Peak expiratory flow rate shows a gender-specific association with vitamin D deficiency

Long-term trajectories of peak expiratory flow rate in older men and women show linear decline mainly determined by baseline levels

BACKGROUND

Peak expiratory flow rate (PEFR) predicts mortality and other negative health outcomes. However, little evidence exists on how PEFR changes with ageing and how trajectories of change differ among older people.

AIMS

To identify trajectories of PEFR in older men and women, and to study characteristics associated with these trajectories.

METHODS

Data from the Longitudinal Aging Study Amsterdam were used, an ongoing cohort study in a representative sample of Dutch older men and women. PEFR was assessed using the Mini-Wright peak flow meter across a 13-year follow-up in 991 men and 1107 women. Trajectories were analyzed using Latent Class Growth Analysis.

RESULTS

Mean age was 72.5 (SD 8.4) in men and 72.4 (SD 8.4) in women. In men, three declining trajectories were identified, i.e. high, intermediate and low, with prevalences of 30%, 46% and 24%, respectively. In women, two declining trajectories were identified, i.e. high and low, with prevalences of 62 and 38%. All trajectories showed linear decline and differed mostly with regard to their intercept. Significant differences between trajectories with regard to baseline demographic, health and lifestyle characteristics were observed, e.g., men and women in the low PEFR trajectory were older, had more chronic diseases, and were more often smoker.

DISCUSSION AND CONCLUSIONS

Trajectories in both men and women differ mainly in baseline level of PEFR and not in rate of decline over time. Therefore, one PEFR measurement might be sufficient to give an indication of the trajectory that an older adult is likely to follow.

Negligible effect of vitamin D supplementation on exacerbation in patients with chronic obstructive pulmonary disease: meta-analysis

Introduction

The focus of this meta-analysis was how vitamin D supplementation influences exacerbations in patients with chronic obstructive pulmonary disease (COPD) and vitamin D deficiency (VDD).

Materials and methods

Cochrane Library, Web of Science, Embase, and PubMed databases have been systematically searched in an attempt to collect randomized controlled trials related to vitamin D supplementation in COPD patients with VDD published in English available by July 2022. Primary outcome indicators included the mean number of exacerbation and rate of exacerbation. Secondary outcome indicators included forced expiratory volume in the first second (FEV1), FEV1/forced vital capacity (FVC) ratio, and serum 25-hydroxyvitamin D (25(OH)D) concentration.

Results

Five studies involving 522 COPD patients with VDD (defined as 25(OH)D < 50 nmol/L) were included, among them 61 were severely deficient in vitamin D (25(OH)D < 25 nmol/L). The results showed that vitamin D supplementation did not decrease the mean number of exacerbation (standardized mean difference (SMD): - 0.10, 95% CI: - 0.29 to 0.09) and the rate of exacerbation (relative risk (RR): 0.89, 95% CI: 0.76 to 1.04, P = 0.179). Also, its effect on FEV1 (SMD: - 0.06, 95% CI: - 0.30 to 0.17) and FEV1/FVC (SMD: -0.10, 95% CI: - 0.48 to 0.27) remained negligible. However, it could increase the serum 25(OH)D concentration (SMD: 2.44, 95 CI%: 2.20 to 2.68, P < 0.001).

Conclusions

The effects of vitamin D supplementation on decreasing exacerbation and improving pulmonary function were not significant.

Development and validation of an intrinsic capacity composite score in the Longitudinal Aging Study Amsterdam: a formative approach

BACKGROUND

Intrinsic capacity (IC) defined by the WHO refers to the composite of five domains of capacities. So far, developing and validating a standardized overall score of the concept have been challenging partly because its conceptual framework has been unclear. We consider that a person's IC is determined by its domain-specific indicators suggesting a formative measurement model.

AIMS

To develop an IC score applying a formative approach and assess its validity.

METHODS

The study sample (n = 1908) consisted of 57-88-year-old participants from the Longitudinal Aging Study Amsterdam (LASA). We used logistic regression models to select the indicators to the IC score with 6-year functional decline as an outcome. An IC score (range 0-100) was constructed for each participant. We examined the known-groups' validity of the IC score by comparing groups based on age and number of chronic diseases. The criterion validity of the IC score was assessed with 6-year functional decline and 10-year mortality as outcomes.

