-
BMC Geriatrics Jan 2017Sunlight exposure and high vitamin D status have been hypothesised to reduce the risk of developing dementia. The objective of our research was to determine whether lack... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sunlight exposure and high vitamin D status have been hypothesised to reduce the risk of developing dementia. The objective of our research was to determine whether lack of sunlight and hypovitaminosis D over time are associated with dementia.
METHODS
We systematically searched MEDLINE (via PubMed), Cochrane Library, EMBASE, SCOPUS, Web of Science, ICONDA, and reference lists of pertinent review articles from 1990 to October 2015. We conducted random effects meta-analyses of published and unpublished data to evaluate the influence of sunlight exposure or vitamin D as a surrogate marker on dementia risk.
RESULTS
We could not identify a single study investigating the association between sunlight exposure and dementia risk. Six cohort studies provided data on the effect of serum vitamin D concentration on dementia risk. A meta-analysis of five studies showed a higher risk for persons with serious vitamin D deficiency (<25 nmol/L or 7-28 nmol/L) compared to persons with sufficient vitamin D supply (≥50 nmol/L or 54-159 nmol/L) (point estimate 1.54; 95% CI 1.19-1.99, I = 20%). The strength of evidence that serious vitamin D deficiency increases the risk of developing dementia, however, is very low due to the observational nature of included studies and their lack of adjustment for residual or important confounders (e.g. ApoE ε4 genotype), as well as the indirect relationship between Vitamin D concentrations as a surrogate for sunlight exposure and dementia risk.
CONCLUSIONS
The results of this systematic review show that low vitamin D levels might contribute to the development of dementia. Further research examining the direct and indirect relationship between sunlight exposure and dementia risk is needed. Such research should involve large-scale cohort studies with homogeneous and repeated assessment of vitamin D concentrations or sunlight exposure and dementia outcomes.
Topics: Cohort Studies; Dementia; Female; Humans; Risk Factors; Sunlight; Vitamin D; Vitamin D Deficiency
PubMed: 28086755
DOI: 10.1186/s12877-016-0405-0 -
Revista Brasileira de Ginecologia E... Apr 2022To estimate the prevalence of inadequate vitamin D level and its associated factors for women of childbearing age in Brazil. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To estimate the prevalence of inadequate vitamin D level and its associated factors for women of childbearing age in Brazil.
METHODS
A systematic review was conducted (last updated May 2020). Meta-analyses were performed using the inverse-variance for fixed models with summary proportion calculation by Freeman-Tukey double arcsine. Reporting and methodological quality were assessed using the Joanna Briggs Institute tool for prevalence studies.
RESULTS
Our review identified 31 studies, comprising 4,006 participants. All the studies had at least one weakness, mainly due to the use of convenience sampling and small sample size. The overall prevalence of vitamin D deficiency, insufficiency, and both deficiency and insufficiency were 35% (confidence interval, 95%CI: 34-37%), 42% (95%CI: 41-44%), and 72% (95%CI: 71-74%), respectively.
CONCLUSION
Although the magnitude of the prevalence of inadequate levels of vitamin D is uncertain, the evidence suggests that presence of vitamin D deficiency or insufficiency in women of reproductive age can cause moderate to severe problems.
Topics: Brazil; Female; Humans; Prevalence; Vitamin D; Vitamin D Deficiency; Vitamins
PubMed: 35211934
DOI: 10.1055/s-0042-1742409 -
Pancreatology : Official Journal of the... 2016Patients with chronic pancreatitis (CP) are at risk of malnutrition due to malabsorption, pain and/or alcohol consumption. This can cause vitamin D insufficiency or... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND/OBJECTIVES
Patients with chronic pancreatitis (CP) are at risk of malnutrition due to malabsorption, pain and/or alcohol consumption. This can cause vitamin D insufficiency or deficiency, which is associated with osteoporosis and increased risks of fractures. We aimed to perform a meta-analysis to determine the prevalence of vitamin D insufficiency and deficiency in CP patients. Furthermore, we compared these results with healthy controls.
