Vitamin D and muscle strength throughout the life course: a review of epidemiological and intervention studies

Is serum 25-hydroxyvitamin D deficiency a risk factor for the incidence of slow gait speed in older individuals? Evidence from the English longitudinal study of ageing

AIMS

Cross-sectional studies demonstrate an association between low serum levels of vitamin D and slower gait speed in older individuals. However, longitudinal studies remain inconclusive. This study investigates whether vitamin D deficiency and insufficiency are risk factors for the incidence of slowness.

MATERIALS AND METHODS

A total of 2815 participants from the English Longitudinal Study of Ageing (ELSA), aged ≥60 years and with a baseline gait speed >0.8 m/s, were followed for six years. Baseline serum levels of vitamin D [25(OH)D] were categorized as "sufficiency" (>50 nmol/L), "insufficiency" (>30 and ≤50 nmol/L) or "deficiency" (≤30 nmol/L). Gait speed was reassessed at four and six years of follow-up to identify incident cases of slowness (walking speed ≤0.8 m/s). A Poisson regression model, adjusted for sociodemographic, behavioural and clinical characteristics at baseline, was conducted to determine the association between serum 25(OH)D levels and the risk of slowness.

RESULTS

The incidence densities of slowness per 1000 person-years were 67.4 (95% CI: 60.93-74.64) for sufficiency, 76.7 (95% CI: 68.30-86.22) for insufficiency and 90.7 (95% CI: 78.46-104.92) for deficiency. Serum 25(OH)D deficiency was associated with a 22% increase in the risk of slowness (IRR: 1.22; 95% CI: 1.01-1.49) compared with serum 25(OH)D sufficiency. No significant association was observed for serum 25(OH)D insufficiency.

CONCLUSIONS

Serum 25(OH)D deficiency is a risk factor for the incidence of slowness in older individuals, suggesting that maintaining sufficient 25(OH)D levels could be a strategic approach to minimise long-term mobility impairment.

Physical activity and vitamin D in children: a review of impacts on bone health and fitness

OBJECTIVES

This review explores the relationship between physical activity and serum 25-hydroxyvitamin D (25(OH)D) levels in children and adolescents, highlighting the importance of vitamin D for bone health and muscle function.

CONTENT

A narrative mini review was conducted by searching PubMed, Google Scholar, and Scopus for studies published from January 2000 to April 2024, focusing on children aged 5-18 years. Ten studies were reviewed, including five cross-sectional, three population-based, one longitudinal, and one randomized controlled trial. Overall, physically active children and teens were more likely to maintain sufficient 25(OH)D levels and demonstrated better physical fitness, especially in muscle strength, compared to their less active peers. One study linked higher vitamin D levels to increased bone mineral content in active adolescents, while another reported a positive connection between vitamin D and bone density. Risk factors for deficiency included limited sun exposure, low physical activity, sedentary behavior, and obesity, with the latter group being more prone to low vitamin D levels, which were negatively associated with fat mass. Interventions that increased physical activity were found to improve vitamin D levels.

SUMMARY AND OUTLOOK

Regular physical activity, especially outdoor exercise, is associated with healthier vitamin D levels in children, supporting better bone health and physical fitness.

Vitamin D status and muscle strength in a pan-European cohort of children and adolescents with normal weight and overweight/obesity

This aimed to investigate associations between the vitamin D status and handgrip strength in children and adolescents considering weight status. Participants aged 7 to < 16 years from the European IDEFICS/I.Family cohort were included. Serum 25-hydroxyvitamin D [25(OH)D] and handgrip strength were measured in 2013/2014. In multivariable logistic regression models, we investigated the association of vitamin D status with handgrip strength adjusted for demographic variables, BMI z-score, sports club membership, screen time and UV intensity. Vitamin D-sufficient children had higher odds for a high handgrip strength (OR = 1.92, 95%-CI: 1.12, 3.30), but this association was limited to children with thinness/normal weight (OR = 2.60, 95%-CI: 1.41-4.81). Children with overweight (OR = 2.64, 95%-CI: 2.00, 3.49) and obesity (OR = 4.53, 95%-CI: 2.93, 7.02) were more likely to have a high handgrip strength than thin/normal weight children.

CONCLUSIONS

The positive association of vitamin D with muscle strength in our study is limited to children with low and normal BMI. In children with overweight or obesity, the higher muscle strength seems to superimpose the association with vitamin D. Overall, our results indicate the importance of sufficient levels of vitamin D and offers physical activity perspectives for children with overweight and obesity.

STUDY REGISTRATION

ISRCTN: https://doi.org/10.1186/ISRCTN62310987 .

WHAT IS KNOWN

• Studies have shown a positive association between vitamin D status and handgrip strength in older adults while studies in children and adolescents are scarce. • Conflicting results were found on whether overweight and obesity are associated with reduced or increased handgrip strength compared to normal weight.

WHAT IS NEW

• The results of this large pan-European study in children and adolescents indicate that a sufficient vitamin D status is associated with better handgrip strength, particularly in participants with thinness/normal weight. • Children with overweight and obesity have a higher handgrip strength as compared to children with thinness/normal weight which seems to superimpose the positive association between vitamin D status and handgrip strength in this group.

Associations between Vitamin D Status and Polysomnographic Parameters in Adults with Obstructive Sleep Apnea

Vitamin D deficiency (VDD) may be associated with obstructive sleep apnea (OSA) presence and is more pronounced with increasing OSA severity; however, the relationship between these two entities remains unclear. This was a cross-sectional study among 262 adults with in-hospital-attended polysomnography-diagnosed OSA and no additional major comorbidities, aiming to explore possible associations between serum 25-hydroxyvitamin D [25(OH)D] levels and polysomnographic parameters. Data on demographics, medical history, anthropometric indices, and lifestyle habits were collected at enrolment. Serum 25(OH)D was evaluated using chemiluminescence, with VDD defined as 25(OH)D < 20 ng/mL. VDD was observed in 63% of the participants. Serum 25(OH)D correlated negatively with apnea-hypopnea index and other polysomnographic indices (all p < 0.05). In logistic regression analysis, adjusting for age, sex, smoking, body mass index, physical activity, dietary vitamin D intake, and season of blood sampling, serum 25(OH)D was associated with lower odds of severe OSA [odds ratio (95% confidence interval): 0.94 (0.90-0.98)]. In the same multivariate model, VDD was associated with ~threefold higher odds of severe OSA [2.75 (1.38-5.48)]. In stratified analyses, VDD predicted OSA severity in the group of participants ≥50 y [3.54 (1.29-9.68)] and among those with body mass index ≥ 30 kg/m2 [3.38 (1.52-7.52)], but not in the younger and non-obese adults. This study provides further evidence of an inverse association between vitamin D levels and OSA severity and underscores the importance of considering vitamin D status as a potential modifiable factor in the comprehensive management of OSA.