RESULTS

The constructed IC score included seven indicators covering all five domains of the construct. The mean IC score was 66.7 (SD 10.3). The scores were higher among younger participants and those who had lower number of chronic diseases. After adjustment for sociodemographic indicators, chronic diseases, and BMI, a one-point higher IC score was associated with a 7% decreased risk for 6-year functional decline and a 2% decreased risk for 10-year mortality.

CONCLUSIONS

The developed IC score demonstrated discriminative ability according to age and health status and is associated with subsequent functional decline and mortality.

Serum vitamin D levels and peak cough flow in patients with subacute ischemic stroke

Aspiration pneumonia is a major, potentially fatal complication after ischemic stroke. Decreased coughing function is a significant risk factor for aspiration in ischemic stroke survivors. Peak cough flow (PCF) is a useful tool for assessing cough function. Vitamin D deficiency is frequent after ischemic stroke and is linked to a variety of muscle functions and physical activities. There has been no investigation of the correlation between vitamin D levels and PCF in ischemic stroke survivors. This study aimed to examine the relationship between serum vitamin D levels and PCF in patients with ischemic stroke. Patients with ischemic stroke who underwent PCF evaluation and serum vitamin D level measurements within 1 month of onset were retrospectively recruited. The association between PCF parameters and serum vitamin D levels was also analyzed. In total, 142 patients with ischemic stroke were included. PCF parameters and serum vitamin D levels were found to be significantly correlated. Moreover, serum vitamin D levels were shown to be a significant predictor of PCF parameters. Serum vitamin D levels were related to PCF parameters in patients with ischemic stroke. In addition, serum vitamin D level may serve as a predictor of coughing function in patients with ischemic stroke.

Vitamin D Impacts on Skeletal Muscle Dysfunction in Patients with COPD Promoting Mitochondrial Health

Skeletal muscle dysfunction is frequently associated with chronic obstructive pulmonary disease (COPD), which is characterized by a permanent airflow limitation, with a worsening respiratory disorder during disease evolution. In COPD, the pathophysiological changes related to the chronic inflammatory state affect oxidant–antioxidant balance, which is one of the main mechanisms accompanying extra-pulmonary comorbidity such as muscle wasting. Muscle impairment is characterized by alterations on muscle fiber architecture, contractile protein integrity, and mitochondrial dysfunction. Exogenous and endogenous sources of reactive oxygen species (ROS) are present in COPD pathology. One of the endogenous sources of ROS is represented by mitochondria. Evidence demonstrated that vitamin D plays a crucial role for the maintenance of skeletal muscle health. Vitamin D deficiency affects oxidative stress and mitochondrial function influencing disease course through an effect on muscle function in COPD patients. This review will focus on vitamin-D-linked mechanisms that could modulate and ameliorate the damage response to free radicals in muscle fibers, evaluating vitamin D supplementation with enough potent effect to contrast mitochondrial impairment, but which avoids potential severe side effects.

Gender-Dependent Association of Vitamin D Deficiency with Obesity and Hypercholesterolemia (LDLC) in Adults

BACKGROUND

Obesity, dyslipidemia and vitamin D deficiency are growing health problems in the Arabian Gulf region. Their association with each other is yet to be clarified.

METHODS

Three-hundred and fourteen Bahraini adults, 164 males and 150 females comparable in median age (34.5 vs. 31.0 yrs), body mass index (BMI), and ethnicity were recruited. The plasma level of 25-hydroxyvitamin D3 (25OHD3) was measured by chemiluminescent immunoassay and lipid profile parameters were measured by an automated clinical chemistry analyzer. Based on BMI, study subjects were grouped into underweight, normal, overweight, moderate obesity, and severe obesity subjects.

RESULTS

The results revealed an extremely high prevalence of vitamin D deficiency (79.9%) and insufficiency (18.8%). The predictors of low 25OHD3 levels were female gender, small age, conservative dressing, least exposure to sunlight, and less fish intake. In all subjects, the lowest 25OHD3 level was seen in underweight and severe obesity groups. Furthermore, the 25OHD3 level was significantly higher in males as compared to females and it was positively correlated with the age. However, detailed analysis showed that overweight males unlike females had the highest 25OHD3 levels which were significantly higher than in the severely obese males. While the lipid profile parameters were positively correlated with BMI, the total and LDL cholesterols were negatively correlated with the levels of 25OHD3 in males.

