractures (n = 5862, United States)-we assessed 16,388 community-dwelling adults (10,376 women, 6012 men) aged ≥65 y. We analyzed 25(OH)D concentrations with the primary outcome (incident slow gait: women <0.8 m/s; men <0.825 m/s) and secondary outcomes (gait speed, incident self-reported mobility, and stair climb impairment) at median 3.0-y follow-up. We identified sex-specific 25(OH)D thresholds that best discriminated incident slow gait using machine learning in training data (2/3 cohort-stratified random sample) and validated using the remaining (validation) data and secondary outcomes.

RESULTS

Mean age in the cohorts ranged from 74.4 to 76.5 y in women and from 73.3 to 76.6 y in men. Overall, 1112/6123 women (18.2%) and 494/3937 men (12.5%) experienced incident slow gait, 1098/7011 women (15.7%) and 474/3962 men (12.0%) experienced incident mobility impairment, and 1044/6941 women (15.0%) and 432/3993 men (10.8%) experienced incident stair climb impairment. Slow gait was best discriminated by 25(OH)D <24.0 ng/mL compared with 25(OH)D ≥24.0 ng/mL in women (RR: 1.29; 95% CI: 1.10, 1.50) and 25(OH)D <21.0 ng/mL compared with 25(OH)D ≥21.0 ng/mL in men (RR: 1.43; 95% CI: 1.01, 2.02). Most associations between 25(OH)D and secondary outcomes were modest; estimates were similar between validation and training datasets.

CONCLUSIONS

Empirically identified and validated sex-specific threshold 25(OH)D concentrations for physical function for older adults, 24.0 ng/mL for women and 21.0 ng/mL for men, may inform candidate reference concentrations or the design of vitamin D intervention trials.

Associations Between Complement Components and Vitamin D and the Physical Activities of Daily Living Among a Longevous Population in Hainan, China

Background: Vitamin D and complement components shared some common pathophysiological pathways in the musculoskeletal system, circulation, and metabolism, which were linked to physical function. It is hypothesized that serum complement components may interact with vitamin D in respect of the physical activities of daily living (PADLs). Objective: To investigate if serum complement components 3 (C3), complement components 4 (C4), and 25-hydroxyvitamin D [25(OH)D] associate with PADLs, and to examine whether the association between 25(OH)D levels and PADLs varies at different complement component levels among Chinese centenarians. Methods: This study was conducted in a group of population-based centenarians. PADLs were evaluated using the Barthel Index. Multiple regressions were used to analyze the associations among 25(OH)D, complements C3 and C4, and PADLs. Results: Among 943 participants, 672 (71.3%) had physical dependence (PD). After adjusting for potential confounders, serum 25(OH)D and C3 levels were positively correlated with PADLs, while C4 levels were negatively correlated with PADLs (Ps < 0.05). Serum 25(OH)D levels significantly interacted with both C3 (P for interaction = 0.033) and C4 (P for interaction = 0.006) levels on PADLs. At lower complement component levels, the multivariate odds ratios (ORs) of the upper tertile of vitamin D for PD were 0.32 (95% CI: 0.18-0.55) in the C3 group and 0.29 (95% CI: 0.16-0.50) in the C4 group. At higher complement component levels, the ORs in the C3 and C4 groups were not statistically significant. Conclusions: In a group of population-based Chinese centenarians, we observed that serum complement C3 and 25(OH)D levels were positively associated with PADLs, while C4 was negatively associated with PADLs. The associations between 25(OH)D levels and PADLs were more pronounced in groups with lower serum complement component levels.

Nutritional Supplements to Support Resistance Exercise in Countering the Sarcopenia of Aging

Skeletal muscle plays an indispensable role in metabolic health and physical function. A decrease in muscle mass and function with advancing age exacerbates the likelihood of mobility impairments, disease development, and early mortality. Therefore, the development of non-pharmacological interventions to counteract sarcopenia warrant significant attention. Currently, resistance training provides the most effective, low cost means by which to prevent sarcopenia progression and improve multiple aspects of overall health. Importantly, the impact of resistance training on skeletal muscle mass may be augmented by specific dietary components (i.e., protein), feeding strategies (i.e., timing, per-meal doses of specific macronutrients) and nutritional supplements (e.g., creatine, vitamin-D, omega-3 polyunsaturated fatty acids etc.). The purpose of this review is to provide an up-to-date, evidence-based account of nutritional strategies to enhance resistance training-induced adaptations in an attempt to combat age-related muscle mass loss. In addition, we provide insight on how to incorporate the aforementioned nutritional strategies that may support the growth or maintenance of skeletal muscle and subsequently extend the healthspan of older individuals.

The relationship of serum 25-hydroxyvitamin D concentration with clinical variables in patients with oropharyngeal dysphagia

BACKGROUND & AIMS

The relationship between vitamin D and oropharyngeal dysphagia (OD) is still poorly understood. The aim of this study was to evaluate 25-hydroxyvitamin D [25(OH)D] concentration in patients with OD and to verify its association to nutritional status, functional independence measure (FIM), time of clinical signs (TCS) and OD severity. This is a cross-sectional study conducted with outpatients. Body mass index (BMI), FIM, TCS, causes of OD, comorbidities, penetration-aspiration scale (PAS) and severity scale were evaluated.