Association of magnesium and vitamin D status with grip strength and fatigue in older adults: a 4-week observational study of geriatric participants undergoing rehabilitation

BACKGROUND

Low magnesium and vitamin D levels negatively affect individuals' health.

AIMS

We aimed to investigate the association of magnesium status with grip strength and fatigue scores, and evaluate whether this association differs by vitamin D status among older participants undergoing geriatric rehabilitation.

METHODS

This is a 4-week observational study of participants aged ≥ 65 years undergoing rehabilitation. The outcomes were baseline grip strength and fatigue scores, and 4-week change from baseline in grip strength and fatigue scores. The exposures were baseline magnesium tertiles and achieved magnesium tertiles at week 4. Pre-defined subgroup analyses by vitamin D status (25[OH]D < 50 nmol/l = deficient) were performed.

RESULTS

At baseline, participants (N = 253, mean age 75.7 years, 49.4% women) in the first magnesium tertile had lower mean grip strength compared to participants in the third tertile (25.99 [95% CI 24.28-27.70] vs. 30.1 [95% CI 28.26-31.69] kg). Similar results were observed among vitamin D sufficient participants (25.54 [95% CI 22.65-28.43] kg in the first magnesium tertile vs. 30.91 [27.97-33.86] kg in the third tertile). This association was not significant among vitamin D deficient participants. At week 4, no significant associations were observed between achieved magnesium tertiles and change in grip strength, overall and by vitamin D status. For fatigue, no significant associations were observed.

CONCLUSIONS

Among older participants undergoing rehabilitation, magnesium status may be relevant for grip strength, particularly among vitamin D sufficient individuals. Magnesium status was not associated with fatigue, regardless of vitamin D status.

STUDY REGISTRATION

Clinicaltrials.gov, NCT03422263; registered February 5, 2018.

25-hydroxyvitamin D level is associated with greater grip strength across adult life span: a population-based cohort study

OBJECTIVE

Maintaining muscle function throughout life is critical for healthy ageing. Although in vitro studies consistently indicate beneficial effects of 25-hydroxyvitamin D (25-OHD) on muscle function, findings from population-based studies remain inconclusive. We therefore aimed to examine the association between 25-OHD concentration and handgrip strength across a wide age range and assess potential modifying effects of age, sex and season.

METHODS

We analysed cross-sectional baseline data of 2576 eligible participants out of the first 3000 participants (recruited from March 2016 to March 2019) of the Rhineland Study, a community-based cohort study in Bonn, Germany. Multivariate linear regression models were used to assess the relation between 25-OHD levels and grip strength while adjusting for age, sex, education, smoking, season, body mass index, physical activity levels, osteoporosis and vitamin D supplementation.

RESULTS

Compared to participants with deficient 25-OHD levels (<30 nmol/L), grip strength was higher in those with inadequate (30 to <50 nmol/L) and adequate (≥50 to ≤125 nmol/L) levels (ßinadequate = 1.222, 95% CI: 0.377; 2.067, P = 0.005; ßadequate = 1.228, 95% CI: 0.437; 2.019, P = 0.002). Modelling on a continuous scale revealed grip strength to increase with higher 25-OHD levels up to ~100 nmol/L, after which the direction reversed (ßlinear = 0.505, 95% CI: 0.179; 0.830, P = 0.002; ßquadratic = -0.153, 95% CI: -0.269; -0.038, P = 0.009). Older adults showed weaker effects of 25-OHD levels on grip strength than younger adults (ß25OHDxAge = -0.309, 95% CI: -0.594; -0.024, P = 0.033).

CONCLUSIONS

Our findings highlight the importance of sufficient 25-OHD levels for optimal muscle function across the adult life span. However, vitamin D supplementation should be closely monitored to avoid detrimental effects.

The short-term effect of vitamin D supplementation on the response to muscle and liver damages indices by exhaustive aerobic exercise in untrained men: a quasi-experimental study

BACKGROUND

Exercise-induced muscle damage typically caused by unaccustomed exercise results in pain, soreness, inflammation, and muscle and liver damages. Antioxidant supplementation might be a useful approach to reduce myocytes and hepatocytes damages. Therefore, the present study was conducted to investigate the effect of short-term vitamin D (Vit D) supplementation on the response to muscle and liver damages indices by Exhaustive Aerobic Exercise (EAE) in untrained men.

METHODS

In this clinical trial, 24 untrained men were randomly divided into experimental (Exp; n = 12) and control (C; n = 12) groups. Exp received 2000 IU of Vit D daily for six weeks (42 days), while C daily received a lactose placebo with the same color, shape, and warmth percentage. Two bouts of EAE were performed on a treadmill before and after six weeks of supplementation. Anthropometric characteristics (Bodyweight (BW), height, Body Fat Percentage (BFP), Body Mass Index (BMI), waist to hip ratio (WHR)) were measured at the Pre 1 and Pre 2. Blood samples were taken to measure the Creatine Kinase (CK), Lactate Dehydrogenase (LDH), Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Gamma-Glutamyl Transferase (GGT), Alkaline Phosphatase (ALP), and Vit D levels at four stages: Pre 1 (before the first EE session), Post 1 (after the first EE session), Pre 2 (before the second EE session), and Post 2 (after the second EE session). The data were analyzed using repeated-measures ANOVA, Bonferroni's post hoc test, independent t test, and dependent t-test at the significant level of P < 0.05 using SPSS version 26.

