Effects of a long-term vitamin D and calcium supplementation on falls and parameters of muscle function in community-dwelling older individuals

Skeletal muscle performance and ageing

The world population is ageing rapidly. As society ages, the incidence of physical limitations is dramatically increasing, which reduces the quality of life and increases healthcare expenditures. In western society, ~30% of the population over 55 years is confronted with moderate or severe physical limitations. These physical limitations increase the risk of falls, institutionalization, co-morbidity, and premature death. An important cause of physical limitations is the age-related loss of skeletal muscle mass, also referred to as sarcopenia. Emerging evidence, however, clearly shows that the decline in skeletal muscle mass is not the sole contributor to the decline in physical performance. For instance, the loss of muscle strength is also a strong contributor to reduced physical performance in the elderly. In addition, there is ample data to suggest that motor coordination, excitation-contraction coupling, skeletal integrity, and other factors related to the nervous, muscular, and skeletal systems are critically important for physical performance in the elderly. To better understand the loss of skeletal muscle performance with ageing, we aim to provide a broad overview on the underlying mechanisms associated with elderly skeletal muscle performance. We start with a system level discussion and continue with a discussion on the influence of lifestyle, biological, and psychosocial factors on elderly skeletal muscle performance. Developing a broad understanding of the many factors affecting elderly skeletal muscle performance has major implications for scientists, clinicians, and health professionals who are developing therapeutic interventions aiming to enhance muscle function and/or prevent mobility and physical limitations and, as such, support healthy ageing.

The relationship of Physical performance and Osteoporosis prevention with vitamin D in older African Americans (PODA)

RATIONALE

Vitamin D deficiency is associated with bone loss, poor muscle strength, falls and fracture. This information in older African Americans (AAs) is sparse.

OBJECTIVE

The study of the relationship of Physical performance, Osteoporosis prevention with vitamin D in older African Americans (PODA) is a randomized, double-blind, placebo-controlled 3-year trial examining the effect of vitamin D on bone loss and physical performance in older AA women.

METHODS

260 healthy AA women aged >60years were assigned to receive placebo or vitamin D₃. Initial vitamin D₃ dose was determined by the baseline serum 25OHD level, and adjusted further to maintain serum 25OHD between 30 and 69ng/ml. Subjects with baseline 25OHD levels ≤8ng/ml or ≥26ng/ml were excluded. Objective measures of neuromuscular strength [Short Physical Performance Battery (SPPB), grip strength and 6-minute walking distance (6MWD)] and bone mineral density (BMD) were obtained.

RESULTS

SPPB gait speed, grip strength and 6MWD showed a significant positive correlation with free 25OHD. 1pg/ml increase in free 25OHD predicted a 32% increase in the odds of having higher gait speed and a 1.42lb. increase in grip strength. No significant differences in BMI, BMD, muscle mass, grip strength, serum total 25OHD and free 25OHD were observed between groups. None of the measures of physical performance showed an association with baseline serum 25OHD.

CONCLUSIONS

This is the first study to show an association between free 25OHD and physical performance. These findings indicate a positive relationship of free 25OHD with gait speed and grip strength in older AA women. Further studies are needed to understand the role of free 25OHD.

Effect of Vitamin D on Falls and Physical Performance

Recent understanding has highlighted the importance of extraskeletal role of vitamin D. Despite numerous observational and interventional studies over the last two decades, the apparent divergent clinical findings have intensified the controversy regarding this role of vitamin D in older adults. This article reviews the existing literature and summarizes the current knowledge of vitamin D status and vitamin D supplementation on falls and physical performance, describes the putative mechanisms underlying this association, and reflects on the controversy surrounding vitamin D recommendations in older adults.

Dementia and fragility fractures: Issues and solutions

Dementia and fragility fractures are two conditions that pose significant morbidity and mortality to the elderly population. The occurrence of the 'gerontic' boom as a result of improved healthcare meant a continued increase in the prevalence of fragility fractures and dementia. This represents a major public health problem with significant socioeconomic repercussions. It is therefore important for healthcare professionals to gain a better understanding on the relationship between these two commonly co-existing conditions. In this review, we present the available literature surrounding the relationship between fragility fractures and dementia, and the common challenges faced in the management of these two conditions. Combining evidence from the literature along with our current clinical practice, we propose a management pathway aimed at early diagnosis, prevention and management of these two often co-existing conditions. This alongside with a multidisciplinary approach will not only translate to improved patient outcomes and survivorship, but also reduced healthcare cost and socio-economic burden. To date, there is insufficient evidence from the literature to suggest whether dementia is the cause or effect for fragility fractures, or if indeed there is a bidirectional relationship between the two conditions. Further studies are required to shed light onto this important clinical topic.

Lower pain and higher muscular strength in immigrant women with vitamin D deficiency following vitamin D treatment

BACKGROUND

Vitamin D deficiency is common among immigrants in the Nordic region. It may lead to osteomalacia with severe musculoskeletal pain. There are reports that vitamin D deficiency without osteomalacia may lead to pain but little is known of the effect of treatment.

OBJECTIVE

To investigate whether a moderate dose of cholecalciferol and calcium improves strength and pain in a group of vitamin D deficient women.

DESIGN

Twentyfive immigrant women with vitamin D deficiency diagnosed during pregnancy were treated postpartum with a daily dose of 1,600 IU cholecalciferol and 1,000 mg of calcium. They were examined at the start of treatment and again after 3 months of treatement and the results were statistically compared.

SETTING

Southern parts of Stockholm.

MAIN OUTCOME MEASURES

Serum 25-hydroyvitamin D (25(OH)D), serum-parathyroid hormone (PTH), pain measured by a visual analogue scale (VAS), musculoskeletal strength by performance on a chair stand test (seconds), and bone tenderness by pressure algometer (kilo-Pascal).

RESULTS

Following the treatment, the 21 women attending had lowered cm in VAS, improved musculoskeletal strength, - and 25(OH)D levels were normalized.

CONCLUSIONS

A moderate dose of vitamin D normalized l vitamin D levels, improved muscular strength and reduced pain in this group of vitamin D deficient immigrant women.

Vitamin D deficiency adversely affects early post-operative functional outcomes after total knee arthroplasty

PURPOSE

Vitamin D has received considerable attention in recent years owing to the increasing evidence of its importance in muscle function and physical performance. The present study attempted to determine whether patients with low serum vitamin D levels had impairment in early functional outcomes following total knee arthroplasty (TKA).

METHODS

This was a prospective cohort study that included 92 patients. Patients were divided into two groups according to their vitamin D levels as assessed at the preoperative visit: (1) vitamin D-deficient group, serum 25-hydroxyvitamin D₃ (25(OH)D) levels <12 ng/mL; (2) vitamin D non-deficient group, serum 25(OH)D levels ≥12 ng/mL. American Knee Society Score (KSS) and four other performance tests including the alternative step test (AST), six-metre walk test (SMT), sit-to-stand test (STS), and timed up and go test (TUGT) were used for assessment of post-operative function. All assessments were performed one day before and three months after TKA.