METHODS

A multiple linear regression and effect size were performed to evaluate the association between serum 25(OH)D concentration and independent variables.

RESULTS

Forty-eight participants were included, with a mean age of 60.1 ± 15.3 years. The mean of the 25(OH)D concentration was 26.10 ± 12.0 ng/mL. The prevalence of hypovitaminosis D (<30 ng/mL) was 73%. In the multiple linear regression analysis (adjusted for sex, age, BMI, dietary intake and solar radiation), 25(OH)D concentration was significantly related with the TCS (p = 0.01, f² = 0.48). Patients with hypovitaminosis D had a moderate effect (p = 0.08, δ = 0.36) for a lower FIM score.

CONCLUSIONS

These findings indicate that serum 25(OH)D concentration may be related to the TCS and the functional capacity of patients with OD.

Vitamin K Status and Mobility Limitation and Disability in Older Adults: The Health, Aging, and Body Composition Study

BACKGROUND

Vitamin K has been implicated in chronic diseases associated with increased risk for mobility disability, such as osteoarthritis and cardiovascular disease. However, the association between vitamin K status and mobility disability is unknown. Therefore, we examined the association between vitamin K status and incident mobility disability in the Health, Aging, and Body Composition Study.

METHODS

Plasma phylloquinone (vitamin K1) was categorized as <0.5, 0.5-<1.0 and ≥1.0 nmol/L (n = 1,323, 48% male). Plasma ucMGP, which increases when vitamin K status is low, was measured in 716 participants and categorized into tertiles. Mobility limitation and disability, defined as two consecutive semiannual reports of having any or a lot of difficulty walking a one-fourth mile or climbing 10 steps without resting, were assessed over a median 6-10 years of follow-up. Multivariate Cox proportional hazard models were used to evaluate the association between vitamin K status and incident mobility limitation and disability.

RESULTS

Participants with plasma phylloquinone less than 0.5 nmol/L were more likely to develop mobility limitation and disability compared to those with at least 1.0 nmol/L (adjusted HR (95% CI) mobility limitation: 1.27 (1.05-1.53); disability: 1.34 (1.01-1.76)). After further adjustment for knee pain, the associations were partially attenuated (HR (95% CI) mobility limitation: 1.20 (0.99-1.45); disability: 1.26 (0.96-1.67)). Plasma ucMGP was not associated with incident mobility limitation, but was nonlinearly associated with incident mobility disability (HR (95% CI), compared to tertile 1: tertile 2 = 1.64 (1.19-2.27), tertile 3 = 1.17 (0.83-1.66), fully adjusted).

CONCLUSION

Our results suggest vitamin K may be involved in the disablement process in older age. Future studies are needed to confirm our findings and clarify the underlying mechanism.

Motoric cognitive risk syndrome: Integration of two early harbingers of dementia in older adults

Dementia is characterized by a long preclinical phase that may last years to decades before the onset of mild cognitive impairment. Slow gait speed and subjective memory complaint commonly co-occur during this preclinical phase, and each is a strong independent predictor of cognitive decline and dementia. Motoric cognitive risk (MCR) syndrome is a pre-dementia syndrome that combines these two early harbingers of dementia. The risk of cognitive decline or dementia is stronger for MCR than for either slow gait speed or subjective memory complaint alone. Slow gait speed and subjective memory complaint have several common risk factors: cardiovascular disease, diabetes mellitus, abnormal cortisol profiles, low vitamin D levels, brain atrophy with decreased hippocampal volume, and increased deposition of beta-amyloid in the brain. The underlying pathogenesis of MCR remains poorly understood. Metabolomics and proteomics have great potential to provide new insights into biological pathways involved in MCR during the long preclinical phase preceding dementia.

Association between Traditional Japanese Diet Washoku and Sarcopenia in Community-Dwelling Older Adults: Findings from the Kashiwa Study

OBJECTIVES

To identify the dietary patterns among community-dwelling Japanese older adults and to explore the association between these patterns and sarcopenia.

DESIGN

Cross-sectional study.

SETTING

Kashiwa city, Chiba prefecture, Japan.

PARTICIPANTS

Community-dwelling older adults (n = 1241) aged 65 years and over who were not eligible for long-term care.

MEASUREMENTS

Dietary intake was assessed using the brief self-administered diet history questionnaire (BDHQ). Dietary patterns were identified using both principal component analysis and the score on the Japanese diet comprising soybeans and soybean products, fish, vegetables, pickles, mushroom, seaweeds, and fruits. Sarcopenia was defined by the Asian Working Group for Sarcopenia (AWGS) criteria. A binary logistic regression analysis was performed with sarcopenia status as the dependent variable after adjusting for economic status, living alone status, BMI, energy intake, multimorbidity, and physical activity.