RESULTS

The results show significant differences between Exp and C in alterations of BW (P = 0.039), BMI (P = 0.025), BFP (P = 0.043), and WHR (P = 0.035). The results showed that EAE increased muscle and liver damage indices and Vit D (P < 0.05). Compared with C, the results of the independent t-test showed significantly lower ALT (P = 0.001; P = 0.001), AST (P = 0.011; P = 0.001), GGT (P = 0.018; P = 0.001), and ALP (P = 0.001; P = 0.001); while significantly higher Vit D (P = 0.001, P = 0.001) in the Exp in both Pre 2 and Post 2; receptivity. The independent t test showed significantly lower ALT (P = 0.001; P = 0.001), AST (P = 0.011; P = 0.001), GGT (P = 0.018; P = 0.001), and ALP (P = 0.001; P = 0.001) and considerably greater Vit D (P = 0.001, P = 0.001) in the Exp in both Pre 2 and Post 2 compared to C. The results of an independent t test showed that LDH and CK levels in the Exp were significantly lower than those in the Post 2 (P = 0.001).

CONCLUSIONS

Short-term Vit D supplementation could prevent myocytes and hepatocytes damage induced by EAE.

Association between Polymorphisms in Vitamin D Pathway-Related Genes, Vitamin D Status, Muscle Mass and Function: A Systematic Review

An association between vitamin D level and muscle-related traits has been frequently reported. Vitamin D level is dependent on various factors such as sunlight exposure and nutrition. But also on genetic factors. We, therefore, hypothesize that single nucleotide polymorphisms (SNPs) within the vitamin D pathway-related genes could contribute to muscle mass and function via an impact on vitamin D level. However, the integration of studies investigating these issues is still missing. Therefore, this review aimed to systematically identify and summarize the available evidence on the association between SNPs within vitamin D pathway-related genes and vitamin D status as well as various muscle traits in healthy adults. The review has been registered on PROSPERO and was conducted following PRISMA guidelines. In total, 77 studies investigating 497 SNPs in 13 different genes were included, with significant associations being reported for 59 different SNPs. Variations in GC, CYP2R1, VDR, and CYP24A1 genes were reported most frequently, whereby especially SNPs in the GC (rs2282679, rs4588, rs1155563, rs7041) and CYP2R1 genes (rs10741657, rs10766197, rs2060793) were confirmed to be associated with vitamin D level in more than 50% of the respective studies. Various muscle traits have been investigated only in relation to four different vitamin D receptor (VDR) polymorphisms (rs7975232, rs2228570, rs1544410, and rs731236). Interestingly, all of them showed only very low confirmation rates (6-17% of the studies). In conclusion, this systematic review presents one of the most comprehensive updates of the association of SNPs in vitamin D pathway-related genes with vitamin D status and muscle traits in healthy adults. It might be used for selecting candidate SNPs for further studies, but also for personalized strategies in identifying individuals at risk for vitamin D deficiency and eventually for determining a potential response to vitamin D supplementation.

Food for Special Medical Purposes and Nutraceuticals for Pain: A Narrative Review

Introduction

The present paper focuses on the possible contribution of food compounds to alleviate symptomatic pains. Chronic pain can more easily be linked to anticipatory signals such as thirst and hunger than it is to sensory perceptions as its chronicity makes it fall under the behavioural category rather than it does senses. In fact, pain often negatively affects one’s normal feeding behavioural patterns, both directly and indirectly, as it is associated with pain or because of its prostrating effects.

Nutritional Compounds for Pain

Several nutraceuticals and Foods for Special Medical Purposes (FSMPs) are reported to have significant pain relief efficacy with multiple antioxidant and anti-inflammatory properties. Apart from the aforementioned properties, amino acids, fatty acids, trace elements and vitamins may have a role in the modulation of pain signals to and within the nervous system.

Conclusion

In our opinion, this review could be of great interest to clinicians, as it offers a complementary perspective in the management of pain. Trials with well-defined patient and symptoms selection and a robust pharmacological design are pivotal points to let these promising compounds become better accepted by the medical community.

Seasonal variability of the vitamin D effect on physical fitness in adolescents

Studies investigating the relationship between vitamin D and physical fitness in youth have provided inconsistent findings. Recent evidence indicates that the expression of receptors and vitamin D-modulated genes in young subjects has a seasonal profile. Therefore, we investigated the role of vitamin D on physical fitness across seasons in a total of 977 male adolescents. Anthropometrics, lifestyle, dietary habits, biochemical profiles and physical fitness were studied. Multiple linear regression models, including pairwise interaction terms involving total 25-OH-vitamin D, were fitted. The interacting effect of season and total 25-OH-vitamin D had a significant influence on physical fitness performance (spring and total 25-OH-vitamin D: ß 0.19, SE 0.07, p = 0.007; summer and total 25-OH-vitamin D: ß 0.10, SE 0.06, p = 0.11; autumn and total 25-OH-vitamin D: ß 0.18, SE 0.07, p = 0.01), whereas the main effect of total 25-OH-vitamin D alone was not significant (p = 0.30). Body fat percentage, recreational physical activity level, time spent per day gaming/TV-watching, smoking, and hemoglobin levels were also related to the physical fitness performance score. Future studies should further explore the role of seasonal-dependent effects of vitamin D on health.

Vitamin D status is associated with muscular strength in a nationally representative sample of US youth

AIM

To evaluate the association between serum 25-hydroxyvitamin D (25OHD) and muscular strength in a nationally representative sample of US youth.

METHODS

Participants (n = 3350) were 6- to 18-y-olds from 2011 to 2014 National Health and Nutrition Examination Survey. Relative handgrip strength was quantified using age- and sex-specific z-scores. Poor strength was defined as those <25th percentile. Multivariate general linear and logistic models were used to compare strength and poor strength status by clinically relevant groupings of 25OHD.