RESULTS

Of the 92 patients included in the study, 87 patients performed all required assessments. The mean post-operative functional KSS was significantly lesser in the vitamin D-deficient group than in the vitamin D non-deficient group (67.2 vs. 73.4, p = 0.031). The mean values of time taken for post-operative AST (16.6 vs. 14.6 s, p = 0.033) and SMT (8.8 vs. 7.7 s, p = 0.012) were significantly longer in the vitamin D-deficient group than in the vitamin D non-deficient group. Post-operative STS and TUGT demonstrated higher values for mean time taken in the vitamin D-deficient group than in the vitamin D non-deficient group, but these were not statistically significant (13.6 vs. 12.4 s, not significant (n.s.); 12.7 vs. 11.7 s, n.s., respectively).

CONCLUSION

Early post-operative functional outcomes following TKA appear to be adversely affected by vitamin D deficiency.

LEVEL OF EVIDENCE

Prospective cohort study, Level II.

Vitamin D and muscle function

Muscle weakness is a hallmark of severe vitamin D deficiency, but the effect of milder vitamin D deficiency or insufficiency on muscle mass and performance and risk of falling is uncertain. In this presentation, I review the evidence that vitamin D influences muscle mass and performance, balance, and risk of falling in older adults. Special consideration is given to the impact of both the starting 25-hydroxyvitamin D [25(OH)D] level and the dose administered on the clinical response to supplemental vitamin D in older men and women. Based on available evidence, older adults with serum 25(OH)D levels <40nmol/L appear most likely to improve their muscle performance with supplementation. The vitamin D dose range of 800-1000 IU per day has been effective in many studies; lower doses have generally been ineffective and several doses above this range have increased the risk of falls. In conclusion, older adults with serum 25(OH)D levels <40nmol/L are likely to have fewer falls if supplemented with 800-1000 IU per day of vitamin D.

A 2-Year Follow-Up After a 2-Year RCT with Vitamin D and Exercise: Effects on Falls, Injurious Falls and Physical Functioning Among Older Women

Background

Both exercise and vitamin D are recommended means to prevent falls among older adults, but their combined effects on fall-induced injuries are scarcely studied.

Methods

A 2-year follow-up of a previous 2-year randomized controlled trial with vitamin D and exercise (Ex) of 409 older home-dwelling women using a factorial 2 × 2 design (D⁻Ex⁻, D⁺Ex⁻, D⁻Ex⁺, D⁺Ex⁺). Besides monthly fall diaries, femoral neck bone mineral density (fn-BMD), and physical functioning were assessed at 1 and 2 years after the intervention.

Results

After the intervention, S-25OHD concentrations declined to baseline levels in both supplement groups. The groups did not differ for change in fn-BMD or physical functioning, except for leg extensor muscle strength, which remained about 10% greater in the exercise groups compared with the reference group (D⁻Ex⁻). There were no between-group differences in the rate of all falls, but medically attended injurious falls reduced in D⁺Ex⁻ and D⁻Ex⁺ groups compared with D⁻Ex⁻. However, all former treatment groups had less medically attended injured fallers, HRs (95% CI) being 0.62 (0.39–1.00) for D⁺Ex⁻, 0.46 (0.28–0.76) for D⁻Ex⁺, and 0.55 (0.34–0.88) for D⁺Ex⁺, compared with D⁻Ex⁻.

Conclusions

Exercise-induced benefits in physical functioning partly remained 2 years after cessation of supervised training. Although there was no difference in the rate of all falls, former exercise groups continued to have lower rate of medically attended injured fallers compared with referents even 2 years after the intervention. Vitamin D without exercise was associated with less injurious falls with no difference in physical functioning.

Vitamin D: Musculoskeletal health

Perhaps the role of Vitamin D supplementation has been most exhaustively studied in calcium absorption, skeletal wellbeing, muscular potency, balance and risk of falling. Nonetheless, new data has emerged and the recent research on sarcopenia makes the topic increasingly interesting. Given the socioeconomic burden of the musculoskeletal consequences of hypovitaminosis D it is vital to keep abreast with the latest literature in the field. The recommended Vitamin D supplementation dose should suffice to increase the serum 25 hydroxyvitamin D level to 30 ng/mL (75 nmol/L) and this level should be optimally maintained with a maintenance dose, particularly for those diagnosed with osteoporosis.

Vitamin D Supplementation Improves Quality of Life and Physical Performance in Osteoarthritis Patients

(1) Background: Lower levels of serum 25-hydroxyvitamin D (25(OH)D) are common in osteoarthritis (OA) patients. However, the effect of vitamin D supplementation on muscle strength and physical performance remains unclear. This study will investigate the effects of vitamin D₂ supplementation on muscle strength and physical performance in knee OA patients; (2) Methods: One hundred and seventy-five primary knee OA patients with low levels of serum 25(OH)D (<30 ng/mL) received 40,000 IU vitamin D₂ (ergocalciferol) per week for six months. Body composition, muscle strength, physical performance, serum 25(OH)D level, leptin, interlukin-6 (IL-6), parathyroid hormone (PTH), protein carbonyl, and metabolic profile were analyzed; (3) Results: Baseline mean serum 25(OH)D levels in knee OA patients was 20.73 ng/mL. Regarding baseline vitamin D status, 58.90% of patients had vitamin D insufficiency, and 41.10% had vitamin D deficiency. After vitamin D₂ supplementation for six months, mean serum 25(OH)D level was 32.14 ng/mL. For post-supplementation vitamin D status, 57.10% of patients had vitamin D sufficiency and 42.90% had vitamin D insufficiency. From baseline to six months, there was a significant increase in mean serum 25(OH)D level (p < 0.001), while mean LDL cholesterol (p = 0.001), protein carbonyl (p = 0.04), and PTH (p = 0.005) all significantly decreased. Patient quality of life (SF-12) and pain (visual analog scale, VAS) both improved significantly from baseline to the six-month time point (p = 0.005 and p = 0.002, respectively). Knee OA patients demonstrated significant improvement grip strength and physical performance measurements after vitamin D₂ supplementation (p < 0.05); (4) Conclusions: Vitamin D₂ supplementation for six months reduced oxidative protein damage, decreased pain (VAS), improved quality of life, and improved grip strength and physical performance in osteoarthritis patients.

High Prevalence of Vitamin D Deficiency in Patients With Bone Marrow Edema Syndrome of the Foot and Ankle

BACKGROUND

Bone marrow edema syndrome (BMOS) is a phenomenon primarily affecting the lower extremity. It is characterized by a sudden onset of pain and an ill-defined osseous hyperintense signal in magnetic resonance imaging. The main cause of BMOS is still largely unknown. Its pathophysiology is presumably multifactorial and it has recently been demonstrated that it usually involves an increase in bone turnover and alterations within the bone microenvironment. Vitamin D plays a pivotal role in maintaining a healthy and well-balanced bone microenvironment. However, to date only limited information has been reported on vitamin D status in patients with BMOS. Moreover, it is still uncertain whether hypovitaminosis D is associated with the etiology and course of the disease. For this reason, the aim of this study was to determine serum vitamin D levels (25(OH)D) of patients diagnosed with BMOS of the foot and ankle.