CONCLUSION

Vitamin D deficiency was associated with both severely obese and underweight subjects, in the former it was likely to be institutional while in the latter it was likely to be nutritional. Furthermore, hypercholesterolemia (LDL-C) was associated with 25OHD3 sub-normality. Further analysis revealed that the significant associations were gender-dependent.

Impact of Tongue Pressure and Peak Expiratory Flow Rate on Nutritional Status of Older Residents of Nursing Homes in Japan: A Cross-Sectional Study

OBJECTIVES

Swallowing function is critical for continuing oral feeding to prevent frailty in older adults. In this study, we investigated the impact of tongue pressure and pulmonary function on the nutritional status of older adults.

DESIGN, SETTING, PARTICIPANTS

This cross-sectional study was conducted in Kitakyushu, Japan from August 2017 to November 2018. Fifty-two residents aged >65 years of age from three nursing care insurance facilities in Kitakyushu City, Japan were recruited.

MEASUREMENTS

Oral health status, swallowing function, nutritional status using a mini nutritional assessment short form (MNA-SF), cognitive function, activities of daily living, peak expiratory flow rate (PEFR) for pulmonary function, and tongue pressure were assessed. The associations between nutritional status and the above factors were analysed using a logistic regression model.

RESULTS

Participants were divided into two groups: well-nourished group (MNA-SF ≤12) and undernutrition group (MNA-SF <12). Multivariate logistic regression analysis revealed that the correlations of PEFR [odds ratio (OR) = 0.23, 95% confidence interval (CI) = 0.23-0.89 p=0.033) and tongue pressure (OR = 0.88, 95% CI = 0.88-0.99, p=0.029) remained significant even after adjustment with possible confounders.

CONCLUSION

Maximum tongue pressure and PEFR in older adults were significantly associated with their nutritional status. These findings suggest that maintaining oral and pulmonary function may be a preventive factor against a decrease in the nutritional status of older frail adults.

Association of Serum 25-Hydroxyvitamin D Concentration with Pulmonary Function in Young Adults

The role of vitamin D on pulmonary function is unclear and is mostly studied in patients, smokers and elderly people. The aim of this paper was to evaluate the association between serum 25-hydroxyvitamin D [25(OH)D] concentration and pulmonary function in young adults. Cross-sectional analysis of 499 individuals that were evaluated at 21 years of age as part of the population-based cohort Epidemiological Health Investigation of Teenagers in Porto (EPITeen). Serum 25(OH)D was categorized according to the Institute of Medicine. Pulmonary function was evaluated using spirometry. Linear regression models were used to estimate the regression coefficients (β) and its 95% confidence intervals (95% CI), and were adjusted for confounders. Education, smoking, body mass index, and season of evaluation were determinants of serum 25(OH)D concentration. Prevalence of serum 25(OH)D concentration <50 nmol/L was 48.9%. A decrease in all pulmonary function parameters, with the decrease of serum 25(OH)D, was observed. The higher effect was found for peak expiratory flow (PEF). Having as reference participants with serum 25(OH)D concentration ≥50 nmol/L, PEF was significantly lower for those with a concentration of 30 to <50 nmol/L (β= −0.576; 95% CI: −0.943, −0.210), and for those with a concentration of <30 nmol/L (β= −0.650; 95% CI: −1.155, −0.146). Although only PEF attained statistical significance, the consistent results with the other parameters support the role of serum 25(OH)D to promote better pulmonary function in young adults.

Associations of Serum 25(OH)D Concentrations with Lung Function, Airway Inflammation and Common Cold in the General Population

Vitamin D is hypothesized to have a beneficial effect on lung function and respiratory infections. The aim of this study was to assess the relationship of serum 25-hydroxyvitamin D (25(OH)D) concentrations with lung function, airway inflammation and common colds. We performed a cross-sectional analysis in the Netherlands Epidemiology of Obesity (NEO) study, a population-based cohort study. We included participants with measurements of serum 25(OH)D, Forced Expiratory Volume in 1 s (FEV₁), Forced Vital Capacity (FVC), Fractional Exhaled Nitric Oxide (Fe_NO), and data on self-reported common colds (n = 6138). In crude associations, serum 25(OH)D was positively associated with FEV₁ and FVC, and negatively with Fe_NO and the occurrence of a common cold. After adjustment for confounders, however, these associations disappeared. Stratified analyses showed that Body Mass Index (BMI) was an effect modifier in the relationship between serum 25(OH)D and FEV₁, FVC and Fe_NO. In obese participants (BMI ≥ 30 kg/m²), 10 nmol/L higher 25(OH)D was associated with 0.46% predicted higher FEV₁ (95% Confidence Interval: 0.17 to 0.75), 0.46% predicted higher FVC (0.18 to 0.74), and 0.24 ppb lower Fe_NO (−0.43 to −0.04). Thus, in the total study population, 25(OH)D concentrations were not associated with lung function, airway inflammation and common colds. In obese participants, however, higher 25(OH)D concentrations were associated with a better lung function and lower airway inflammation.