RESULTS

Participants' mean age was 74.6 years, and 52.1% were male. According to AWGS criteria, 5.1% had sarcopenia. Three dietary patterns were identified from the principal component analysis. Dietary pattern 1 (DP1), showed high loadings for fish, tofu, vegetables, and fruits which are similar to the side dishes in a typical Japanese diet. Dietary pattern 2 (DP2) had high factor loadings for fish, rice, and miso soup which are main dishes in a typical Japanese diet. Dietary pattern 3 (DP3) had a high factor loading for noodles. Men with the lowest tertile of DP1 score had a higher likelihood of being sarcopenic (Adjusted odds ratio (AOR) 3.67, 95% confidence interval (CI) 1.20-11.2). Women with the lowest tertile of DP2 score had a moderate likelihood of being sarcopenic (AOR 2.71, 95%CI 0.99-7.46). Low adherence to Japanese dietary pattern was associated with prevalence of sarcopenia in both genders.

CONCLUSION

Adherence to a dietary pattern high in foods characteristic of a Japanese diet including fish, soybean products, vegetables, and fruits was associated with low prevalence of sarcopenia in both genders.

Admission 25-Hydroxyvitamin D Levels Are Associated With Functional Status at Time of Discharge from Intensive Care Unit in Critically Ill Surgical Patients

BACKGROUND

Vitamin D status is associated with length of stay (LOS) and discharge destination in critically ill patients. To further understand this relationship, we investigated whether admission 25-hydroxyvitaminD (25OHD) levels are associated with discharge functional status in the intensive care unit (ICU).

METHODS

In this retrospective study, data from 2 surgical ICUs at a large teaching hospital were analyzed. 25OHD levels were measured within 24 hours of ICU admission and Functional Status Score for the ICU (FSS-ICU) was calculated within 24 hours of ICU discharge for all patients. To investigate the association of vitamin D status with FSS-ICU, we constructed linear and logistic regression models, controlling for body mass index, Nutrition Risk in the Critically Ill score, ICU LOS, and cumulative protein or caloric deficit during ICU admission.

RESULTS

Mean 25OHD level and FSS-ICU was 19 (SD 8) ng/mL and 17 (SD 4), respectively, in the analytic cohort (n = 300). Each unit increase in 25OHD level was associated with a 0.2 increment in FSS-ICU (β = .20; 95% CI 0.14-0.25). Patients with 25OHD levels <20 ng/mL had >3-fold risk of low FSS-ICU (<17) compared with patients with 25OHD >20 ng/mL (OR 3.45; 95% CI 1.96-6.08).

CONCLUSIONS

Our results suggest that vitamin D status at admission is associated with discharge FSS-ICU in critically ill surgical patients. Future studies are needed to validate our results, to build upon our findings, and to determine whether optimizing 25OHD levels can improve functional status and other important clinical outcomes in ICU patients.

25(OH) vitamin D and functional outcomes in older adults admitted to rehabilitation units: the safari study

Vitamin D (25(OH)D) deficiency is associated with poor physical performance; little is known about its impact on geriatric rehabilitation. We found a positive non-linear relationship between 25(OH)D and functional gain, stronger in levels < 16 ng/ml (below the cutoff for "deficiency"). An early 25(OH)D dosage may be advisable for this population.

INTRODUCTION

Vitamin D (25(OH)D) deficiency is highly prevalent in older people, and it is associated with poor muscular strength and physical performance. Its impact on functional outcomes during geriatric rehabilitation has been poorly studied. We aim to analyze the association between 25(OH)D and functional recovery in geriatric rehabilitation units.

METHODS

We conducted a prospective multi-center cohort study including patients ≥ 65 years old admitted to 3 geriatric rehabilitation units in Italy and Spain, after orthopedic events or stroke. Outcomes were absolute functional gain (AFG, discharge-admission Barthel index) and ability to walk (AW) at 3 months after admission. The association between 25(OH)D quartiles (Q1-Q2-Q3-Q4) and outcomes was explored using linear or logistic regression models.

RESULTS

We included 420 patients (mean age = 81.2 years [SD = 7.7], 66.4% females, mean 25(OH)D concentration = 13.5 ng/ml [SD = 8.7]) (to convert to nmol/l multiply by 2.496). A non-linear relationship between 25(OH)D and AFG was found, with a stronger association for 25(OH)D levels < 16 ng/ml. Compared to Q1 (25(OH)D ≤ 6 ng/ml), participants in Q3 (25(OH)D 11.5-18.2 ng/ml) had the best AFG and AW (mean AFG [SD], Q1 = 28.9 [27.8], Q2 = 32.5 [23.5], Q3 = 43.1 [21.9], Q4 = 34.5 [29.3], R² = 7.3%; AW, Q1-Q2 = 80%, Q3 = 91%, Q4 = 86%). Regression models adjusted for potential confounders confirmed these results (AGF Q2, β = 2.614, p = 0.49; Q3, β = 9.723, p < 0.01; Q4, β = 4.406, p = 0.22; AW Q2, OR [95% CI] = 1.84 [0.67-5.33]; Q3, OR [95% CI] = 4.01 [1.35-13.48]; Q4, OR [95% CI] = 2.18 [0.81-6.21]).

CONCLUSIONS

In our study, 25(OH)D concentration showed a positive association with functional outcomes at 3 months. The association is stronger below the usual cutoff for "deficiency." Dosage of 25(OH)D concentration may help identify geriatric rehabilitation patients at risk for a worse functional recovery.

Sex, Residence and Fish Intake Predict Vitamin D Status in Chinese Centenarians

OBJECTIVES

This study aims to investigate the prevalence of vitamin D deficiency in Chinese centenarians and to identify the factors associated with vitamin D deficiency.