METHODS

Patients were identified and laboratory results collected by retrospective review of the medical records between year 2011 and 2015. Diagnosis was based on clinical examination, the existence of prolonged foot pain, the presence of abnormal bone marrow signal intensity in T1- and T2-weighted magnetic resonance imaging, and the patient's medical history. All patients who demonstrated other concomitant diagnoses were excluded from the study.

RESULTS

Overall, 31 patients were affected by BMOS with a mean age of 44.4 (range, 18-76) years. Notably, 84% of patients (26/31) had low vitamin D levels with a mean 25(OH)D level of 19.03 ng/mL. Specifically, 61% of patients (19/31) were vitamin D deficient, 23% (7/31) vitamin D insufficient, and only 5 patients (16%) had sufficient vitamin D levels. Statistical analysis showed no significant difference comparing vitamin D levels with patient age, sex, and time of diagnosis. Moreover, there was no correlation between vitamin D status and the number of bony foci or location of BMOS.

CONCLUSION

We found a widespread rate of vitamin D deficiency in patients presenting with BMOS of the foot and ankle. Comparing these data to the vitamin D status of the general population in Germany and to patients living in comparable latitudes, this raises the possibility that BMOS might be associated with low vitamin D status.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The effect of high-dose vitamin D supplementation on muscular function and quality of life in postmenopausal women-A randomized controlled trial

OBJECTIVE

Observational studies have suggested positive associations between serum 25-hydroxyvitamin D (25(OH)D) levels and muscular strength, balance and quality of life. Our aim was to examine whether high-dose vitamin D supplementation would improve these measures as compared to standard-dose vitamin D, as well as the possible muscular effects of single nucleotide polymorphisms (SNPs) in genes encoding vitamin D-related enzymes.

DESIGN

A 12-month randomized, double-blind, controlled trial where the participants received daily elemental calcium (1000 mg) plus vitamin D₃ (800 IU). In addition, the participants were randomized to receive either capsules with vitamin D₃ (20 000 IU) or matching placebos to be taken twice a week.

PATIENTS

A total of 297 postmenopausal women with osteopenia or osteoporosis.

MEASUREMENTS

Muscle strength (handgrip and knee extensor strength), balance (tandem test) and quality of life (EQ-5D) were measured at baseline and after 12 months. The subjects were genotyped for SNPs related to vitamin D metabolism.

RESULTS

Of the 297 included women, 275 completed the study. Mean serum 25(OH)D levels dramatically increased in the high-dose group (from 64.7 to 164.1 nmol/L; P<.01), while a more moderate increased was observed in the standard-dose group (from 64.1 to 81.8 nmol/L; P<.01). There was no significant difference between the groups in change in muscular strength, balance or quality of life over the intervention period. Polymorphisms in rs3829251 (located in the 7-dehydrocholesterol reductase gene) were associated with muscle strength and treatment effects.

CONCLUSION

One-year treatment with high-dose vitamin D had no effect on muscular strength, balance or quality of life in postmenopausal women with osteopenia or osteoporosis as compared to standard dose. The association between rs3829251 and muscle strength needs confirmation in other populations.

Potential role for the VDR agonist elocalcitol in metabolic control: Evidences in human skeletal muscle cells

Vitamin D plays a pivotal role to maintain skeletal muscle integrity and health. Vitamin D deficiency characterizes inflammatory myopathy (IM) and diabetes, often overlapping diseases involving skeletal muscle damage. Vitamin D receptor (VDR) agonists likely exert beneficial effects in both IM and metabolic disturbances. We aim to evaluate in vitro the effect of elocalcitol, a non-hypercalcemic VDR agonist, on the biomolecular metabolic machinery of human skeletal muscle cells (Hfsmc), vs. insulin (I). We analyzed GLUT4, Flotillin-1, Caveolin-3 and Caveolin-1 cell expression/localization; mTOR, AKT, ERK and 4E-BP1 phosphorylation; IL-6 myokine release; VDR expression. We investigated in vivo vitamin D status in IM subjects, evaluating VDR muscular expression and serum vitamin D with metabolism-related parameters, as glycemia, triglycerides, cholesterol, resistin and adiponectin. In Hfsmc, elocalcitol exerted an I-like effect, promoting GLUT4 re-localization in Flotillin-1, Caveolin-3 and Caveolin-1 positive sites and mTOR, AKT, ERK, 4E-BP1 activation; it enhanced IL-6 myokine release. IM subjects, all normoglycemic, showed VDR/vitamin D deficiency that, together with high lipidemic and resistin profile, possibly increases the risk to develop metabolic diseases. VDR agonists as elocalcitol may be therapeutic tools for skeletal muscle integrity/function maintenance, an indispensable condition for health homeostasis.

Effectiveness of Calcifediol in Improving Muscle Function in Post-Menopausal Women: A Prospective Cohort Study

INTRODUCTION

The role of vitamin D supplementation on muscle function and physical performance is still debated. Calcifediol is an available treatment for hypovitaminosis D, particularly for extra-skeletal effects. Aim of this prospective cohort study was to evaluate the effectiveness of calcifediol on serum levels of 25(OH)D3, appendicular muscle strength, physical performance, and prevention of falls in post-menopausal women.

METHODS

We recruited post-menopausal women aged ≥50 years, referring to an outpatient service for the management of osteoporosis over a 18-month period. We included women with a diagnosis of osteoporosis and/or vitamin D deficiency [serum levels of 25(OH)D3 <30 ng/ml]. All the participants received calcifediol (20 μg, 4 oral drops/day) for a 6-month period. We evaluated at the baseline and after 6 months the following outcomes: serum levels of 25(OH)D3, appendicular muscle strength, using the Isometric Hand Grip Strength Test and the Knee Isometric Extension Strength Test, physical performance, using the Short Physical Performance Battery (SPPB) and the 4-m gait speed (4MGS), and the risk of falls (percentage of fallers and recurrent fallers and mean number of falls). A sub-analysis was performed in patients with vitamin D deficiency.

RESULTS

We enrolled 113 post-menopausal women, mean aged 68.01 ± 9.13 years. After 6 months of treatment, there was a significant increase in serum levels of 25(OH)D3 (p < 0.001), appendicular muscle strength (p < 0.001), and physical performance (p = 0.002 at SPPB and p = 0.010 at 4MGS, respectively). At 6 months, the percentage of fallers was lower, although not significantly (p = 0.078), whereas there was a significant reduction both in percentage of recurrent fallers and in the mean number of falls (p < 0.001 and p = 0.020, respectively).

