Vitamin D status correlates with the markers of cystic fibrosis-related pulmonary disease

Dietary patterns and micronutrients in respiratory infections including COVID-19: a narrative review

BACKGROUND

COVID-19 is a pandemic caused by nCoV-2019, a new beta-coronavirus from Wuhan, China, that mainly affects the respiratory system and can be modulated by nutrition.

METHODS

This review aims to summarize the current literature on the association between dietary intake and serum levels of micronutrients, malnutrition, and dietary patterns and respiratory infections, including flu, pneumonia, and acute respiratory syndrome, with a focus on COVID-19. We searched for relevant articles in various databases and selected those that met our inclusion criteria.

RESULTS

Some studies suggest that dietary patterns, malnutrition, and certain nutrients such as vitamins D, E, A, iron, zinc, selenium, magnesium, omega-3 fatty acids, and fiber may have a significant role in preventing respiratory diseases, alleviating symptoms, and lowering mortality rates. However, the evidence is not consistent and conclusive, and more research is needed to clarify the mechanisms and the optimal doses of these dietary components. The impact of omega-3 and fiber on respiratory diseases has been mainly studied in children and adults, respectively, and few studies have examined the effect of dietary components on COVID-19 prevention, with a greater focus on vitamin D.

CONCLUSION

This review highlights the potential of nutrition as a modifiable factor in the prevention and management of respiratory infections and suggests some directions for future research. However, it also acknowledges the limitations of the existing literature, such as the heterogeneity of the study designs, populations, interventions, and outcomes, and the difficulty of isolating the effects of single nutrients from the complex interactions of the whole diet.

Vitamin D concentrations were often insufficient among native Norwegian adolescents and children with a non-Western immigrant background

AIM

The aim of this study was to review papers that assessed the vitamin D intake of children living in Norway, as research has suggested that it has remained below the recommended daily allowance of 10 μg/day.

METHODS

This mini review examined the vitamin D status of Norwegian children aged 0-18 years by systematically searching the PubMed, Google Scholar and Scopus databases from 1 January 2009 to 1 July 2020.

RESULTS

The review comprised six studies published in English between 2009 and 2020 on native-born and non-Western immigrant children. Most studies defined satisfactory vitamin D status as a plasma 25-hydroxyvitamin D (25(OH)D) concentration of 50 nmol/L, with 25-50 nmol/L being classified as insufficient and below 25 nmol/L being classified as deficient. A study of healthy children found that 21% had insufficient levels and a further 1% were deficient, but this second finding was only among adolescents. Other studies showed that 47% of Norwegian children with a non-Western immigrant background were deficient, and so were 19% of overweight children, mainly adolescents.

CONCLUSION

Vitamin D concentrations were often insufficient among children living in Norway, particularly adolescents and those with a non-Western immigrant background. Higher recommended supplements may be needed.

Systematic review and meta-analysis: Associations of vitamin D with pulmonary function in children and young people with cystic fibrosis

BACKGROUND

Increasing evidence suggests that vitamin D is associated with pulmonary health, which may benefit children and young people diagnosed with Cystic Fibrosis (cypCF). Therefore, the aim of this systematic review was to evaluate primary research to establish associations between 25OHD and pulmonary health in cypCF.

METHODS

Electronic databases were searched with keywords related to CF, vitamin D, children/young people and pulmonary function. Included studies were cypCF (aged ≤21 years) treated in a paediatric setting. The primary outcome was lung function [forced expiratory volume in 1 s (FEV₁% predicted)] and secondary outcomes were rate of pulmonary exacerbations, 25OHD status and growth. Evidence was appraised for risk of bias using the CASP tool, and quality using the EPHPP tool. A Meta-analysis was performed.