DESIGN

Cross-sectional population-based study.

SETTING

Hainan province in the south of China.

PARTICIPANTS

943 subjects aged 100 years old and older.

METHODS

Details on sociodemographics and lifestyle characteristics were collected using a structured questionnaire. Anthropometrics and blood samples were obtained. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D concentration < 20ng/mL (50nmol/L).

RESULTS

The overall prevalence of vitamin D deficiency among these 943 centenarians was 39.9% (376 subjects) and the mean serum vitamin D concentrations were 22.7±9.5 (ng/mL). Female centenarians had higher prevalence of vitamin D deficiency than male (44.0% vs. 21.7%, P <0.001). Multivariate logistic regression analyses showed that being female, urban residency, lower body mass index, higher serum parathyroid hormone levels, no fish consumption, and less sun exposure time were all significant and independent determinants of vitamin D deficiency. No significant associations of vitamin D deficiency with ethnic, education, geographic location, tea drinking, alcohol use, or smoking were found in this study.

CONCLUSION

Vitamin D deficiency was common in Chinese centenarians, especially in women. Given that vitamin D deficiency is linked to numerous adverse health outcomes, dietary, outdoor activities and other intervention measures are needed to correct vitamin D deficiency in this population.

Prevalence of functional dependence in Chinese centenarians and its relationship with serum vitamin D status

Background

Functional dependence (FD) and vitamin D deficiency are common conditions in older adults. However, little is known about the relationship between FD and serum vitamin D status in centenarians. The current study was designed to evaluate the prevalence of FD and examine its relationship with serum vitamin D status among centenarians in China.

Subjects and methods

A cross-sectional study of a large sample of Chinese centenarians including 180 men and 822 women was conducted from June 2014 to December 2016. Home interviews, physical examinations, and blood analyses were performed in 958 centenarians following standard procedures. FD was evaluated using the Barthel index of activities of daily living (ADL). Serum 25-hydroxyvitamin D (25OHD) concentrations were measured as a marker of vitamin D status.

Results

The prevalence of centenarians with FD was 71.2%. Vitamin D deficiency, lack of tea consumption, lack of outdoor activities, visual impairment, and fracture were predictors of FD. Centenarians in the lowest quartile of serum 25OHD concentration had an approximately threefold greater likelihood of FD than those in the highest quartile in multiple logistic regression models (OR =2.88; 95% CI 1.75–4.73; P<0.001). The multivariable OR with a 1 ng/mL decrease in serum 25OHD concentration was 1.06 (95% CI 1.04–1.08; P<0.001) for FD.

Conclusion

Serum 25OHD levels have important associations with FD in Chinese centenarians. Future research could focus on the value of intervening in the case of low serum 25OHD levels through vitamin D supplementation and improving ADL in the older population.

The Healthy Nordic Diet and Mediterranean Diet and Incidence of Disability 10 Years Later in Home-Dwelling Old Adults

BACKGROUND/OBJECTIVE

Diet has a major impact on a person's health. However, limited information exists on the long-term role of the whole diet on disability. We investigated the association of the healthy Nordic diet and the Mediterranean diet with incident disability 10 years later.

DESIGN

Longitudinal, with a follow-up of 10 years.

SETTINGS/PARTICIPANTS

A total of 962 home-dwelling men and women from the Helsinki Birth Cohort Study, mean age 61.6 years, who were free of disability at baseline.

MEASUREMENTS

At baseline, 2001-2004, the Nordic diet score (NDS) and modified Mediterranean diet score (mMDS) were calculated using a validated 128-item food-frequency questionnaire. Higher scores indicated better adherence to the diet. Participants' incident disability was assessed during 2011-2013 by a self-reported questionnaire and was based on mobility limitations and difficulties to perform self-care activities. Analyses were performed using logistic regression and adjusted for potential confounding factors.

RESULTS

In total, 94 participants (9.8%) developed mobility limitations and 45 participants (4.7%) developed difficulties in self-care activities during 10 year follow-up. The likelihood of having mobility limitations (odds ratio (OR) 0.42, 95% confidence interval (CI) 0.22-0.80) and difficulties in self-care activities (OR 0.38, 95% CI 0.15-0.94) were lower among those in the highest NDS tertile than among those in the lowest NDS tertile. Greater mMDS was associated with a lower disability incidence; however, the association was not statistically significant.

CONCLUSIONS/IMPLICATIONS

Adherence to the healthy Nordic diet predicts 10-year incidence of mobility limitations and difficulties to perform self-care activities in old age and may thus be protective against disability in Nordic population.

Functional, nutritional and social factors associated with mobility limitations in the elderly: a systematic review

 Objective. To systematically review the prevalence and in­cidence of mobility limitations in the elderly people and their associated factors. Materials and methods. Articles in the electronic literature were searched via PubMed, Scopus, Lilacs, SciELO, PAHO, MedCarib, Repidisca, Wholis, IBCES, PEDro, Medline and Bireme (2012-2016). The instrument STROBE was used to analyze the quality of the work and the PRISMA recommendation was used to structure the review. Results. Nine studies were included. The prevalence of mobility limitations ranged from 58.1 to 93.2% and the inci­dence ranged from 23 to 53.7%. Studies provided evidence of association of mobility limitations in the elderly popula­tion with high BMI, low 25-hydroxy vitamin D, sarcopenia, fragility, chronic pain, functional dependence, advanced age in women, low hip flexion, sedentary lifestyle, and social support difficulties. Conclusion. Mobility limitations in the elderly had high prevalence and incidence, and there was evidence of association with nutritional, functional and social factors.