CONCLUSION

Calcifediol was significantly effective in improving serum levels of 25(OH)D3 and muscle function and in reducing the percentage of recurrent fallers and the mean number of falls in a cohort of post-menopausal women.

Is Vitamin D Deficiency Associated With Heart Failure? A Review of Current Evidence

An estimated 1 billion people worldwide have deficient or insufficient levels of vitamin D. Even more alarming is the association of vitamin D deficiency with many types of diseases, particularly heart failure (HF). Hypovitaminosis D has been observed to be highly prevalent in the HF community with rates varying from approximately 80% to 95%. Higher rates of deficiency have been linked to winter months, in patients with protracted decompensated HF, darker skin pigmentation, and higher New York Heart Association (NYHA) classes. In fact, some data suggest vitamin D deficiency may even be an independent predictor of mortality in patients with HF. Traditionally obtained through UV exposure and activated in the liver and then the kidneys, vitamin D is classified as a vitamin but functions as a steroid hormone. The hormone acts through the vitamin D receptor (VDR), which is expressed in vascular smooth muscle cells, renal juxtaglomerular cells, and most interestingly, cardiac myocytes. Studies have shown that the association between vitamin D deficiency and HF often manifests in the structural components of cardiac myocytes and/or through alterations of the neurohormonal cascade. In addition, vitamin D may also act rapidly through intracellular nongenomic receptors that alter cardiac contractility. Unfortunately, prospective vitamin D supplementation trials show mixed results. In rat models, successful correction of deficiency was associated with reductions in ventricular hypertrophy. In humans, however, echocardiographic dimensions did not change significantly. These results bring into questions whether vitamin D is a risk factor for HF, a marker of HF disease severity, or has a true pathologic role. This article provides a thorough review of vitamin D deficiency etiology, prevalence, and possible pathophysiologic role in HF. Furthermore, we carefully review prospective trials on vitamin D therapy in HF. We believe more trials on vitamin D therapy in HF need to be conducted before any conclusions can be drawn.

Long-term adherence and effects on grip strength and upper leg performance of prescribed supplemental vitamin D in pregnant and recently pregnant women of Somali and Swedish birth with 25-hydroxyvitamin D deficiency: a before-and-after treatment study

Background

Muscular weakness and severe vitamin D deficiency is prevalent in Somali (veiled) pregnant women, Sweden. The study aims here were to explore adherence to prescribed supplemental vitamin D in new mothers with vitamin D deficiency and its effects on grip strength and upper leg performance in Somali (target group TG) and Swedish women (reference group RG) from spring through winter.

Methods

A before- and after study was designed. A cross-sectional sample of women in antenatal care with serum 25-OHD ≤50 nmol/L were prescribed one or two tablets daily (800 or 1600 IU vitamin D3 with calcium) for 10 months. Reminders were made by Somali nurses (TG) or Swedish doctors (RG). Baseline and 10 month measurements of plasma nmol/L 25-OHD, maximal grip strength held for 10 s (Newton, N) and ability to squat (yes;no) were done. Total tablet intake (n) was calculated. Outcome variables were changes from baseline in grip strength and ability to squat. Predicting variables for change in grip strength and ability to squat were calculated using linear and binary regression in final models. Undetectable 25-OHD values (<10 nmol/L) were replaced with ‘9’ in statistic calculations.

Results

Seventy-one women (46 TG, 1/3 with undetectable baseline 25-OHD; 25 RG) participated. At the 10-month follow up, 17% TG and 8% RG women reported having refrained from supplement. Mean 25-OHD increased 16 to 49 nmol/L (TG) and 39 nmol/L to 67 nmol/L (RG), (both p < 0.001). Grip strength had improved from 153 to 188 N (TG) (p < 0.001) and from 257 to 297 N (RG) (p = 0.003) and inability to squat had decreased in TG (35 to 9, p < 0.001). Intake of number of tablets predicted increased grip strength (B 0.067, 95%CI 0.008–0.127, p = 0.027). One tablet daily (>300 in total) predicted improved ability to squat (OR 16; 95% CI 1.8–144.6).

Conclusions

Adherence to supplemental vitamin D and calcium should be encouraged as an even moderate intake was associated to improved grip strength and upper leg performance, which was particularly useful for the women with severe 25-OHD deficiency and poor physical performance at baseline.

Trial registration

ClinicalTrials.gov Identifier: NCT02922803. Date of registration: September 28, 2016.

Effects of Vitamin D supplementation on physical activity of patients with Heart Failure

OBJECTIVE

To see the role of Vitamin D supplementation on physical status of patients suffering from Congestive Heart Failure (dilated cardiomyopathy).

METHODS

In this nonrandomized clinical trial, Forty three Patients with dilated cardiomyopathy who were not showing any significant improvements in physical performance on optimal treatment of heart failure were included. Vitamin D (200,000 IU) supplementation on weekly basis for a period of 12 weeks was added to heart failure treatment. And its effect was seen on 6 minutes' walk distance and Pro-BNP levels. SPSS version 19 was used for data analysis. Dependent sample t-test was used to see the significant effect of vitamin D supplementation on pre- intervention vitamin D levels, 6MWD and Pro-BNP. Taking p-value <0.05 as significant.

RESULTS

On clinical assessment most of the patients were in NYHA class II (65%), the percentages of NYHA Class I, III and IV was 19%, 9% and 7% respectively. The baseline mean vitamin D level of the study group was 16.59±3.54ng/ml and it raised to 31.97±3.64ng/ml after 12 weeks of supplementation with vitamin D, p value<0.0005. The mean distance travelled by the study group before the intervention was 806±380ft while it increased to 945±393ft after the intervention, p value of 0.008. The mean of pro-BNP level of the study group before the intervention was 1024±635 while it improved to 159±80 after the intervention with a significant p value<0.0005.

CONCLUSION

Vitamin D supplementation decreases the severity of HF as reflected by reduction in serum pro-BNP levels and significant increase in six minutes' walk distance.

Vitamin D and/or calcium deficient diets may differentially affect muscle fiber neuromuscular junction innervation

INTRODUCTION

There is evidence that supports a role for Vitamin D (Vit. D) in muscle. The exact mechanism by which Vit. D deficiency impairs muscle strength and function is not clear.

METHODS

Three-week-old mice were fed diets with varied combinations of Vit. D and Ca²⁺ deficiency. Behavioral testing, genomic and protein analysis, and muscle histology were performed with a focus on neuromuscular junction (NMJ) -related genes.

RESULTS

Vit. D and Ca²⁺ deficient mice performed more poorly on given behavioral tasks than animals with Vit. D deficiency alone. Genomic and protein analysis of the soleus and tibialis anterior muscles revealed changes in several Vit. D metabolic, NMJ-related, and protein chaperoning and refolding genes.

CONCLUSIONS

These data suggest that detrimental effects of a Vit. D deficient or a Vit. D and Ca²⁺ deficient diet may be a result of differential alterations in the structure and function of the NMJ and a lack of a sustained stress response in muscles. Muscle Nerve 54: 1120-1132, 2016.