RESULTS

Approximately 20.2% of youth had 25OHD <50 nmol/L. Mean relative strength was highest for those at ≥75 nmol/L of 25OHD. The percentage of boys/girls with poor strength in the <50 nmol/L, 50-74.9 nmol/L and ≥75 nmol/L groups was 34.9%/32.3%, 25.8%/28.2% and 14.0%/15.8%, respectively. The odds of boys and girls with <50 nmol/L 25OHD having poor strength were 2.8 (95% CI: 1.4, 5.5) and 3.4 (1.7, 6.8) times higher compared to those with ≥75 nmol/L, respectively.

CONCLUSION

Higher levels of circulating vitamin D were associated with higher relative strength, and poor strength was more prevalent when 25OHD was <75 nmol/L. These findings highlight the value of vitamin D for the muscle-bone unit and potential extraskeletal ramifications.

The effect of vitamin D supplementation on the muscle damage after eccentric exercise in young men: a randomized, control trial

Background

Vitamin D contributes to the optimal functioning of muscles. This study was designed to determine the modulating effect of vitamin D supplementation on the degree of muscle cell damage caused by eccentric exercise in young men.

Methods

60 male volunteers (20–24 years old) taking part in this study were divided in two groups - with suboptimal (S) and optimal (O;) 25(OH)D plasma levels. These groups were randomly subdivided into groups with vitamin D supplementation (experimental: SE and OE) and controls (SC and OC). Before the supplementation (Test I) and after 3 months (Test II), participants were subjected to two rounds of eccentric exercise tests on a declined treadmill (running speed corresponded 60% VO2peak determined in each subject in incremental exercise test). During each test, blood samples used for determination of 25(OH)D, Il-1β, myoglobin (Mb) levels and CK, LDH activity were taken at three timepoints: before the test, 1 h and 24 h after it ended.

After distribution normality testing (Saphiro-Wilk test), statistical analyses were performed. Non-parametric: Kruskal-Wallis test and the Wilcoxon test were applied, and the Dunn-Bonferroni test as a post-hoc test.

Results

In all groups, after 3 months, higher concentrations of 25(OH)D were indicated (SE p = 0.005; SC p = 0.018; OE p = 0.018; OC p = 0.028). SE and SC groups showed higher baseline concentrations of Il-1β and significantly higher concentrations of this interleukin after 1 h compared to groups with an optimal 25(OH)D level. After supplementation, the SE group reacted with a similar jump in concentration of Il-1β as the OC and OE groups. The change after 1 h after exercise in Test II was significantly different from that from Test I (p = 0.047) in SE group. Lower Mb concentrations indicated 1 h after exercise in Test II for SC and SE groups were indicated. CK activity did not differentiate the studied groups. Plasma calcium and phosphate disorders were also not indicated.

Conclusions

The study has shown that vitamin D doses determined from the plasma concentration of 25(OH)D of individuals to match their specific needs can significantly reduce muscle cell damage induced by eccentric exercise.

Impact of vitamin D and vitamin D receptor TaqI polymorphism in primary human myoblasts

The CC-genotype of the VDR polymorphism TaqI rs731236 has previously been associated with a higher risk of developing myopathy compared to TT-carriers. However, the mechanistic role of this polymorphism in skeletal muscle is not well defined. The effects of vitamin D on patients genotyped for the VDR polymorphism TaqI rs731236, comparing CC and TT-carriers were evaluated. Primary human myoblasts isolated from 4 CC-carriers were compared with myoblasts isolated from 4 TT-carriers and treated with vitamin D in vitro. A dose-dependent inhibitory effect on myoblast proliferation and differentiation was observed concurrent with modifications of key myogenic regulatory factors. RNA-sequencing revealed a Vitamin D dose-response gene signature enriched with a higher number of VDR-responsive elements (VDREs) per gene. Interestingly, the greater the expression of muscle differentiation markers in myoblasts the more pronounced was the Vitamin D-mediated response to suppress genes associated with myogenic fusion and myotube formation. This novel finding provides a mechanistic explanation to the inconsistency regarding previous reports of the role of vitamin D in myoblast differentiation. No effects in myoblast proliferation, differentiation or gene expression were related to CC vs. TT carriers. Our findings suggest that the VDR polymorphism TaqI rs731236 comparing CC vs. TT carriers did not influence the effects of vitamin D on primary human myoblasts and that vitamin D inhibits myoblast proliferation and differentiation through key regulators of cell cycle progression. Future studies need to employ strategies to identify the primary responses of vitamin D that drive the cellular response towards quiescence.

Effect of Vitamin D on Cognitive Functions in Older Adults: 24-Week Follow-Up Study

The purpose of this study is to assess the effect of vitamin D replacement on cognitive function in older adults. A total of 560 patients who underwent comprehensive geriatric assessment including Global cognitive assessment, Basic Activities of Daily Living (BADL), and Instrumental Activities of Daily Living (IADL) twice in 6-month period were retrospectively reviewed. Oral cholecalciferol was replaced to patients with vitamin D deficiency routinely. In baseline cognitive scores, BADL-IADL scores were lower in the severe deficiency group than in the deficiency and adequate groups (P < .05). With regard to the relation between changes in cognitive functions, BADL-IADL scores on the 6-month versus baseline, no difference was determined in patients with and without dementia (P > .05). Vitamin D replacement may not improve cognitive performance in older adults, even if vitamin D is raised to adequate level, suggesting that longer term replacement therapy may be needed to improve cognitive function.

Functional capacity, renal function and vitamin D in community-dwelling oldest old

PURPOSE

The aim of this study was to evaluate the association between the decline in estimated glomerular filtration rate (eGFR) and serum 25(OH)D with the physical and mental functional capacity of elderly individuals aged 80 years or older.

METHODS

We evaluated the functional capacity in its multidomain aspects: Geriatric Depression Scale (GDS), Instrumental Activities of Daily Living (IADL), Mental State Mini-Exam (MMSE), Verbal Fluency Test (VF), handgrip strength and time to sit and rise from a chair five times, combined creatinine and cystatin C-based eGFR and 25(OH)D levels in 205 independent asymptomatic and community-dwelling elderly subjects in a cross-sectional study.