An Update on Protein, Leucine, Omega-3 Fatty Acids, and Vitamin D in the Prevention and Treatment of Sarcopenia and Functional Decline

Aging is associated with sarcopenia and functional decline, leading to frailty and disability. As a modifiable risk factor, nutrition may represent a target for preventing or postponing the onset of these geriatric conditions. Among nutrients, high-quality protein, leucine, vitamin D, and omega-3 polyunsaturated fatty acids (n-3 PUFA) are of particular interest for their demonstrated effects on skeletal muscle health. This narrative review aims to examine the recent observational and interventional evidence on the associations and the role of these nutrients in the muscle mass, strength, mobility, and physical function of free-living older adults, who are either healthy or at risk of frailty. Recent evidence supports a higher protein intake recommendation of 1.0⁻1.2 g/kg/day in healthy older adults; an evenly distributed mealtime protein intake or minimal protein per meal may be beneficial. In addition, vitamin D supplementation of 800⁻1000 IU, particularly when vitamin D status is low, and doses of ~3 g/day of n-3 PUFA may be favorable for physical function, muscle mass, and strength. Reviewed studies are highly heterogenous, yet the quantity, quality, and timing of intakes should be considered when designing intervention studies. Combined protein, leucine, vitamin D, and n-3 PUFA supplements may convey added benefits and may represent an intervention strategy in the prevention of sarcopenia and functional decline.

Combined Effect of Dynapenia (Muscle Weakness) and Low Vitamin D Status on Incident Disability

BACKGROUND AND OBJECTIVE

There is little epidemiologic evidence considering the combined effect of dynapenia and low 25-hydroxyvitamin D [25 (OH) D] on incident disability. Our aim was to investigate whether the combination of dynapenia and low 25 (OH) D serum levels increases the risk of activities of daily living (ADL) incident disability.

DESIGN

Prospective cohort study.

SETTINGS

English Longitudinal Study of Aging.

PARTICIPANTS

A total of 4630 community-dwelling adults aged 50 years and older without ADL disability at baseline.

MEASUREMENTS

The baseline sample was categorized into 4 groups (ie, nondynapenic/normal 25 (OH) D, low 25 (OH) D only, dynapenic only, and dynapenic/low 25 (OH) D according to their handgrip strength (<26 kg for men and <16 kg for women) and 25 (OH) D (≤50 nmol/L). The outcome was the presence of any ADL disability 2 years after baseline according to the modified Katz Index. Incidence rate ratios (IRRs) adjusted by sociodemographic, behavioral, and clinical characteristics were estimated using Poisson regression.

RESULTS

The fully adjusted model showed that older adults with dynapenia only and those with lower serum levels of 25 (OH) D combined with dynapenia had higher incident ADL disability risk compared with nondynapenic and those with normal serum levels of 25 (OH) D. The IRRs for lower 25 (OH) D serum levels combined with dynapenia were higher than for dynapenia only, however, the confidence intervals (CIs) showed similar effect for these 2 groups. The IRRs were 1.31 for low 25(OH) D only (95% CI 0.99-1.74), 1.77 for dynapenia only (95% CI 1.08-2.88), and 1.94 for combined dynapenia and low 25(OH)D (95% CI 1.28-2.94).

CONCLUSIONS

Dynapenia only and dynapenia combined with low 25 (OH) D serum levels were important risk factors for ADL disability in middle-aged individuals and older adults in 2 years of follow-up.

Nutritional Needs of the Older Adult

Older adults are particularly vulnerable to compromised nutritional status. With advancing age, the consumption of a high-quality, nutritionally dense diet is increasingly essential to optimize health and well-being. Proportionally, macronutrient needs for older adults are similar to younger adults, however overall calorie requirements tend to decline with age. Unique factors influencing food intake should be considered and individualized guidance should be designed to help overcome medical, physical, and social barriers to a healthy diet. The goal for nutrition intervention should ultimately be to promote health and quality of life across the continuum of the aging process.

Physical Performance and Serum 25(OH)vitamin D Status in Community Dwelling Old Mobility Limited Adults: A Cross-Sectional Study

OBJECTIVES

To examine the potential association between serum 25(OH) vitamin D and the performance on the Short Physical Performance Battery (SPPB) including the sub-components; five repeated chair stands test, 4 meters walk test and balance in older mobility-limited community-dwelling men and women.

DESIGN

A cross sectional study was performed in American and Swedish subjects who were examined for potential participation in a combined exercise and nutrition intervention trial. Logistic regression analysis and linear regression analyses were performed to evaluate the association for 25(OH)D with the overall score on the SBBP, chair stand, gait speed and balance.

PARTICIPANTS

Community-dwelling (mean age 77.6 ± 5.3 years) mobility limited American (n=494) and Swedish (n=116) females (59%) and males.