Phase IV randomized preference study in patients eligible for calcium and vitamin D supplementation

INTRODUCTION/OBJECTIVES

Preference for supplement formulation helps determine an individual's adherence to long-term medication and can improve clinical benefit for chronic illnesses such as osteoporosis. This study compared the preference, acceptability and tolerability of a reformulation of Calcichew D3 ¹ 500 mg/400 IU and Calcichew D3 500 mg/800 IU (Takeda UK Ltd, Wobrun Green, UK) with Adcal-D3 ² 500 mg/400 IU (ProStrakan Ltd, Galashiels, UK) and Kalcipos-D 500 mg/800 IU (Meda Pharmaceuticals Ltd, Bishop's Stortford, UK), respectively.

METHOD

This phase IV, randomized, open-label, two-period, cross-over study was conducted at nine sites in the UK and Germany. Eligible subjects (≥65 years requiring calcium/vitamin D supplementation for prevention/treatment of deficiencies, or ≥18 years requiring supplementation as an adjunct to osteoporosis treatment) were randomly assigned to one of two 2 week treatment sequences - Group 1: Calcichew D3 500/400 then Adcal-D3 500/400 (or vice versa), or Group 2: Calcichew D3 500/800 then Kalcipos-D 500/800 (or vice versa). After each treatment period, patients rated the treatment for acceptability using 100 mm visual analogue scales. After the second treatment period, patients indicated their treatment preference. The primary endpoint, the percentage of patients with a preference for each treatment, was analyzed with a logistic regression model.

RESULTS

Two hundred and seventy-six patients were randomly assigned by treatment sequence, 138 to each group. Preference questionnaires among patients who preferred Calcichew or comparator revealed the odds for patients preferring Calcichew 500/400 (77.6%) over Adcal-D3 was 3.46 ([95% CI 2.24, 5.36], p < 0.001) in Group 1, and Calcichew D3 500/800 (63.2%) over Kalcipos-D was 1.72 ([1.19, 2.47], p = 0.004) in Group 2. Adverse events were mostly gastrointestinal and were comparable between groups. The new formulation of Calcichew D3 is acceptable and consistent with its known tolerability profile.

CONCLUSIONS

In this short-term 30 day study, patients preferred Calcichew D3 500/400 and Calcichew D3 500/800 over respective comparators. A trend towards better compliance with Calcichew D3 preference observed in Group 1 warrants a longer term study to identify treatment compliance.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02457247.

Vitamin D supplementation and its influence on muscle strength and mobility in community-dwelling older persons: a systematic review and meta-analysis

Background

It has been suggested that vitamin D status or supplementation is important for maintaining or improving muscle strength and mobility in older adults. The study results, however, do not provide consistent results. We therefore aimed to summarise the available evidence systematically, including only studies conducted in community‐dwelling older persons.

Methods

A systematic search of the literature was performed in April of 2016. The systematic review includes studies that used vitamin D with or without calcium supplementation as the exposure variable and various measurements of muscle strength and mobility. The meta‐analysis was limited to studies using hand grip strength (HGS) and timed‐up‐and‐go test as the outcome variables.

Results

A total of 15 studies out of 2408 articles from the literature search were included in the systematic review, providing 2866 participants above the age of 65 years. In the majority of studies, no improvement in muscle strength and mobility was observed after administration of vitamin D with or without calcium supplements. In the meta‐analysis, we observed a nonsignificant change in HGS [+0.2 kg (95% confidence interval = −0.25 to 0.7 kg; seven studies)] and a small, significant increase in the timed‐up‐and‐go test [0.3 s (95% confidence interval = 0.1 to 0.5 s; five studies)] after vitamin D supplementation. The meta‐analyses showed a high degree of heterogeneity between the studies.

Conclusions

In conclusion, we observed no improvement in muscle strength after the administration of vitamin D with or without calcium supplements. We did find a small but significant deterioration of mobility. However, this is based on a limited number of studies and participants.

Calcium intake: good for the bones but bad for the heart? An analysis of clinical studies

The proper dietary calcium intake and calcium supplementation, when indicated, are important factors in the acquisition of peak bone mass during youth and in the prevention of fractures in old age. In addition to its deposition in bone, calcium confers an increase in its resistance and exhibits important activities in different enzymatic pathways in the body (e.g., neural, hormonal, muscle-related and blood clotting pathways). Thus, calcium supplementation can directly or indirectly affect important functions in the body, such as the control of blood pressure, plasma glucose, body weight, lipid profile and endothelial function. Since one publication reported increased cardiovascular risk due to calcium supplementation, many researchers have studied whether this risk actually exists; the results are conflicting, and the involved mechanisms are uncertain. However, studies that have evaluated the influence of the consumption of foods rich in calcium have reported no increase in the cardiovascular risk, which suggests that nutritional intake should be prioritized as a method for supplementation and that the use of calcium supplements should be reserved for patients who truly need supplementation and are unable to achieve the recommended daily nutritional intake of calcium.

Relation among 25(OH)D, Aquatic Exercises, and Multifunctional Fitness on Functional Performance of Elderly Women from the Community

OBJECTIVES

The aim of this study was to investigate if there is a relation among 25(OH)D, aquatic training, and multifunctional fitness on functional performance of elderly woman from the community.

DESIGN

Cross-sectional study.

SETTING

Community.

PARTICIPANTS

We evaluated elderly women aged ≥ 60 years (67±5 years old). One-hundred eighty were engaged in aquatic training (AT), 119 in multifunctional fitness (MF) for at least one year, and sedentary group (SED) with 162 independent elderly women from the community centers who had not practicing any regular physical exercise at least one year before.

MEASUREMENTS

Timed up-and-go (TUG), 2-minute step test (2MST), 30-second chair stand (CS), arm curl (AC), functional reach test (FRT), unipedal balance test (UB) with visual control, handgrip right (HR) and handgrip left (HL) portable dynamometer for strength hip flexors (Hip strength) and knee extensors (Knee strength), serum 25(OH)D, intact parathyroid hormone (PTH), and creatinine clearance.

RESULTS

Physical and functional tests showed differences among the three groups (ST; TUG, CS, AC, FR and USB = p <0.001). The PTH and the TUG test correlated inversely with 25(OH)D (r = -0.29 - p <0.001/ r = - 0.16 - p <0.001), also between 25(OH)D and BMI for AT and MF groups respectively (r= -0,15; p=0,04/ r= - 0,19; p=0,036). The AC test showed positive correlation (r = 0, 1 - p <0.001). The age and 25(OH)D were controlled and assumed to be a covariates in the statistical analysis that employed ANCOVA. There was difference on the performance of TUG test (p= 0.049).

CONCLUSION

TUG performance was associated with age, exercise type and serum levels of 25(OH)D. The 25(OH)D insufficiency was common in elderly women from subtropical areas.