RESULTS

Every 1 year of life, there was reduction of about 10% chance of adequate performance in functional capacity. Each 1 ml/min/m² in eGFR was associated with 2% better chance of adequate performance in the IADL. We found no association between eGFR and cognition. Serum 25(OH)D between 15.00 and 22.29 ng/ml increased the chance of better performance in VF, IADL, handgrip strength and sit and rise from the chair compared to the lower level of serum vitamin D.

CONCLUSIONS

Decreased renal function associated with age compromises the ability to perform activities for independent life in the community, but we did not observe influence in specific domains of cognition and physical performance. Low serum level of 25(OH)D appears to be a marker of greater risk of functional decline than eGFR measurement in independent oldest old dwelling in the community.

Effects of dietary patterns and low protein intake on sarcopenia risk in the very old: The Newcastle 85+ study

Background

Sarcopenia, a progressive age-related loss of skeletal muscle mass and strength, leads to disability, falls, and hospitalisation. Individual variation in sarcopenia onset may be partly explained by lifestyle factors such as physical activity and diet. Healthy dietary patterns (DPs) have been linked to better physical functioning in older adults, but their role in sarcopenia in the very old (aged ≥85) is unknown.

Aims

To investigate the association between DPs and the risk of sarcopenia over 3 years, and to determine whether protein intake influences this relationship in community-dwelling older adults from the Newcastle 85 + Study.

Methods

The analytic sample consisted of 757 participants (61.2% women) who had dietary assessment at baseline. After two-step clustering with 30 food groups to derive DPs, we used logistic regression to determine the risk of prevalent and incident sarcopenia across DPs in all participants, and in those with low (<1 g/kg adjusted body weight/day [g/kg aBW/d]) and good protein intake (≥1 g/kg aBW/d).

Results

We identified three DPs (DP1: ‘Low Red Meat’, DP2: ‘Traditional British’ and DP3: ‘Low Butter’) that varied by unsaturated fat spreads/oils, butter, red meat, gravy and potato consumption. Compared with participants in DP3, those in DP2 had an increased risk of prevalent (OR = 2.42, 95% CI: 1.15–5.09, p = 0.02) but not 3-year incident sarcopenia (OR = 1.67, 0.59–4.67, p = 0.33) adjusted for socio-demographic, anthropometry, health and lifestyle factors. Furthermore, DP2 was associated with an increased risk of prevalent sarcopenia at baseline (OR = 2.14, 1.01–4.53, p = 0.05) and 3-year follow-up (OR = 5.45, 1.81–16.39, p = 0.003) after adjustment for key covariates in participants with good protein intake.

Conclusion

A DP high in foods characteristic of a traditional British diet (butter, red meat, gravy and potato) was associated with an increased risk of sarcopenia even when overall protein intake was good. The results need to be replicated in other cohorts of the very old to understand the role of DPs in sarcopenia onset and management.

Association between nutritional blood-based biomarkers and clinical outcome in sarcopenia patients

BACKGROUND

Although several micronutrients deficiency were reported to be associated with poor muscle function, however information on sarcopenia patients is still lacking. The aim of this report was to measure some micronutrients blood-based status in sarcopenia patients during both acute illness and recovery.

DESIGN

We assessed nutritional status of randomly selected hospitalised patients using anthropometric, haematological and biochemical data at baseline, 6 weeks and at 6 months. Sarcopenia was diagnosed from low muscle mass and low muscle strength using anthropometric measures based on the European Working Group criteria. Micronutrient status was compared between sarcopenia patients and those without sarcopenia over a 6 months period.

RESULTS

Forty-four out of 432 patients (10%) were diagnosed with sarcopenia on admission. Patients diagnosed with sarcopenia had lower micronutrients concentrations compared to those patients without sarcopenia however, the results were statistically significant only for baseline serum albumin, red cell folate and plasma zinc (p < 0.05). Lycopene, retinol, red cell folate and zinc were also significantly lower in sarcopenia patients at 6 weeks. Sarcopenia patients readmitted to hospital had poor baseline micronutrient status compared with sarcopenia patients stayed in the community during the 6-months follow up period but differences were not statistically significant. Both baseline serum albumin and plasma zinc were significantly higher in sarcopenia patients who were alive compared with those died at 6 months follow up.

CONCLUSION

Baseline serum albumin and plasma zinc concentrations were lower in patients diagnosed with sarcopenia compared to those without sarcopenia, and also in sarcopenia patients who died compared with those alive at 6 months follow up.

Winter vitamin D3 supplementation does not increase muscle strength, but modulates the IGF-axis in young children

PURPOSE

To explore whether muscle strength, the insulin-like growth factor axis (IGF-axis), height, and body composition were associated with serum 25-hydroxyvitamin D [25(OH)D] and affected by winter vitamin D supplementation in healthy children, and furthermore to explore potential sex differences.

METHODS

We performed a double-blind, placebo-controlled, dose-response winter trial at 55ºN. A total of 117 children aged 4-8 years were randomly assigned to either placebo, 10, or 20 µg/day of vitamin D₃ for 20 weeks. At baseline and endpoint, we measured muscle strength with handgrip dynamometer, fat mass index (FMI), fat free mass index (FFMI), height, plasma IGF-1, IGF-binding protein 3 (IGFBP-3), and serum 25(OH)D.

RESULTS

At baseline, serum 25(OH)D was positively associated with muscle strength, FFMI, and IGFBP-3 in girls only (all p < 0.01). At endpoint, baseline-adjusted muscle strength, FMI and FFMI did not differ between intervention groups. However, baseline-adjusted IGF-1 and IGFBP-3 were higher after 20 µg/day compared to placebo (p = 0.043 and p = 0.006, respectively) and IGFBP-3 was also higher after 20 µg/day compared to 10 µg/day (p = 0.011). Children tended to be taller after 20 µg/day compared to placebo (p = 0.064). No sex interactions were seen at endpoint.