RESULTS

Twenty-one studies were included with mixed quality ratings and heterogeneity of reported outcomes. The Meta-analysis including 5 studies showed a significantly higher FEV₁% predicted in the 25OHD sufficiency compared to the deficiency group [FEV₁% predicted mean difference (95% CI) was 7.71 (1.69-13.74) %; p = 0.01]. The mean ± SD FEV₁% predicted for the sufficient (≥75 nmol/L) vs. deficient (<50 nmol/L) group was 94.7 ± 31.9% vs. 86.9 ± 13.2%; I² = 0%; χ² = 0.5; df = 4). Five studies (5/21) found significantly higher rate of pulmonary exacerbations in those who were 25OHD deficient when compared to the sufficient group and negative associations between 25OHD and FEV% predicted. The effects of vitamin D supplementation dosages on 25OHD status (10/21) varied across studies and no study (12/21) showed associations between 25OHD concentration and growth.

CONCLUSION

This systematic review suggests that 25OHD concentration is positively associated with lung function and a concentration of >75 nmol/L is associated with reduced frequency of pulmonary exacerbations, which may slow lung function decline in cypCF. Future randomised clinical trials and mechanistic studies are warranted.

Vitamin Status in Children with Cystic Fibrosis Transmembrane Conductance Regulator Gene Mutation

Background: The issue of vitamin metabolism in children with cystic fibrosis screen positive, inconclusive diagnosis (CFSPID) is not well known. The aim of this study was to determine the status of vitamins A, D, E, and C in the blood of a group of children with CFSPID. Material and Methods: A total of 89 children were enrolled in the study (Me: 3.6 years, 52.8% boys), as follows: 28 with CFSPID, 31 with CF (cystic fibrosis), and 30 HC (healthy children). Their blood concentrations of vitamins A, D, E, and C, and their dietary intake of these vitamins were analysed in the study groups on the basis of a three-day food diary. Results: The patients with CFSPID had significantly higher serum vitamin D (p = 0.01) and E (p = 0.04) concentrations, compared to the children with CF. None of the children with CFSPID revealed vitamin A or E deficiencies. Patients with CF had been consuming significantly higher vitamin D and E amounts (p = 0.01). The vitamin concentrations did not depend either on the pancreatic/liver function or on anthropometric parameters. In total, 32.14% of patients with CF did not cover the baseline recommended calorie intake, and 53.6% and 36% did not take the recommended vitamin E and vitamin A intake, respectively. Conclusion: Children with CF and CFSPID did not fully cover the dietary recommendations for vitamin supply, but vitamin deficiency was found only in CF.

Update on the management of vitamins and minerals in cystic fibrosis

Advancements in respiratory and nutrition management have significantly improved the survival of patients with cystic fibrosis (CF). With the availability of several nutrition interventions such as oral/enteral nutrition supplements, enteric‐coated pancreatic enzymes, and water‐miscible CF‐specific vitamin supplements, frank vitamin deficiencies—with the exception of vitamin D—are rarely encountered in current clinical practice. Whereas they were previously considered as micronutrients, our current understanding of fat‐soluble vitamins and minerals as antioxidants, immunomodulators, and disease biomarkers has been evolving. The impact of highly effective modulators on the micronutrient status of patients with CF remains elusive. This narrative review focuses on the updates on the management of fat‐soluble vitamins and other micronutrients in CF in the current era and identifies the gaps in our knowledge.

The Relation between Vitamin D Level and Lung Clearance Index in Cystic Fibrosis—A Pilot Study

Background: Life expectancy has increased in cystic fibrosis (CF) patients; however, the rate of mortality is still high, and in a majority of cases, the cause of death is due to respiratory deterioration. Vitamin D plays an important role in immunity and infection prophylaxis, as its deficiency is associated with frequent infections. In CF patients, a deficit of liposoluble vitamins is common, despite daily supplementation. The aim of this study is to evaluate the relation between vitamin D status and lung function expressed by lung clearance index (LCI) in patients with CF. We also assessed the relation of factors such as nutritional status, genotype, and associated comorbidities such as Pseudomonas infection, cystic fibrosis-related diabetes (CFRD), and cystic fibrosis liver disease (CFLD) with vitamin D and LCI. Methods: A cross-sectional study was conducted at the National Cystic Fibrosis Center by analyzing patients with CF who presented in our center between November 2017 and November 2019. We enrolled in the study patients diagnosed with CF, who were followed up in our CF center and who were able to perform lung function tests. Patients in exacerbation were excluded. Results: A strong negative correlation was found between vitamin D and LCI (r = −0.69, p = 0.000). A lower vitamin D storage was found in patients with CFLD and CFRD. Higher LCI values were found among patients with chronic Pseudomonas infection, with BMI under the 25th percentile, or with associated CFLD. Conclusion: In CF patients, vitamin D plays an important role, and its deficit correlates with an impaired LCI. Vitamin D deficit is a risk factor in patients with associated comorbidities such as CFLD and CFRD. Chronic infection with Pseudomonas, the presence of impaired nutritional status, and CFLD are associated with a prolonged LCI.