MEASUREMENTS

The SPPB (0-12 points) includes chair stand (s), gait speed (m/s) and a balance test. Mobility limitation i.e., SPPB score ≤ 9 was an inclusion criterion. A blood sample was obtained to measure serum 25(OH)vitamin D concentrations.

RESULTS

No clear association of 25(OH)D with SPPB scores was detected either when 25(OH)D was assessed as a continuous variable or when categorized according to serum concentrations of <50, 50-75 or <75 nmol/L. However, when analyzing the relationship between 25(OH)D and seconds to perform the chair stands, a significant quadratic relationship was observed. Thus, at serum levels of 25(OH)D above 74 nmol/L, higher concentrations appeared to be advantageous for the chair stand test, whereas for serum levels below 74 nmol/L this association was not observed.

CONCLUSION

This cross- sectional study lacked clear association between serum 25(OH)D and physical performance in mobility limited adults. A potentially interesting observation was that at higher serum levels of 25(OH)D a better performance on the chair stand test was indicated.

Low-dose vitamin D supplementation and incident frailty in older people: An eight year longitudinal study

Hypovitaminosis D is associated with frailty, but if vitamin D supplementation may prevent the onset of frailty is poorly known. Therefore, we aimed to investigate whether vitamin D supplementation is associated with a lower risk of frailty. In this longitudinal study, 4,421 individuals at high risk or having knee osteoarthritis free from frailty at baseline (mean age: 61.3, females=58.0%) were followed for 8 years. Details regarding vitamin D supplementation were captured by asking whether the participant took vitamin D during the previous year, at least once per month. Frailty was defined using the Study of Osteoporotic Fracture (SOF) index as the presence of at least two of the following criteria: (i) weight loss≥5% between baseline and any subsequent follow-up visit; (ii) inability to do five chair stands; (iii) low energy level according to the SOF definition. Multivariable Cox's regression analyses, calculating hazard ratios (HRs) with 95% confidence intervals (CIs), were undertaken. At baseline 69.7% took vitamin D supplements in the previous year, with a mean dose of 384±157 IU per day. During the 8-year follow-up, no difference in the incidence of frailty was evident by vitamin D supplementation status at baseline, even after adjusting for 13 baseline confounders (HR=0.95; 95% CI: 0.72-1.25). Similar results were obtained using the propensity score (HR=0.95; 95% CI: 0.71-1.25) or age- and sex-matched controls (HR=1.00; 95% CI: 0.75-1.33). In conclusion, low-dose vitamin D supplementation was not associated with any decreased risk of frailty during eight years of follow-up in a large cohort of North American people. Future large-scale trials with high doses of oral vitamin D and longer follow-up are needed to confirm/refute our findings.

Apolipoprotein E polymorphism and functional disability in Brazilian elders: the Bambuí Health and Aging Study

Numerous studies have associated the apolipoprotein E (apoE) ε4 allele with worse health status, but few have assessed the existence of genotype-dependent variations in functional performance. Among participants in the Bambuí Health and Aging Study, Minas Gerais State, Brazil, 1,408 elderly underwent apoE genotyping. Functionality was assessed with a questionnaire, and individuals were classified as dependent in basic activities of daily living (BADLs), instrumental activities of daily living (IADLs), and mobility. The association between apoE genotype and functional status was assessed by logistic regression, taking confounding factors into account. Presence of ε4 allele was associated with lower odds of mobility deficit (OR = 0.65; 95%CI: 0.47-0.92) in the adjusted analysis. There were no significant differences in relation to presence of dependency in BADLs and IADLs. The reasons are not entirely understood, but they may involve the role of ε4 allele as a "thrifty gene" in a sample exposed to high risk of infectious and nutritional diseases in the past.

Association of low serum 25-hydroxyvitamin D levels with the frailty syndrome in Mexican community-dwelling elderly

OBJECTIVE

Since vitamin D is an important regulator of muscle function, the effect of vitamin D deficiency on frailty syndrome has been recently studied. This cross-sectional study aimed to determine the association between 25(OH)-vitamin D levels and frailty status in Mexican community-dwelling elderly.

METHODS

Sample of 331 community-dwelling elderly aged 70 or older, a subset of those included in the "Coyoacán cohort" were included. 25(OH)-vitamin D assay and frailty status were measured.

RESULTS

Mean age was 79.3 years and 54.1% were women. Those classified as frail were more likely to have lower Mini-Mental State Examination score (p = 0.015), more disability for instrumental activities of daily living (p < 0.001) and for activities of daily living (p < 0.001). Serum 25(OH)-vitamin D levels were lower in the frail subgroup when compared with the non-frail one (p < 0.001). Multivariate logistic regression analyses showed a significant association between intermediate tertile [odds ratios (OR) = 4.13; 95% confidence intervals (CI) 2.00-8.56] or insufficient tertile (OR = 8.95; 95% CI 2.41-33.30) of vitamin D levels and frailty even after adjusting for potential confounders.

CONCLUSION

These results suggest that older adults with low 25(OH)-vitamin D levels are associated with the probability to being frail compared with those with sufficient vitamin D levels.