Effects of daily vitamin D supplementation on respiratory muscle strength and physical performance in vitamin D-deficient COPD patients: a pilot trial

Background

Although vitamin D is well known for its function in calcium homeostasis and bone mineralization, several studies have shown positive effects on muscle strength and physical function. In addition, vitamin D has been associated with pulmonary function and the incidence of airway infections. As vitamin D deficiency is highly prevalent in chronic obstructive pulmonary disease (COPD) patients, supplementation might have a beneficial effect in these patients.

Objective

To assess the effect of vitamin D supplementation on respiratory muscle strength and physical performance in vitamin D-deficient COPD patients. Secondary outcomes are pulmonary function, handgrip strength, exacerbation rate, and quality of life.

Methods

We performed a randomized, double-blind, placebo-controlled pilot trial. Participants were randomly allocated to receive 1,200 IU vitamin D3 per day (n=24) or placebo (n=26) during 6 months. Study visits were conducted at baseline, and at 3 and 6 months after randomization. During the visits, blood was collected, respiratory muscle strength was measured (maximum inspiratory and expiratory pressure), physical performance and 6-minute walking tests were performed, and handgrip strength and pulmonary function were assessed. In addition, participants kept a diary card in which they registered respiratory symptoms.

Results

At baseline, the mean (standard deviation [SD]) serum 25-hydroxyvitamin D (25(OH)D) concentration (nmol/L) was 42.3 (15.2) in the vitamin D group and 40.6 (17.0) in the placebo group. Participants with vitamin D supplementation had a larger increase in serum 25(OH)D compared to the placebo group after 6 months (mean difference (SD): +52.8 (29.8) vs +12.3 (25.1), P<0.001). Primary outcomes, respiratory muscle strength and physical performance, did not differ between the groups after 6 months. In addition, no differences were found in the 6-minute walking test results, handgrip strength, pulmonary function, exacerbation rate, or quality of life.

Conclusion

Vitamin D supplementation did not affect (respiratory) muscle strength or physical performance in this pilot trial in vitamin D-deficient COPD patients.

Effects of vitamin D supplementation on pulmonary function in postmenopausal women following an aquatic exercise program

OBJECTIVE

This study sought to investigate the effects of vitamin D supplementation and aquatic exercise on pulmonary function in postmenopausal women.

MATERIALS AND METHODS

This prospective and controlled study included 104 women (62 ± 6.5 years) divided into three groups: a control group lacking vitamin D and calcium supplementation which remained sedentary (CG; n = 17); a control group receiving vitamin D and calcium supplementation which remained sedentary (CDG, n = 33); and a group that completed aquatic exercises three times a week and received vitamin D and calcium supplementation (DTG, n = 54). Data before and after 6 months of the study were analyzed, including serum 25-hydroxyvitamin D (25(OH)D) and calcium concentrations, peak expiratory flow (PEF), forced vital capacity (FVC), and cirtometry.

RESULTS

We observed significant increases in 25(OH)D concentrations in CDG (52.9 ± 2.4 to 69.1 ± 2.2; nmol/L; p < 0.0001) and DTG groups (55.5 ± 3 to 71.5 ± 3 nmol/L; p < 0.0001). PEF increased by 7 ± 2% (p = 0.0080) in CDG group and 11 ± 2% (p < 0.0001) in DTG group, whereas FVC increased by 7 ± 2% (p = 0.0016) in the CDG group and 10 ± 2% (p < 0.0001) in the DTG group, whereas CG had no changes in any of these parameters. The increment value of cirtometry in DTG group (+43 ± 3%) were significantly (p < 0.0001) higher than those in CG (-4 ± 8%) and CDG (+4 ± 9%) groups.

CONCLUSION

Our data suggest that vitamin D supplementation improves pulmonary function parameters in postmenopausal women.