Impact of vitamin D status on CF and non-CF bronchiectasis outcomes

Background

Vitamin D deficiency occurs frequently in cystic fibrosis (CF) and non-CF bronchiectasis patients. Yet, few studies have assessed the impact of vitamin D status on the clinical outcomes in pediatric bronchiectasis. This study is designed to assess vitamin D level and determine its effect on exacerbations, bacterial colonization, and lung function in pediatric patients with CF and non-CF bronchiectasis.

Results

This cross-sectional case-control study assessing vitamin D level was performed in a total of sixty cases under the age of 18 years—forty cases with CF and non-CF bronchiectasis and twenty age- and sex-matched healthy controls. Associations between serum vitamin D and clinical and laboratory parameters were assessed in the patient groups. Vitamin D deficiency was more prevalent among CF and non-CF bronchiectasis patients (75%, 45%) compared to controls (10%) (P < 0.001). In addition, vitamin D deficiency was associated with more frequent and severe pulmonary exacerbations (66.7%, 46.7%) (P=0.033, < 0.001), chronic Pseudomonas infection (80%) (P=0.060) among CF patients, and with lower FEV1 (66%) (P= 0.071) among non-CF bronchiectasis. Moreover, a cutoff value of vitamin D level equal or less than 22.5 ng/ml was accurate in differentiating moderate from mild pulmonary exacerbations in both patients’ groups (AUC=0.809) (p=0.004).

Conclusions

Vitamin D deficiency is not uncommon in both CF and non-CF bronchiectasis. In this population, vitamin D deficiency is associated with more frequent pulmonary exacerbations, chronic Pseudomonas infection, and worse lung function.

A Clinician’s guide to vitamin D supplementation for patients with cystic fibrosis

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Vitamin D deficiency is multifactorial in the cystic fibrosis population.

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Vitamin D deficiency can adversely affect multiple organ systems in the cystic fibrosis population.

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In the cystic fibrosis population in the United States, we aim to treat to serum 25-hydroxyvitamin D levels over 30 ng/ml.

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Cholecalciferol is used in preference to ergocalciferol.

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Daily or once weekly dosing regimens are chosen according to patient preference and compliance.

Vitamin D deficiency is common in the general population, and even more so in patients with cystic fibrosis. Deficiency is exacerbated in cystic fibrosis patients because of a myriad of causes including malabsorption, decreased fat mass, reduced 25-hydroxylation of vitamin D, reduced exposure to sunlight, decreased vitamin D binding protein, and exposure to drugs that increase catabolism. In turn, vitamin D deficiency can contribute to poor bone health. Additionally, it may contribute to pulmonary decline in the form of worsening pulmonary function, increased colonization with pathogens, and increased pulmonary exacerbation. Because vitamin D deficiency is correlated with negative clinical effects in multiple organ systems of patients with cystic fibrosis, it is important to screen for and treat deficiency in these patients. The Cystic Fibrosis Foundation has issued guidelines for the treatment of vitamin D deficiency, targeting serum levels of 25-hydroxyvitamin D of at least 30 ng/ml. The guidelines offer age-specific escalating dose regimens depending on serum vitamin D levels, with monitoring at 12- week intervals after changing therapy. They address the literature on alternative vitamin D sources, such as UV lamps, ideal formulations (cholecalciferol in preference to ergocalciferol), and optimal vehicles of administration. Despite these detailed recommendations, most centers are still unable to achieve in-target serum vitamin D levels for many of their patients. Future research examining ideal treatment regimens to achieve serum targets and maximize clinical effects are needed. Moreover, it is unknown whether vitamin D sufficiency will be easier to achieve on new triple therapy cystic fibrosis drug combinations, and how these drugs will contribute to vitamin D-related clinical outcomes.