Vitamin D3 supplementation using an oral spray solution resolves deficiency but has no effect on VO2 max in Gaelic footballers: results from a randomised, double-blind, placebo-controlled trial

PURPOSE

Vitamin D inadequacy is a global health concern in athletes as well as the general population. Whilst the role of vitamin D in skeletal health is well defined, there remains uncertainty over whether vitamin D supplementation has an added benefit beyond bone health.

METHODS

This randomised placebo-controlled trial in healthy male and female Gaelic footballers (n = 42) investigated the effect of vitamin D₃ supplementation [3000 IU (75 µg) daily for 12 weeks, via an oral spray solution] on VO₂ max which was the primary outcome measure. Secondary outcomes included skeletal muscle and lung function.

RESULTS

Supplementation significantly increased total 25-hydroxyvitamin D concentrations compared to the placebo group (mean ± SD change from baseline, 36.31 ± 32.34 vs. 6.11 ± 23.93 nmol/L, respectively; P = 0.006). At baseline, 50 and 22 % of footballers presented with vitamin D insufficiency (31-49 nmol/L) and deficiency (<30 nmol/L), respectively. Total 25-hydroxyvitamin D concentration did not significantly correlate with any measure of physical performance. Analysis of covariance (ANCOVA) models demonstrated that vitamin D supplementation over 12 weeks had no significant effect on VO₂ max (P = 0.375), vertical jump height (P = 0.797), left and right handgrip strength (P = 0.146 and P = 0.266, respectively), forced vital capacity (P = 0.573) or forced expiratory volume at 1 s (P = 0.665), after adjusting for confounders. The high prevalence of vitamin D inadequacy observed in this cohort of collegiate Gaelic footballers supports the need for vitamin D supplementation during wintertime to avoid being at risk of poor bone health.

CONCLUSIONS

Twelve-week daily supplementation with 3000 IU (75 µg) vitamin D₃ successfully resolved deficiency but did not have any significant effect on VO₂ max, skeletal muscle or lung function.

Vitamin D3 intake modulates diaphragm but not peripheral muscle force in young mice

Recent data support an important role for vitamin D in respiratory health. We tested the hypothesis that dietary vitamin D3 (VD3) intake modulates diaphragm (DIA) strength. Four-week-old female A/J mice (n = 10/group) were randomized to receive diets containing 100 IU VD3/kg (low), 1,000 IU VD3/kg (reference), or 10,000 IU VD3/kg (pharmacologic). After 6 wk of dietary intervention, plasma 25-hydroxyvitamin D3 (25D3) levels, DIA and extensor digitorum longus (EDL) in vitro contractile properties, and fiber cross-sectional area (CSA) were measured. Myosin heavy chain (MHC) composition and Akt/Foxo3A growth signaling were studied in the DIA and tibialis anterior. Mice fed the low, reference, and pharmacologic diets had average 25D3 levels of 7, 21, and 59 ng/ml, respectively. Maximal DIA force, twitch force, and fiber CSA were reduced 26%, 28%, and 10% (P < 0.01), respectively, in mice receiving the low-VD3 diet compared with the reference and pharmacologic diets. EDL force parameters were unaltered by diet. Effects of VD3 intake on DIA force were not observed in mice that began dietary intervention at 12 wk of age. VD3 intake did not alter the MHC composition of the DIA, indicating that decreases in force and CSA in young mice were not due to a switch in fiber type. Paradoxically, low VD3 intake was associated with activation of anabolic signaling in muscle (hyperphosphorylation of Akt and Foxo3A and decreased expression of autophagy marker LC3). These studies identify a potential role of dietary VD3 in regulating DIA development and insulin sensitivity.

Effects of Vitamin D and Exercise on the Wellbeing of Older Community-Dwelling Women: A Randomized Controlled Trial

Background: Evidence for the effects of exercise and vitamin D supplementation on quality of life (QoL), fear of falling (FoF) and mental wellbeing in older adults is conflicting. Objective: To study the effects of vitamin D supplementation and multimodal group exercise on psychosocial functions of wellbeing, including QoL, mental wellbeing and FoF. Method: This is a 2-year, double-blind, placebo-controlled vitamin D and open exercise intervention trial with 409 older Finnish women (70-80 years of age) randomized to 4 treatment arms: (1) placebo without exercise, (2) vitamin D (800 IU/day) without exercise, (3) placebo and exercise, and (4) vitamin D (800 IU/day) with exercise. Exercisers participated in group exercise twice per week for 12 months and once per week for the subsequent 12 months, plus home exercises. Results: When comparing with the placebo without exercise group, there were no statistically significant differences between groups receiving either vitamin D, exercise or both treatments for changes in QoL or mental wellbeing (although a slight decline was seen in mental wellbeing in those receiving vitamin D only, p = 0.044). The initial slight reduction in FoF was significant in all intervention groups compared with controls (p < 0.05), but this was only temporary. Conclusion: Neither vitamin D nor exercise contributes to better QoL, FoF or mental wellbeing in community-dwelling healthy older women with sufficient vitamin D levels.

Vitamin D supplementation to prevent depression and poor physical function in older adults: Study protocol of the D-Vitaal study, a randomized placebo-controlled clinical trial

BACKGROUND

Depressive symptoms and decreased physical functioning are interrelated conditions and common in older persons, causing significant individual and societal burden. Evidence suggests that vitamin D supplementation may be beneficial for both mental and physical functioning. However, previous randomized controlled trials have yielded inconsistent results and often had suboptimal designs. This study examines the effect of vitamin D supplementation on both depressive symptoms and physical functioning in a high-risk population of older persons with low vitamin D status.

METHODS/DESIGN

The D-Vitaal study is a randomized, double-blind, placebo-controlled trial investigating the effects of a daily dose of 1200 IU vitamin D3 versus placebo for one year on depressive symptoms and physical functioning (primary outcomes) in older adults. Participants (N = 155, age 60-80 years) were recruited from the general population. Eligibility criteria included the presence of depressive symptoms, ≥1 functional limitation and serum 25-hydroxyvitamin D levels between 15 and 50/70 nmol/L (depending on season). Secondary outcomes include incidence of major depressive disorder, anxiety symptoms, health-related quality of life, cognitive function and cost-effectiveness of the intervention.

DISCUSSION

With this study, we aim to elucidate the effects of vitamin D supplementation on depressive symptoms and physical functioning in older persons who are at high risk of developing more substantial mental and physical problems. If effective, vitamin D supplementation can be a preventive intervention strategy that is easy to implement in the primary care setting.

TRIAL REGISTRATION

Netherlands Trial Register NTR3845. Registered 6 February 2013.

The "Dose-Effect" Relationship Between 25-Hydroxyvitamin D and Muscle Strength in Hemodialysis Patients Favors a Normal Threshold of 30 ng/mL for Plasma 25-Hydroxyvitamin D

OBJECTIVE

Muscle strength is weakened in maintenance hemodialysis patients. Strength is both a measure of a functional parameter and of frailty as it is independently associated with mortality. In the general population, observational studies show that plasma 25-hydroxyvitamin D (25[OH]D) is positively correlated with muscle strength and function. We analyzed the determinants of muscle strength measured by handgrip and 25(OH)D in a maintenance hemodialysis population.