The Longitudinal Aging Study Amsterdam: cohort update 2016 and major findings

The Longitudinal Aging Study Amsterdam (LASA) is an ongoing longitudinal study of older adults in the Netherlands, which started in 1992. LASA is focused on the determinants, trajectories and consequences of physical, cognitive, emotional and social functioning. The study is based on a nationally representative sample of older adults aged 55 years and over. The findings of the LASA study have been reported in over 450 publications so far (see www.lasa-vu.nl). In this article we describe the background and the design of the LASA study, and provide an update of the methods. In addition, we provide a summary of the major findings from the period 2011–2015.

Prevention of exacerbations in patients with COPD and vitamin D deficiency through vitamin D supplementation (PRECOVID): a study protocol

Background

Vitamin D is well known for its function in calcium homeostasis and bone mineralisation, but is increasingly studied for its potential immunomodulatory properties. Vitamin D deficiency is a common problem in patients with COPD. Previous studies have not demonstrated a beneficial effect of vitamin D on exacerbation rate in COPD patients. However, subgroup analyses suggested protective effects in vitamin D deficient patients. Our objective is to assess the effect of vitamin D supplementation on exacerbation rate specifically in vitamin D deficient COPD patients.

Methods/Design

We will perform a randomised, multi-center, double-blind, placebo-controlled intervention study. The study population consists of 240 COPD patients aged 40 years and older with vitamin D deficiency (25-hydroxyvitamin D concentration < 50 nmol/L). Participants will be recruited after an exacerbation and will be randomly allocated in a 1:1 ratio to receive vitamin D3 16800 IU or placebo orally once a week during 1 year. Participants will receive a diary card to register the incidence of exacerbations and changes in medication during the study period. Visits will be performed at baseline, at 6 months and at 12 months after randomisation. Participants will undergo spirometry, measurement of total lung capacity and assessment of maximal respiratory mouth pressure. Several physical performance and hand grip strength tests will be performed, questionnaires on quality of life and physical activity will be filled in, a nasal secretion sample and swab will be obtained and blood samples will be taken. The primary outcome will be exacerbation rate.

Discussion

This study will be the first RCT aimed at the effects of vitamin D supplementation on exacerbation rate in vitamin D deficient COPD patients. Also, in contrast to earlier studies that used infrequent dosing regimens, our trial will study effects of a weekly dose of vitamin D supplementation. Secondly, the immunomodulatory effects of vitamin D on host immune response of COPD patients and underlying mechanisms will be studied. Finally, the effects on physical functioning will be examined.

Trial registration

This trial is registered in ClinicalTrials.gov, ID number NCT02122627. Date of Registration April 2014.

Thresholds for Serum 25(OH)D Concentrations With Respect to Different Outcomes

CONTEXT

Vitamin D is essential for bone health. In addition, vitamin D has recently been proposed to play a role in the pathophysiology of many chronic diseases. Despite the large number of studies published on vitamin D, the threshold for a sufficient serum 25-hydroxyvitamin D [25(OH)D] concentration is still debated and may differ according to outcomes and subgroups.

OBJECTIVE

The objective of the study was to estimate the thresholds for serum 25(OH)D concentration with respect to the different outcomes and for different subgroups.

DESIGN, SETTING, AND PARTICIPANTS

Observational data from the Longitudinal Aging Study Amsterdam, an ongoing population-based Dutch cohort study [n = 1164, mean (SD) age 75.2 (6.5) y], were used.

MAIN OUTCOME MEASURES

Falling, fractures, hypertension, cardiovascular disease, blood pressure, PTH, grip strength, physical performance, functional limitations, body mass index (BMI), and mortality were measured. To determine thresholds, spline curves were used. Visual inspection and the statistical best fit of the spline regression models were used together to estimate the best estimate of the thresholds.

RESULTS

Thresholds for serum 25(OH)D concentrations in the whole sample ranged from 46 nmol/L (PTH) to 68 nmol/L (hypertension). On average, women, the oldest old (≥ 75 y), and individuals with a high BMI (>25 kg/m(2)) had lower thresholds compared with men, the youngest old (65-75 y), and individuals with a low to normal BMI (<25 kg/m(2)).

CONCLUSION

The results indicate that thresholds for serum 25(OH)D may vary according to different outcomes and subgroups. This study does not support the high thresholds (>75 nmol/L) as advised by some experts, and the higher requirements in women, older persons, and those with high BMI.