CONCLUSIONS

Avoiding the winter-related decline in serum 25(OH)D may influence IGF-1 and IGFBP-3 in children. Larger trials are required to confirm these effects, and the long-term implication for linear growth.

Vitamin D and calcium supplementation, skeletal muscle strength and serum testosterone in young healthy adult males: Randomized control trial

BACKGROUND

Cholecalciferol and/or calcium supplementation might increase skeletal muscle strength and serum testosterone in young adult males.

OBJECTIVE

We performed a randomized control trial assessing the effect of cholecalciferol/calcium on skeletal muscle strength and serum testosterone in vitamin D deficient young males.

DESIGN

Two-by-two factorial RCT.

SUBJECT AND INTERVENTION

Two-hundred and twenty-eight young males were block-randomized to (i) double-placebo, (ii) calcium/placebo, (iii) cholecalciferol/placebo and (iv) cholecalciferol/calcium. Doses for cholecalciferol were 60 000 IU/wk for 8 weeks followed by 60 000 IU/fortnightly, and doses for elemental calcium were 500 mg/twice daily for 6 months. A total of 180 subjects completed the study protocol. Their  ean age, body mass index and baseline 25(OH)D were 20.2 ± 2.2 years, 23.0 ± 3.6 kg/m² and 21.5 ± 9.5 nmol/L, respectively.

MEASUREMENTS

Handgrip (primary outcome), pinch-grip strength, distance walked in 6 minutes, dyspnoea-score, quality of life by Short Form 36, serum 25(OH)D, 1,25(OH)₂ D, iPTH, total testosterone and free androgen index (FAI).

RESULTS

After intervention, mean serum 25(OH)D was >75.0 nmol/L in cholecalciferol groups. However, the handgrip strength (29.7 ± 4.4, 29.3 ± 4.6, 30.6 ± 5.0 and 28.8 ± 4.3 kg, P = .28) was comparable in the 4 groups. Subgroups analysis among subjects with baseline serum 25OH)D < 25.0 and <12.0 nmol/L showed similar results. The mean serum testosterone decreased significantly at 6 months; however, delta change was similar in 4 groups. Change in handgrip strength and other outcomes was similar in 4 groups with and without adjustment for delta testosterone and FAI.

CONCLUSIONS

Six months of cholecalciferol/calcium supplementation had no significant effect on skeletal muscle strength and serum testosterone in young adult males.

Vitamin D and Ageing

One hundred years has passed since the discovery of vitamin D as the active component of cod-liver oil which cured the bone disease rickets. Since then our knowledge of vitamin D has expanded tremendously and has included recognition of the importance of UV radiation as a source of the vitamin as well as the discovery of the vitamin as a nutrient, a pro-hormone and a potent steroid hormone with a major role in calcium and bone metabolism. In the last 25 years or so, the discovery of the vitamin D receptor in over 30 different body tissues together with the existence of the alpha-1-hydroxylase enzyme in these tissues provided evidence of a pleiotropic role of vitamin D outside its classical role in the skeleton. These important discoveries have provided the basis for the increasing interest in vitamin D in the context of nutritional requirements for health including the prevention of chronic diseases of ageing. The recent publication of the Dietary Reference Intake report on vitamin D and calcium by the North American Institute of Medicine (IOM) is the most comprehensive report to date on the basis for setting nutritional requirements for vitamin D. This chapter will summarize the nutritional aspects of vitamin D and discuss the changes in vitamin D metabolism and requirements with ageing. It will summarize key evidence on the relationship between vitamin D status and some of the main ageing related health outcomes including bone, muscle and cognitive health as well as survival focusing on the published literature in very-old adults (those >= 85 years of age).

Studying Impact of Nutrition on Growth (SING): a prospective cohort for comparing the health outcomes of young children with the dietary quality score

INTRODUCTION

This study aims to explore the prospective association between the dietary quality (DQ) of preschoolers and their health status in Hong Kong, with the body mass index as the main outcome variable.

METHODS AND ANALYSIS

This prospective cohort study has recruited 3539 children aged between 2 and 4 years old, with a follow-up period of 4 years. Their diet was reported by their parents by a 3-day food diary, and their body weight and height were measured yearly with standardised instruments. Questionnaires were administered to parents to acquire information of the children's prenatal development and dietary intake before their age of 2 years and of their baseline lifestyle and family backgrounds. The DQ was measured by the Healthy Eating Index as a continuous scale, while the exposure was defined as having a higher dietary quality score. Data were analysed using SPSS V.24. Linear and logistic regressions were used to examine the association of those predictive factors to the outcomes. Generalised estimating equations will be used to examine the longitudinal changes of the outcomes. A pilot study has been conducted, the preliminary results from which are presented in this cohort profile.

ETHICS AND DISSEMINATION

This study has been approved by the Joint Chinese University of Hong Kong and New Territory East Cluster Clinical Research Ethics Committee (CREC Ref No: 2013-632). Written informed consent was obtained from all subjects. The results will be published in due course.

Associations of dietary patterns with bone mass, muscle strength and balance in a cohort of Australian middle-aged women

Influences of dietary patterns on musculoskeletal health are poorly understood in middle-aged women. This cross-sectional analysis from a cohort of 347 women (aged 36-57 years) aimed to examine associations between dietary patterns and musculoskeletal health outcomes in middle-aged women. Diet was measured by the Cancer Council of Victoria FFQ. Total body bone mineral content (TB BMC), femoral neck and lumbar spine bone density (dual-energy X-ray absorptiometry), lower limbs muscle strength (LMS) and balance tests (timed up and go test, step test, functional reach test (FRT) and lateral reach test) were also measured. Exploratory factor analysis was used to identify dietary patterns and scores for each pattern generated using factor loadings with absolute values ≥0·20. Associations between food pattern scores and musculoskeletal outcomes were assessed using multivariable linear regression. Three dietary patterns were identified: 'Healthy' (high consumption of a plant-based diet - vegetables, legumes, fruit, tomatoes, nuts, snacks, garlic, whole grains and low intake of high-fat dairy products), 'high protein, high fat' (red meats, poultry, processed meats, potatoes, cruciferous and dark-yellow vegetables, fish, chips, spirits and high-fat dairy products) and 'Processed foods' (high intakes of meat pies, hamburgers, beer, sweets, fruit juice, processed meats, snacks, spirits, pizza and low intake of cruciferous vegetables). After adjustment for confounders, Healthy pattern was positively associated with LMS, whereas Processed foods pattern was inversely associated with TB BMC and FRT. The associations were not significant after accounting for multiple comparisons. There were no associations with any other outcomes. These results suggest that maintaining a healthy diet could contribute to bone acquisition, muscle strength and balance in adult life. However, while they provide some support for further investigating dietary strategies for prevention of age-related loss of muscle and deterioration in balance, the exploratory nature of the analyses means that confirmation in longitudinal studies and/or trials with pre-specified hypotheses is needed.