METHODS

In this observational cross-sectional study, data from all hemodialysis patients from our nephrology department were recorded in July 2014. Daily nutritional oral intake, handgrip strength, body composition measured by bioimpedancemetry analysis, as well as biological and dialysis parameters, were obtained from medical files. We used a linear regression model to assess nutritional, biological, and dialysis parameters as well as body composition associated with handgrip strength.

RESULTS

The median age (interquartile range) of the 130 included patients was 77.3 (69.5-84.7) years, 57.7% were men, and 50.8% had diabetes mellitus. Median handgrip strength value (interquartile range) was 14.3 (10.6-22.2) kg. In univariate analyses, the factors associated with handgrip strength were age, gender, albumin, transthyretin, predialysis creatinine and urea, normalized protein nitrogen appearance, lean mass, and muscle mass measured by bioimpedancemetry analysis as well as phase angle, and 25(OH)D. In multivariate analyses, lower age, male gender, higher albumin, higher muscle mass, and 25(OH)D level ≥ 30 ng/mL were independently correlated with muscle strength measured by handgrip.

CONCLUSIONS

This study found a positive correlation between plasma 25(OH)D and muscle strength measured by handgrip in hemodialysis patients. We report a "dose-effect" relationship between 25(OH)D and handgrip strength under 30 ng/mL, which is no more present above 30 ng/mL. Prospective randomized studies are needed to prove that supplementation with cholecalciferol, leading to 25(OH)D levels ≥ 30 ng/mL, improves muscle strength in hemodialysis patients.

Should we prescribe calcium or vitamin D supplements to treat or prevent osteoporosis?

Systematic reviews of randomized, controlled trials (RCTs) are considered the highest level of evidence to inform clinical practice. Meta-analyses of large RCTs of calcium and/or vitamin D supplements completed in the last 15 years provide strong evidence for clinical recommendations. These meta-analyses with data for > 50,000 older adults reported that calcium with or without vitamin D has only weak, inconsistent effects on fracture, and that vitamin D without calcium has no effect on fracture. Only one RCT of co-administered calcium and vitamin D in frail, institutionalized, elderly women with low dietary calcium intake and vitamin D levels showed significant reductions in fracture risk. These RCTs have also reported previously unrecognized adverse events of calcium supplements including kidney stones, myocardial infarction, hypercalcemia, and hospitalization with acute gastrointestinal symptoms. The small risk of these important adverse effects, together with the moderate risk of minor side-effects such as constipation, probably outweighs any benefits of calcium supplements on fracture. These data suggest the role for calcium and vitamin D supplements in osteoporosis management is very limited. Neither calcium nor vitamin D supplements should be recommended for fracture prevention in community-dwelling adults, although vitamin D should be considered for prevention of osteomalacia in at-risk individuals.

Hypovitaminosis D is associated with a reduction in upper and lower limb muscle strength and physical performance in post-menopausal women: a retrospective study

BACKGROUND

Elderly people experience a gradual loss of muscle strength and a reduction of serum levels of vitamin D and of vitamin D receptor expression in skeletal muscle cells.

AIMS

The aim of our study was to evaluate the association among serum levels of 25-hydroxy-vitamin D [25(OH)D3], muscle strength, and physical performance in post-menopausal women.

METHODS

In our retrospective case-control study, we analyzed data from medical records of post-menopausal women aged ≥ 50 years. We compared subjects with hypovitaminosis D [25(OH)D3 <30 ng/ml] vs. those with normal levels [25(OH)D3 ≥ 30 ng/ml]. Outcome measures were: Hand Grip Strength Test (HGS) and Knee Extension Strength Test (KES) to evaluate upper and lower limb muscle strength, respectively; Short Physical Performance Battery (SPPB) and usual 4-m gait speed (4 MGS) to evaluate physical performance.

RESULTS

We examined 80 patients (mean aged 65.92 ± 7.69 years): forty-six subjects with hypovitaminosis D (mean aged 66.09 ± 7.71 years) and 34 with normal levels of vitamin D (mean aged 65.71 ± 7.78 years). There was a statistically significant difference between hypovitaminosis D group and subjects with normal levels of vitamin D in HGS (12.13 ± 4.34 vs. 19.14 ± 5.59; p < 0.001), KES (11.99 ± 4.04 vs. 16.98 ± 8.43; p = 0.003), SPPB score [8 (5.75-10.25) vs. 12 (10-12); p < 0.001], and proportion of patients with usual 4 MGS ≤ 0.8 m/s [29 (63.0%) vs. 9 (26.5%); p = 0.002].

DISCUSSION

In literature, there is no agreement on the association among serum vitamin D levels and muscle function. Our data showed that post-menopausal women with hypovitaminosis D had worse upper and lower limb muscle strength and physical performance than subjects with normal levels of 25(OH)D3.

CONCLUSIONS

Our results support the hypothesis that there is a significant positive association among serum 25(OH)D3 levels and upper and lower limb muscle functioning.

Effect of vitamin D supplementation alone on muscle function in postmenopausal women: a randomized, double-blind, placebo-controlled clinical trial

The present study investigates the effects of vitamin D on muscle function in postmenopausal women. It has been shown that vitamin D supplementation in postmenopausal women with hypovitaminosis D provides significant protective factor against sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass.

INTRODUCTION

We aimed to evaluate the effect of supplementation of vitamin D (VITD) alone on muscle function in younger postmenopausal women.

METHODS

In this double-blind, placebo-controlled clinical trial, 160 Brazilian postmenopausal women were randomized into two groups: VITD group consisting of patients receiving vitamin D3 1000 IU/day orally (n = 80) or placebo group (n = 80). Women with amenorrhea for more than 12 months and age 50-65 years, with a history of falls (previous 12 months), were included. The intervention time was 9 months, with assessments at two points, start and end. Lean mass was estimated by total-body dual-energy X-ray absorptiometry (DXA) and muscle strength by handgrip strength and chair rising test. The plasma concentrations of 25-hydroxyvitamin D [25(OH)D] were measured by high-performance liquid chromatography (HPLC). Statistical analysis was by intention to treat (ITT), using ANOVA, Student's t test, and Tukey's test.

RESULTS

After 9 months, average values of 25(OH)D increased from 15.0 ± 7.5 to 27.5 ± 10.4 ng/ml (+45.4%) in the VITD group and decreased from 16.9 ± 6.7 to 13.8 ± 6.0 ng/ml (-18.5%) in the placebo group (p < 0.001). In the VITD group, there was significant increase in muscle strength (+25.3%) of the lower limbs by chair rising test (p = 0.036). In women in the placebo group, there was considerable loss (-6.8%) in the lean mass (p = 0.030).

CONCLUSION

The supplementation of vitamin D alone in postmenopausal women provided significant protective factor against the occurrence of sarcopenia, with significant increases in muscle strength and control of progressive loss of lean mass.