Vitamin D as an adjunctive therapy in asthma. Part 2: A review of human studies

Vitamin D deficiency (VDD) is highly prevalent worldwide, with adverse effects on bone health but also potentially other unfavorable consequences. VDD and asthma-incidence/severity share many common risk factors, including winter season, industrialization, poor diet, obesity, dark skin pigmentation, and high latitude. Multiple anatomical areas relevant to asthma contain both the enzyme responsible for producing activated vitamin D and the vitamin D receptor suggesting that activated vitamin D (1,25-dihydroxyvitamin D) may have important local effects at these sites. Emerging evidence suggests that VDD is associated with increased airway hyperresponsiveness, decreased pulmonary function, worse asthma control, and possibly decreased response to standard anti-asthma therapy. However the effect is inconsistent with preliminary evidence from different studies suggesting vitamin D is both beneficial and detrimental to asthma genesis and severity. Current evidence suggests that supplementation with moderate doses of vitamin D may be appropriate for maintenance of bone health in asthmatics, particularly steroid users. However emerging data from an increasing number of randomized, controlled, intervention studies of vitamin D supplementation in pediatric and adult asthma are becoming available and should help determine the importance, if any of vitamin D for asthma pathogenesis. The purpose of this second of a two-part review is to review the current human literature on vitamin D and asthma, discussing the possible consequences of VDD for asthma and the potential for vitamin D repletion as adjunct therapy.

Serum 25-hydroxyvitamin D levels and lung function in adults with asthma: the HUNT Study

The association between vitamin D status and lung function in adults with asthma remains unclear. We studied this cross-sectional association and possible modification by sex and allergic rhinitis in 760 adults (aged 19-55 years) with self-reported asthma in the Nord-Trøndelag Health Study. Serum 25-hydroxyvitamin D (25(OH)D) level <50 nmol·L(-1) was considered deficient. Lung function measurements included forced expiratory volume in 1 s (FEV1) % predicted, forced vital capacity (FVC) % predicted and FEV1/FVC ratio. Multiple linear regression models were used to estimate adjusted regression coefficients (β) and 95% confidence intervals. 44% of asthma adults had serum 25(OH)D levels <50 nmol·L(-1). Its associations with lung function measures seemed to be modified by sex and allergic rhinitis (p<0.03 for three-way interaction term). Overall, a serum 25(OH)D level <50 nmol·L(-1) was not associated with lung function measurements in subjects with allergic rhinitis in this asthma cohort. In men with asthma but without allergic rhinitis, however, a serum 25(OH)D level <50 nmol·L(-1) was significantly associated with lower FEV1/FVC ratio (β=-8.60%; 95% CI: -16.95%- -0.25%). Low serum 25(OH)D level was not associated with airway obstruction in most asthma adults with the exception of men with asthma but without allergic rhinitis.

Plasma 25-hydroxyvitamin D associated with pulmonary function in Canadian adults with excess adiposity

BACKGROUND

Vitamin D deficiency is an important health issue, particularly among people residing in northern countries. Low concentrations of 25-hydroxyvitamin D [25(OH)D] have been linked to several health conditions.

OBJECTIVE

The objective was to determine the association between plasma 25(OH)D and pulmonary function and the effect modifications of sex and body mass index (BMI) in adults.

DESIGN

A cross-sectional study included 3359 adults aged ≥18 y who participated in the Canadian Health Measures Survey, and a 2-stage multiple linear regression analysis was conducted.

RESULTS

Overall, 26% of the adults had a plasma 25(OH)D concentration <50 nmol/L, which is considered deficient (ie, hypovitaminosis D). This deficiency was more prevalent among men than among women (30% compared with 23%). Regression analysis showed that deficient plasma 25(OH)D was associated with lower mean residual forced vital capacity and forced expiratory volume in 1 s in men after adjustment for covariates. When further stratified by BMI, the associations were more marked in overweight and obese men. Vitamin D deficiency associated with pulmonary function was not statistically significant in normal-weight men or in women, regardless of BMI categories. Similar results were obtained when plasma 25(OH)D was examined as a continuous variable in the models.

CONCLUSIONS

Hypovitaminosis D may be a risk factor for lung dysfunction, especially for overweight and obese men. Further research is necessary to determine the mechanism of the interrelation between vitamin D, adiposity, and pulmonary function.