Vitamin D and Cardiorespiratory Fitness in the General Population: A Systematic Review

Abstract. Background: Up to now, the association between vitamin D and cardiorespiratory fitness (CRF) is still inconsistent and there is a lack of a comprehensive review on this topic. Aim: To systematically review the literature including both observational studies and randomized controlled trials (RCTs) on the association between vitamin D and CRF in the general population. Methods: The literature was investigated by exploring databases of PubMed, EMBASE, Scopus and ISI Web of Science as well as a manual search up to April 2017 by using related MeSH terms and key words. All the English-language articles that were conducted in the general population without any restriction on age range of participants and date of publication were included in the study. Results: Among the 731 records which were found initially, a total of 20 articles including 18 cross-sectional studies and 2 RCTs fulfilled the inclusion criteria. Among the cross-sectional studies, findings on the association between serum 25(OH) D and CRF were incongruent. Additionally, studies which had reported significant results varied remarkably in terms of sample size, study population and the effect size of the association. In addition, RCTs found no significant improvement in CRF following vitamin D supplementation. Conclusion: Overall, evidence from cross-sectional studies does not support a strong association between vitamin D and CRF, although a number of studies demonstrated modest positive associations. Furthermore, limited RCTs did not confirm such an association. Further high quality research is needed to obtain a definite conclusion on this topic. “

Vitamin D Status, Muscle Strength and Physical Performance Decline in Very Old Adults: A Prospective Study

Mixed reports exist about the role of 25-hydroxyvitamin D (25(OH)D) in muscle ageing and there are few prospective studies involving the very old (aged ≥ 85) who are at highest risk of low 25(OH)D, loss of muscle mass and strength, and physical performance decline. In the Newcastle 85+ Study (n = 845), we aimed to determine the association between 25(OH)D season-specific quartiles (hereafter SQ1–SQ4), grip strength (GS) and physical performance decline (Timed Up-and-Go Test, TUG) over 5 years using mixed models. In the time-only models with linear and quadratic slopes, SQ1 and SQ4 of 25(OH)D were associated with weaker GS initially in men (SQ1: β (SE) = −2.56 (0.96); SQ4: −2.16 (1.06)) and women (SQ1: −1.10 (0.52); SQ4: −1.28 (0.50)) (all p ≤ 0.04). In the fully adjusted models, only men in SQ1 had a significant annual decline in GS of 1.41 kg which accelerated over time (−0.40 (0.1)), (both p ≤ 0.003) compared with those in combined middle quartiles. Only women in SQ1 and SQ4 of 25(OH)D had worse TUG times initially, but the rate of TUG decline was not affected. Low baseline 25(OH)D may contribute to muscle strength decline in the very old and particularly in men.

Association between serum uric acid concentrations and grip strength: Is there effect modification by age?

BACKGROUND

Given that some of the deleterious effects of uric acid (UA) on health are greater in younger than in older subjects, and that age is strongly associated with skeletal muscle composition and function, this study tested the hypothesis that the association between UA and muscle strength differs by age.

METHODS

Cross-sectional analysis with 3595 individuals who participated in NHANES 2011-2012. Serum uric acid was determined by the uricase-peroxidase technique. Grip strength was calculated as the average of the best measure obtained in each hand with a Takei digital grip strength dynamometer. Linear regression models were adjusted for the main confounders.

RESULTS

In individuals aged 20-40 years, the beta coefficients (95% CI) of muscle strength as dependent variable and UA as independent variable comparing the second and third to the lowest tertile of UA were -0.45 kg (-1.46; 0.57) and -2.36 kg (-3.27; -1.44), respectively, p-linear trend ≤0.01. By contrast, in subjects aged 40-60 years the corresponding beta coefficients were 0.21 kg (-1.00; 1.42) and -0.45 kg (-2.10; 1.20), p-linear trend: 0.60; and for subjects ≥60 years they were 0.58 kg (-3.27; 1.65) and 1.57 kg (0.63; 2.50), p-linear trend <0.01. These results held after numerous sensitivity analyses.

CONCLUSION

The association between UA and muscle strength differed depending on age: while a negative link was observed in adults aged 20-40 years, this relationship disappeared later in life, and was reversed after the age of 60. Future research should evaluate if uric acid targets for individuals with hyperuricemia should consider patients age and muscle strength.

Impact of chemotherapy on medium-term physical function and activity of older breast cancer survivors, and associated biomarkers

OBJECTIVE

Chemotherapy is less often prescribed in older individuals due to concerns about post-treatment morbidity and quality of life. We evaluated the physical performance of breast cancer survivors treated with and without adjuvant chemotherapy.

MATERIALS AND METHODS

We conducted a case-control study in 56 estrogen receptor positive breast cancer survivors (BCS) on adjuvant aromatase inhibitors 1-2years after definitive surgery. Cases had received adjuvant chemotherapy (n=27; age 70.5±3.6years) versus age-matched controls who had not (n=29; age 70.0±4.3years). Measures of grip strength, physical activity and performance, walking speed, fatigue, and self-reported physical function were collected. Biological correlates of inflammation, frailty and markers of DNA and RNA oxidation were compared.

RESULTS

Grip strength (controls: 21±7.4 vs.