Does vitamin-D intake during resistance training improve the skeletal muscle hypertrophic and strength response in young and elderly men? - a randomized controlled trial

Introduction

Recent studies have shown that vitamin-D intake can improve skeletal muscle function and strength in frail vitamin-D insufficient individuals. We investigated whether vitamin-D intake can improve the muscular response to resistance training in healthy young and elderly individuals, respectively.

Methods

Healthy untrained young (n = 20, age 20–30) and elderly (n = 20, age 60–75) men were randomized to 16 weeks of daily supplementary intake of either 48 μg of vitamin-D + 800 mg calcium (Vitamin-D-group) or 800 mg calcium (Placebo-group) during a period and at a latitude of low sunlight (December-April, 56°N). During the last 12 weeks of the supplementation the subjects underwent progressive resistance training of the quadriceps muscle. Muscle hypertrophy, measured as changes in cross sectional area (CSA), and isometric strength of the quadriceps were determined. Muscle biopsies were analyzed for fiber type morphology changes and mRNA expression of vitamin-D receptor (VDR), cytochrome p450 27B1 (CYP27B1) and Myostatin.

Results

In the vitamin-D groups, serum 25(OH)D concentration increased significantly and at week 12 was significantly different from placebo in both young men (71.6 vs. 50.4 nmol/L, respectively) and elderly men (111.2 vs. 66.7 nmol/L, respectively). After 12 weeks of resistance training, quadriceps CSA and isometric strength increased compared to baseline in young (CSA p < 0.0001, strength p = 0.005) and elderly (CSA p = 0.001, strength p < 0.0001) with no difference between vitamin-D and placebo groups. Vitamin-D intake and resistance training increased strength/CSA in elderly compared to young (p = 0.008). In the young vitamin-D group, the change in fiber type IIa percentage was greater after 12 weeks training (p = 0.030) and Myostatin mRNA expression lower compared to the placebo group (p = 0.006). Neither resistance training nor vitamin-D intake changed VDR mRNA expression.

Conclusion

No additive effect of vitamin-D intake during 12 weeks of resistance training could be detected on either whole muscle hypertrophy or muscle strength, but improved muscle quality in elderly and fiber type morphology in young were observed, indicating an effect of vitamin-D on skeletal muscle remodeling.

Trial registration

ClinicalTrials with nr. NCT01252381

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-015-0029-y) contains supplementary material, which is available to authorized users.

Vitamin D supplementation and quality of life following diagnosis in stage II colorectal cancer patients: a 24-month prospective study

PURPOSE

Research suggests patients are motivated to supplement standard cancer care with healthy lifestyle changes. However, few studies have prospectively investigated whether these changes result in positive outcomes. In this study, our objective was to examine the associations between vitamin D supplementation and quality of life (QoL), cancer recurrence, and all-cause mortality in stage II CRC patients following diagnosis.

METHODS

A total of 453 newly diagnosed patients were enrolled from the North Carolina Central Cancer Registry. Data on demographic variables, treatment, and health behaviors were collected by interview at diagnosis, 12, and 24 months post-diagnosis. QoL was measured using the FACT-C and SF-12 questionnaires.

RESULTS

After adjustment for potential confounders, the survivors who used vitamin D supplements had a better CCS score (subscale of FACT-C) over 24 months compared to non-users (β = 1.28; 95 % CI 0.07-2.48). This association persisted among calcium users (β = 2.41; 95 % CI 1.01-3.82), but not in non-users (β = 0.34; 95 % CI -1.45-2.13) (P interaction = 0.09). No association was observed with risk of recurrence or mortality.

CONCLUSIONS

This suggests that vitamin D supplementation may jointly influence QoL with calcium following diagnosis in CRC survivors. These results also support the notion that clinicians should recommend positive lifestyle changes in conjunction with the standard of care.

Association of Hyponatremia and Hypovitaminosis D in Ambulatory Adults

Background

Hyponatremia and vitamin D deficiency are frequent disorders, and both have been associated with gait disturbances, falls and fractures. The aim of this study was to evaluate the existence of an association between serum sodium and vitamin D serum levels.

Methods

We performed a retrospective investigation to establish whether hyponatremia and vitamin D deficiency may be associated in a general population of unselected outpatients. An electronic search was performed in the laboratory information systems of the Hospital of Verona and the Hospital of Parma (Italy), to retrieve combined results for total vitamin D and sodium obtained in all outpatients referred for health check-up in the year 2013.

Results

Combined results of vitamin D and sodium could be retrieved for 5097 outpatients (3859 females and 1238 males; mean age 64±17 years). Vitamin D deficient subjects displayed significantly lower levels of serum sodium (140 versus 141 mmol/L; p<0.001), along with a significantly higher rate of hyponatremia (6.3% versus 5.1%; p=0.037). Accordingly, hyponatremic subjects had significantly lower levels of serum vitamin D (55 versus 60 nmol/L; p=0.015), along with a significantly higher rate of vitamin D deficiency (41.8% versus 36.1%; p=0.030). A highly significant correlation was found between sodium and total vitamin D after adjustment for age and gender (p<0.001).

Conclusions

The results of this study demonstrate for the first time the existence of a significant correlation between the serum levels of sodium and total vitamin D in a general population of unselected outpatients.

Determinants of parathyroid hormone response to vitamin D supplementation: a systematic review and meta-analysis of randomised controlled trials

This systematic review aimed to assess the determinants of the parathyroid hormone (PTH) level response to vitamin D supplementation. We searched Medline, Google Scholar and the reference lists of previous reviews. All randomised controlled trials (RCT) on vitamin D supplementation that involved apparently healthy human subjects with a report of PTH were selected. Potential studies were screened independently and in duplicate. Results are summarised as mean differences with 95% confidence intervals. Quality assessment, subgroup analysis, meta-analysis and meta-regression analysis were carried out. Thirty-three vitamin D supplementation RCT were included. Vitamin D supplementation significantly raised circulating 25-hydroxyvitamin D (25(OH)D) with significant heterogeneity among studies with a pooled mean difference (PMD) of 15.5 ng/ml (test for heterogeneity: P<0·001 and I 2=97·3%). Vitamin D supplementation significantly reduced PTH level with PMD of -8·0 pg/ml, with significant heterogeneity ((test for heterogeneity: P<0·001) and the I 2 value was 97·3%). In the subgroup analyses, the optimum treatment effect for PTH was observed with Ca doses of 600-1200 mg/d (-22·48 pg/ml), after the duration of a >12-month trial (-18·36 pg/ml), with low baseline 25(OH)D concentration of <20 ng/ml (-16·70 pg/ml) and in those who were overweight and obese (-18·11 pg/ml). Despite the present meta-analysis being hindered by some limitations, it provided some interesting evidence, suggesting that suppression of PTH level needs higher vitamin D intake (75 μg/d) than the current recommendations and longer durations (12 months), which should be taken into account for nutritional recommendations.