DeltaF508 CFTR Hetero- and Homozygous Paediatric Patients with Cystic Fibrosis Do Not Differ with Regard to Nutritional Status

The purpose of this study was to compare the nutritional status between deltaF508 CFTR hetero- and homozygous paediatric patients with cystic fibrosis. We assessed the percentage profiles of fatty acids measured in erythrocyte membranes and the serum levels of vitamins A, D3, E and K1 in the studied groups. We also measured the weights and heights and calculated the body mass indexes (BMIs). The studied groups consisted of 34 heterozygous and 30 homozygous patients. No statistically significant differences were found in the serum vitamins or erythrocyte membrane fatty acid profiles between the hetero- and homozygous patient groups, except for heptadecanoic acid (p = 0.038). The mean percentiles of height, weight and BMI did not differ significantly between the two groups. The homozygous and heterozygous paediatric patients with cystic fibrosis were similar in terms of their nutritional statuses.

Vitamin D status and pulmonary exacerbations in children and adolescents with cystic fibrosis: Experience from a tertiary care center

Background:

The function of Vitamin D in preventing inflammation and infection has been studied previously for different pathologies in different populations globally. Relationships between serum Vitamin D levels and its effect on pulmonary exacerbations in the cystic fibrosis (CF) population are not well studied in our part of the world. Therefore, we aimed to ascertain the Vitamin D status in pediatric and adolescent CF patients and its association with pulmonary exacerbations.

Materials and Methods:

A retrospective study was conducted at The Aga Khan University Hospital from 2015 to 2018. Patients of CF with sweat chloride value >60 mmol/l and who had at least one measurement of 25 hydroxy Vitamin D (25 OHD) were included in the study. Annual serum Vitamin D levels were documented for enrolled patients and their past 1-year data were analyzed for pulmonary exacerbations, average length of stay, and tracheal/airway colonization with organisms.

Results:

69 patients were included in the study. 28 patients (40.57%) were found to be Vitamin D deficient, 22 patients (31.88%) were Vitamin D insufficient and 19 patients (27.53%) were labeled as Vitamin D insufficient. The average number of exacerbations per year was significantly high in Vitamin D deficient group (3.71 ± 0.96) in comparison with insufficient (3.18 ± 1.09) and sufficient groups (2.26 ± 0.93) (P < 0.001).

Conclusion:

Vitamin D deficiency is related to an increased number of annual pulmonary exacerbations and pseudomonas infections.

Updated information on new coronavirus disease 2019 occurrence, drugs, and prediction of a potential receptor

The new coronavirus (COVID-19) was first reported in Wuhan in China, on 31 December 2019. COVID-19 is a new virus from the family of coronaviruses that can cause symptoms ranging from a simple cold to pneumonia. The virus is thought to bind to the angiotensin-converting enzyme 2, as a well-known mechanism to enter the cell. It then transfers its DNA to the host in which the virus replicates the DNA. The viral infection leads to severe lack of oxygen, lung oxidative stress because of reactive oxygen species generation, and overactivation of the immune system by activating immune mediators. The purpose of this review is to elaborate on the more precise mechanism(s) to manage the treatment of the disease. Regarding the mechanisms of the virus action, the suggested pharmacological and nutritional regimens have been described.