Vitamin D and Age-Related Health Outcomes: Movement, Mood, and Memory

It has long been recognized that vitamin D plays an important role in calcium homeostasis and musculoskeletal health. More recent evidence supports a role of vitamin D in physical and cognitive function and depressive symptoms through direct effects on skeletal muscle and the brain as well as indirectly through its reported roles in chronic conditions such as cardiovascular disease and diabetes, conditions that frequently lead to declines in physical and cognitive function and depressed mood. The purpose of this review is to summarize the prospective cohort and randomized controlled trial evidence for vitamin D on physical and cognitive function and depressed mood in older adults. Results from both prospective cohort studies and randomized controlled trials of vitamin D supplementation are mixed. Thus, controversy remains over the optimal vitamin D concentration for physical and cognitive function and depressed mood and whether vitamin D supplementation is beneficial for these outcomes.

Vitamin D status is associated with grip strength in centenarians

Low serum concentrations of 25-hydroxyvitamin D (25(OH)D) have been associated with poor physical function in older adults, but few, if any, studies have examined this relationship in the very old. Therefore, the purpose of this study is to examine this relationship in the very old. Serum 25(OH)D concentrations were obtained from 194 centenarians and near centenarians (98 years and older). The associations between 25(OH)D concentrations and measures of physical function were evaluated with unadjusted and adjusted regression models. We found that 35% of centenarians had 25(OH)D concentrations less than 50 nmol/L. Adjusted mean grip strength was lower for centenarians with 25(OH)D concentrations less than 75 nmol/L than for centenarians with higher concentrations (P<0.05). However, there were no differences in the Georgia Centenarian Study (GCS) Composite Scale, a global measure of physical function, between those with higher and lower 25(OH)D concentrations. We conclude that low 25(OH)D concentrations are associated with poor grip strength, but not GCS Composite Scale, in the very old. Considering the high burden of poor physical function in older adults, understanding the relationship between vitamin D and different measures of physical function, including strength, becomes increasingly important.

Frailty and nutrition: searching for evidence

Frailty is a geriatric syndrome that predicts disability, morbidity and mortality in the elderly. Poor nutritional status is one of the main risk factors for frailty. Macronutrients and micronutrients deficiencies are associated with frailty. Recent studies suggest that improving nutritional status for macronutrients and micronutrients may reduce the risk of frailty. Specific diets such as the Mediterranean diet rich in anti-oxidants, is currently investigated in the prevention of frailty. The aim of this paper is to summarize the current body of knowledge on the relations between nutrition and frailty, and provide recommendations for future nutritional research on the field of frailty.

Serum 25-hydroxyvitamin d and the onset of late-life depressive mood in older men and women: the Pro.V.A. study

INTRODUCTION

Biological evidence suggests that vitamin D might be involved in regulating mood. The relationship between 25-hydroxyvitamin D (25OHD) and the onset of depressive symptoms was examined over a 4.4-year follow-up in a sample of older adults.

METHODS

This research was part of the Progetto Veneto Anziani (Pro.V.A.), an Italian population-based cohort study on a total of 1,039 women and 636 men aged 65 and older. Serum 25OHD levels were measured at baseline. Depressive symptoms were assessed with the Geriatric Depression Scale (GDS) at the baseline and during the follow-up. Analyses were adjusted for relevant confounders, including health and performance status.

RESULTS

25OHD levels correlated inversely with baseline GDS scores, but only in women. After controlling for confounders, women deficient in vitamin D (25OHD < 50 nmol/L) had higher GDS scores than those who were replete (25OHD > 75 nmol/L), with mean [SE] GDS scores: 9.57 [0.37] vs 8.31 [0.31], respectively, p = .02. In men, the relationship between 25OHD levels and baseline GDS scores was no longer significant after controlling for covariates. Adjusted hazard ratios and 95% confidence intervals for incident depression in participants who were vitamin D deficient vs replete were not statistically significant (hazard ratio: 0.74, 95% confidence interval [0.47-1.16] in women; hazard ratio: 0.96 95% confidence interval [0.45-2.06] in men).

CONCLUSION

Although an independent inverse association between 25OHD levels and GDS scores emerged for women on cross-sectional analysis, vitamin D deficiency showed no direct effect on the onset of late-life depressive symptoms in our prospectively studied population. Further studies are warranted to clarify the potential influence of vitamin D on psychological health.

Reactive oxygen species production and mitochondrial dysfunction in white blood cells are not valid biomarkers of ageing in the very old

Reliable and valid biomarkers of ageing (BoA) are needed to understand mechanisms, test interventions and predict the timing of adverse health events associated with ageing. Since increased reactive oxygen species (ROS) production and mitochondrial dysfunction are consequences of cellular senescence and may contribute causally to the ageing of organisms, we focused on these parameters as candidate BoA. Superoxide levels, mitochondrial mass and mitochondrial membrane potential in human peripheral blood mononuclear cells (PBMCs) and subpopulations (lymphocytes and monocytes) were measured in participants from the Newcastle 85+ study, a population-based study of the very old (aged 85 years and older). The intra- and inter-assay precision expressed as coefficient of variation (CV) for all parameters was acceptable (3% to 12% and 5 to 22% respectively). All parameters were stable in the short-term (1 week interval) in a sample of control individuals in the PBMCs and lymphocyte subpopulation, however they were unstable in the monocyte subpopulation; this rendered monocytes unreliable for further analysis. There was a significant association between superoxide levels and mitochondrial mass (positive in lymphocytes, p = 0.01) and between superoxide levels and mitochondrial membrane potential (negative in PBMCs, p = 0.01; positive in lymphocytes, p = 0.05). There were also significant associations between superoxide levels and mitochondrial parameters with other markers of oxidative stress-induced cellular senescence (p≤0.04), however some were in the opposite direction to expected. No associations were found between the measured parameters and age-related outcomes, including cognitive impairment, disability, co-morbidity and survival - questioning the validity of these parameters as candidate BoA in the very old.