CASES

29.7±5.0kg, p=0.20), physical activity (5403±3204 vs. 6801±9320steps/day, p=0.45), physical performance (short physical performance battery score: 10.1±1.8 vs. 10.4±1.1, p=0.52) and long-distance walking speed (1.2±0.21 vs. 1.3±0.41m/s, p=0.17) were similar between the two groups. Self-reported physical function was marginally lower in cases than controls (controls: 72±24 vs.

CASES

57±34AU, p=0.07). Fatigue disruptiveness was not different between groups (controls: 11.1±13.0 vs.

CASES

15.7±16.2AU, p=0.24). Similarly, the inflammation, oxidation, and frailty markers did not present a significant difference between groups, except for vitamin D levels (p=0.04).

CONCLUSION

Older women who received chemotherapy reported having slightly lower physical function, but a similar physical performance compared to women who did not. These data suggest that older BCS treated with chemotherapy recover to an extent similar to survivors who only received hormonal therapy.

High Dose Vitamin D Administration in Ventilated Intensive Care Unit Patients: A Pilot Double Blind Randomized Controlled Trial

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First double blind RCT of vitamin D therapy in mechanically ventilated patients.

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Treatment with placebo, 250,000 IU or 500,000 IU enteral vitamin D3 was well tolerated.

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Significant increase in plasma 25(OH)D from baseline to day 7.

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Significant decrease in hospital length of stay for vitamin D3 treated subjects.

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No change in plasma LL-37 according to treatment group.

Background

There is a high prevalence of vitamin D deficiency in the critically ill patient population. Several intensive care unit studies have demonstrated an association between vitamin D deficiency [25-hydroxyvitamin D (25(OH)D) < 20 ng/mL] and increased hospital length of stay (LOS), readmission rate, sepsis and mortality.

Material and Methods

Pilot, double blind randomized control trial conducted on mechanically ventilated adult ICU patients. Subjects were administered either placebo, 50,000 IU vitamin D₃ or 100,000 IU vitamin D₃ daily for 5 consecutive days enterally (total vitamin D₃ dose = 250,000 IU or 500,000 IU, respectively). The primary outcome was plasma 25(OH)D concentration 7 days after oral administration of study drug. Secondary outcomes were plasma levels of the antimicrobial peptide cathelicidin (LL37), hospital LOS, SOFA score, duration of mechanical ventilation, hospital mortality, mortality at 12 weeks, and hospital acquired infection.

Results

A total of 31 subjects were enrolled with 13 (43%) being vitamin D deficient at entry (25(OH)D levels < 20 ng/mL). The 250,000 IU and 500,000 IU vitamin D₃ regimens each resulted in a significant increase in mean plasma 25(OH)D concentrations from baseline to day 7; values rose to 45.7 ± 19.6 ng/mL and 55.2 ± 14.4 ng/mL, respectively, compared to essentially no change in the placebo group (21 ± 11.2 ng/mL), p < 0.001. There was a significant decrease in hospital length of stay over time in the 250,000 IU and the 500,000 IU vitamin D₃ group, compared to the placebo group (25 ± 14 and 18 ± 11 days compared to 36 ± 19 days, respectively; p = 0.03). There was no statically significant change in plasma LL-37 concentrations or other clinical outcomes by group over time.

Conclusions

In this pilot study, high-dose vitamin D3 safely increased plasma 25(OH)D concentrations into the sufficient range and was associated with decreased hospital length of stay without altering other clinical outcomes.

Effect of Dietary Patterns on Muscle Strength and Physical Performance in the Very Old: Findings from the Newcastle 85+ Study

BACKGROUND

Healthy diet has been associated with better muscle strength and physical performance in cross-sectional studies of older adults but the effect of dietary patterns (DP) on subsequent decline, particularly in the very old (aged 85+), has not been determined.

OBJECTIVE

We investigated the association between previously established DP and decline in muscle strength and physical performance in the very old.

DESIGN

791 participants (61.8% women) from the Newcastle 85+ Study were followed-up for change in hand grip strength (HGS) and Timed Up-and Go (TUG) test over 5 years (four waves 1.5 years apart). Mixed models were used to determine the effects of DP on muscle strength and physical performance in the entire cohort and separately by sex.

RESULTS

Previously we have established three DP that varied in intake of red meats, potato, gravy and butter and differed with key health and social factors. HGS declined linearly by 1.59 kgF in men and 1.08 kgF in women (both p<0.001), and TUG slowed by 0.13 log10-transformed seconds (log10-s) in men and 0.11 log10-s in women per wave after adjusting for important covariates (both p<0.001), and also showed a nonlinear change (p<0.001). Men in DP1 ('High Red Meat') had worse overall HGS (β = -1.70, p = 0.05), but men in DP3 ('High Butter') had a steeper decline (β = -0.63, p = 0.05) than men in DP2 ('Low Meat'). Men in DP1 and women in DP3 also had overall slower TUG than those in DP2 (β = 0.08, p = 0.001 and β = 0.06, p = 0.01, respectively), but similar rate of decline after adjusting for sociodemographic, lifestyle, health, and functioning factors. The results for HGS and TUG were not affected by participants' cognitive status.

CONCLUSIONS

DP high in red meats, potato and gravy (DP1), or butter (DP3) may adversely affect muscle strength and physical performance in later life, independently of important covariates and cognitive status.

The pathogenetic bases of sarcopenia

Aging is accompanied by involuntary loss of skeletal muscle mass, strength and function, called sarcopenia. The mechanisms underlying the development of sarcopenia are not completely understood and most likely multi-factorial, but significant progress has been made over the past few years to identify some of the major contributors. Besides life style-related factors, as diet and physical activity, sarcopenia seems to be also determined by hormonal dysregulation, chronic inflammatory status, ectopic adipose tissue accumulation, neurological and vascular changes associated with aging. The present mini-review focused on the basic factors that primarily impact muscle homeostasis in older subjects. A better understanding of cellular mechanism leading to sarcopenia is required to establish evidence-based intervention in order to prevent onset of symptoms associated with sarcopenia and to extend the time free from disability in older adults.