Associations of VDR gene polymorphisms with risk of coal workers' pneumoconiosis in Chinese Han population

Some studies showed that the polymorphisms of vitamin D receptor (VDR) gene were associated with pulmonary diseases. However, the relationship between the VDR variations and susceptibility to coal worker's pneumoconiosis (CWP) remains unclear. The study aimed to determine the associations between VDR polymorphisms and susceptibility to CWP in Chinese Han population. The study involved 340 CWP patients and 312 healthy controls. The VDR polymorphisms were determined by DNA sequencing, and serum 25(OH)2D levels were detected by Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry. The results showed that the VDR gene ApaI T allele increased the risk of CWP (OR = 1.486, 95% CI = 1.125-1.963, P = 0.006) and ApaI GT genotype as well as TT genotype increased the risk of CWP (GT vs. GG, OR = 1.461, 95% CI = 1.048-2.038, P = 0.025; TT vs. GG, OR = 2.673, 95% CI = 1.017-7.025, P = 0.039). Five haplotypes were identified and we found that the TGGT haplotype was associated with a lower risk of CWP (OR = 0.755, 95% CI = 0.603-0.946, P = 0.014). Meanwhile, multifactor dimensionality reduction analysis showed that the interaction between ApaI and exposure was the strongest, followed by TaqI and then BsmI. The study also found that the serum 25(OH)2D mean levels of the case group were significantly lower than that of the control group, and the serum 25(OH)2D mean levels of ApaI homozygous mutant and heterozygous mutant subjects were lower than that of the wild homozygosity, respectively (P < 0.001). The results suggested that ApaI T allele and GT or TT genotype and lower 25(OH)2D levels were increased the risk of CWP in Chinese Han population.

Impact of the Local Inflammatory Environment on Mucosal Vitamin D Metabolism and Signaling in Chronic Inflammatory Lung Diseases

Vitamin D plays an active role in the modulation of innate and adaptive immune responses as well as in the protection against respiratory pathogens. Evidence for this immunomodulatory and protective role is derived from observational studies showing an association between vitamin D deficiency, chronic airway diseases and respiratory infections, and is supported by a range of experimental studies using cell culture and animal models. Furthermore, recent intervention studies have now shown that vitamin D supplementation reduces exacerbation rates in vitamin D-deficient patients with chronic obstructive pulmonary disease (COPD) or asthma and decreases the incidence of acute respiratory tract infections. The active vitamin D metabolite, 1,25-dihydroxy-vitamin D (1,25(OH)₂D), is known to contribute to the integrity of the mucosal barrier, promote killing of pathogens (via the induction of antimicrobial peptides), and to modulate inflammation and immune responses. These mechanisms may partly explain its protective role against infections and exacerbations in COPD and asthma patients. The respiratory mucosa is an important site of local 1,25(OH)₂D synthesis, degradation and signaling, a process that can be affected by exposure to inflammatory mediators. As a consequence, mucosal inflammation and other disease-associated factors, as observed in e.g., COPD and asthma, may modulate the protective actions of 1,25(OH)₂D. Here, we discuss the potential consequences of various disease-associated processes such as inflammation and exposure to pathogens and inhaled toxicants on vitamin D metabolism and local responses to 1,25(OH)₂D in both immune- and epithelial cells. We furthermore discuss potential consequences of disturbed local levels of 25(OH)D and 1,25(OH)₂D for chronic lung diseases. Additional insight into the relationship between disease-associated mechanisms and local effects of 1,25(OH)₂D is expected to contribute to the design of future strategies aimed at improving local levels of 1,25(OH)₂D and signaling in chronic inflammatory lung diseases.

Association of vitamin D status with lung function measurements in children and adolescents with cystic fibrosis

BACKGROUND

Vitamin D status is considered a potential determinant of lung function in cystic fibrosis (CF). The aim of this retrospective longitudinal study was to investigate the decline of spirometric values in association with vitamin D status.

METHODS

The data regarding 25-hydroxy vitamin D (25OHD) serum levels, spirometric measurements (FEV1, FVC, FEF25-75%), and factors known to be associated with the decline of lung function in CF were retrospectively collected over a 5-year period. The spirometric indices were recorded as the best and the average value of each year, as well as the value, recorded concurrently or closely with 25OHD level measurement.