The role of vitamin D in improving physical performance in the elderly

There is an ongoing debate over the role of serum 25(OH) vitamin D [25(OH)D] levels in maintaining or improving physical performance and muscle strength. Much of the controversy is because of the variability between studies in participants' characteristics, baseline serum 25(OH)D levels, and baseline physical functioning. The aim of this ancillary study conducted within a randomized controlled clinical trial was to investigate whether supplementation with 400 or 2000 IU vitamin D3 daily for 6 months would improve measures of physical performance and muscle strength in a community-dwelling elderly population aged 65 to 95 years. Those with the slowest gait speed improved their ability to do chair-stand tests after vitamin D supplementation. This finding remained significant after controlling for potential confounding variables. There was also an inverse correlation between serum 25(OH)D levels and fat mass index (FMI) among women, suggesting that higher supplementation with vitamin D is needed as weight increases. The results of this study suggest that supplementation with vitamin D may be most beneficial in older populations who have low baseline physical functioning.

C-reactive protein, vitamin D deficiency, and slow gait speed

OBJECTIVES

To evaluate the independent and joint effects of C-reactive protein (CRP) and 25-OH vitamin D (25(OH)D) levels on mobility disability in older persons.

DESIGN

U.S. population-based cross-sectional study.

SETTING

National Health and Nutrition Examination Surveys (2001-2002).

PARTICIPANTS

Individuals aged 50 and older (N = 1,826).

MEASUREMENTS

C-reactive protein (mg/dL), with high CRP defined as ≥ 0.2 mg/dL, and 25(OH)D levels (ng/mL) operationalized as severe deficiency (<10 ng/mL), deficiency (10-19.9 ng/mL), insufficiency (20-29.9 ng/mL), and normal (≥ 30 ng/mL). Mobility disability was operationalized as gait speed of <0.8 m/s while completing a 20-foot walk (6.1 m).

RESULTS

High CRP and low 25(OH)D levels were associated with slow gait speed. Individuals with high CRP levels and severe vitamin D deficiency were more likely to have slow gait speed than were those with neither risk factor (odds ratio = 3.54, 95% confidence interval = 1.42-8.84, P = .007). A significant positive association between vitamin D level and gait speed was found only in those with high CRP in stratified analyses. Whites and blacks showed similar findings as the overall population.

CONCLUSION

These findings provide evidence of a potential joint effect of vitamin D and CRP on gait speed, suggesting that evaluation and correction of vitamin D levels may be especially important in individuals with high CRP levels.

Vitamin D: beyond bone

In recent years, vitamin D has been received increased attention due to the resurgence of vitamin D deficiency and rickets in developed countries and the identification of extraskeletal effects of vitamin D, suggesting unexpected benefits of vitamin D in health and disease, beyond bone health. The possibility of extraskeletal effects of vitamin D was first noted with the discovery of the vitamin D receptor (VDR) in tissues and cells that are not involved in maintaining mineral homeostasis and bone health, including skin, placenta, pancreas, breast, prostate and colon cancer cells, and activated T cells. However, the biological significance of the expression of the VDR in different tissues is not fully understood, and the role of vitamin D in extraskeletal health has been a matter of debate. This report summarizes recent research on the roles for vitamin D in cancer, immunity and autoimmune diseases, cardiovascular and respiratory health, pregnancy, obesity, erythropoiesis, diabetes, muscle function, and aging.

Association between serum 25-hydroxyvitamin d levels, bone geometry, and bone mineral density in healthy older adults

PURPOSE

The association between serum 25-hydroxyvitamin D values and cortical/trabecular bone parameters in older adults has been incompletely explored. This study was designed to investigate the relationship between serum 25-hydroxyvitamin D levels and bone parameters for the tibia and radius using peripheral quantitative computed tomography in free-living healthy older adults.

METHODS

The study involved 134 older adults attending a twice-weekly low-intensity fitness program. In addition to clinical history and serum parameters, we assessed fat-free mass using dual-energy X-ray absorptiometry, total bone and cortical bone cross-sectional areas, and trabecular and cortical bone mineral density for the tibia and radius by peripheral quantitative computed tomography.

RESULTS

After applying multivariate linear regression models, adjusting for sex, age, body mass index, fat mass and fat-free mass, and creatinine, the association between 25-hydroxyvitamin D and bone parameters was significant for total bone and cortical bone cross-sectional areas in the radius (partial R (2) = 0.05 and 0.09, respectively) and for trabecular bone mineral density and cortical bone cross-sectional area in the tibia (partial R (2) = 0.11 and 0.02, respectively).

CONCLUSION

These findings support the idea that serum 25-hydroxyvitamin D levels and bone parameters are linked in older adults. Longitudinal studies are needed to establish whether vitamin D levels over time are associated with changes in these parameters.