RESULTS

A significantly positive relationship was observed between 25OHD serum levels and the best annual value of FEV1 (P = .034), and the values of FEV1 (P = .010) and FVC (P = .018) measured concurrently or closely with serum 25OHD levels. The evolution of the best annual value of FEV1 was worse in patients with a mean 5-year value of 25OHD levels less than 20 ng/mL compared with patients with a mean 5-year value of ≥30 ng/mL (P < .001), or ≥20 to <30 (P < .001). There was no significant difference between patients with mean 5-year 25OHD levels ≥30 ng/mL and ≥20 to <30 ng/mL (P = .76).

CONCLUSIONS

Vitamin D status is associated with lung function in patients with CF. Levels of 25OHD above 20 ng/mL were associated with higher best annual FEV1.

Targeting Vitamin D Deficiency to Limit Exacerbations in Respiratory Diseases: Utopia or Strategy With Potential?

Patients with respiratory diseases such as cystic fibrosis, chronic obstructive pulmonary disease, or asthma often experience an acute worsening of respiratory symptoms, termed exacerbations. Although the course of exacerbations is disease specific, they are mostly triggered by a respiratory infection. Exacerbations often require hospitalization and are an important cause of mortality. Treatments of exacerbations aim to minimize the negative impact and to prevent subsequent events. Despite many existing therapy options, many patients do not benefit from therapy and suffer from recurrent events. Vitamin D deficiency is a worldwide problem and is extremely prevalent in these patients. Vitamin D, known for its calcemic effects, also has immunomodulatory and anti-infectious actions and can therefore be a possible agent to treat or prevent exacerbations. This review will focus on vitamin D as a potential candidate to treat or prevent exacerbations in CF, COPD, and asthma.

Vitamin D inhibits pro-inflammatory cytokines in the airways of cystic fibrosis patients infected by Pseudomonas aeruginosa- pilot study

Background

Vitamin D plays an important role in inflammatory responses after antigen exposure. Interleukin-23 (Il-23) promotes Il-17-dependent inflammation during Pseudomonas aeruginosa (P. aeruginosa) pulmonary infection. We aimed to compare the ability of calcitriol and cholecalciferol to modulate the inflammatory response of the CF airways infected with P. aeruginosa.

Methods

This was a randomized, placebo-controlled, double-blind, cross-over trial. Twenty-three patients with CF (aged 6–19), chronically infected by P. aeruginosa were randomly assigned to: calcitriol group receiving 1,25(OH)₂D 0,5 mcg daily or cholecalciferol group receiving cholecalciferol 1000 IU daily for three months. The levels of Il-23 and Il-17A in the exhaled breath concentrate (EBC) were measured. Calcium-phosphorus balance was also evaluated (serum concentration of calcium, phosphorus, 25OHD, parathormone (PTH) and calcium/creatinine ratio in urine). Data were analyzed using means of Stata/Special Edition, release 14.2. A level of P < 0.05 was considered statistically significant.

Results

The level of Il-17A in EBC significantly decreased in calcitriol group from 0,475 pg/mL (± SD 0,515 pg/mL) to 0,384 pg/mL (± SD 0,429 pg/mL) (p = 0,008); there was no change in cholecalciferol group (p = 0,074). The level of Il-23 in EBC did not significantly change in calcitriol group (p = 0,086); there was significant decrease in cholecalciferol group from 8,90 pg/mL (± SD 4,07 pg/mL) to 7,33 pg/mL (± SD 3,88 pg/mL) (p = 0,001). In calcitriol group serum phosphorus and PTH significantly decreased (p = 0,021 and p = 0,019 respectively), the concentration of calcium significantly increased (p = 0,001); there were no changes in cholecalciferol group.

Conclusions

Both analogs of vitamin D revealed their anti-inflammatory effect and reduced the level of Il-17A and Il-23 in the airway of CF patients with chronic P. aeruginosa infection. We observed improvement in calcium-phosphorus metabolism after supplementation with calcitriol, without adverse effects. It is recommended to use vitamin D in CF patients.