METHODS
We performed a systematic review and meta-analysis on the literature by searching PubMed and EMBASE (January 2000-December 2015) on CP and vitamin D. Primary outcome was prevalence of vitamin D insufficiency (<75 nmoL/L) and deficiency (<50 nmoL/L) in CP patients. When available, data of CP patients were compared with healthy controls.
RESULTS
Nine studies were included in our meta-analysis, reporting on the prevalence of vitamin D insufficiency/deficiency in 465 patients (mean age 41 years (range 18-60), 81% male) and in 378 controls (mean age 40 years (range 18-67), 76% male). Pooled prevalence of vitamin D insufficiency and deficiency in CP patients was 83% and 65%, respectively. Calculated odds ratio (OR) of vitamin D insufficiency and deficiency between CP patients and controls was 1.34 (0.54-3.29) and 1.14 (0.70-1.85), respectively (p > 0.05).
CONCLUSION
There is a high prevalence of vitamin D insufficiency and deficiency in CP patients. Nevertheless, there is no significant difference in prevalence of vitamin D insufficiency and deficiency compared to healthy controls. Further research should indicate the clinical relevance and consequences of these findings for clinical practice.
Topics: Humans; Pancreatitis, Chronic; Prevalence; Vitamin D; Vitamin D Deficiency
PubMed: 27453461
DOI: 10.1016/j.pan.2016.07.010 -
Clinical Endocrinology Mar 2022We sought to evaluate the association between vitamin D deficiency and the severity of coronavirus disease 2019 (COVID-19) infection. (Meta-Analysis)
Meta-Analysis
BACKGROUND
We sought to evaluate the association between vitamin D deficiency and the severity of coronavirus disease 2019 (COVID-19) infection.
METHODS
Multiple databases from 1 January 2019 to 3 December 2020 were searched for observational studies evaluating the association between vitamin D deficiency and severity of COVID-19 infection. Independent reviewers selected studies and extracted data for the review. The main outcomes of interest were mortality, hospital admission, length of hospital stay and intensive care unit admission.
RESULTS
Seventeen observational studies with 2756 patients were included in the analyses. Vitamin D deficiency was associated with significantly higher mortality (odds ratio [OR]: 2.47, 95% confidence interval [CI]: 1.50-4.05; 12 studies; hazard ratio [HR]: 4.11, 95% CI: 2.40-7.04; 3 studies), higher rates of hospital admissions (OR: 2.18, 95% CI: 1.48-3.21; 3 studies) and longer hospital stays (0.52 days; 95% CI: 0.25-0.80; 2 studies) as compared to nonvitamin D deficient status. Subgroup analyses based on different cut-offs for defining vitamin D deficiency, study geographic locations and latitude also showed similar trends.
CONCLUSIONS
Vitamin D deficiency is associated with greater severity of COVID-19 infection. Further studies are warranted to determine if vitamin D supplementation can decrease the severity of COVID-19.
Topics: COVID-19; Humans; Intensive Care Units; SARS-CoV-2; Vitamin D; Vitamin D Deficiency
PubMed: 34160843
DOI: 10.1111/cen.14540 -
Nutrients Jan 2023The aim of the present review was to summarize the current evidence about the impact of vitamin D deficiency on pathology and clinical manifestations of Sjögren's... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The aim of the present review was to summarize the current evidence about the impact of vitamin D deficiency on pathology and clinical manifestations of Sjögren's disease (SD).
METHODS
Databases PubMed, Web of Science, Scopus, and Cochrane library were searched for studies assessing the levels of vitamin D in SD patients using the following keywords: (vitamin D OR calciferol OR cholecalciferol OR 25-hydroxyvitamin D OR 25-hydroxycholecalciferol OR calcidiol OR calcitriol OR 1,25-dihydroxycholecalciferol) AND (Sjögren's Syndrome OR Sjögren's disease) accessed on 20 September 2022. Out of 248 retrieved studies, following the systematic review methodology and defined inclusion and exclusion criteria, 9 clinical studies were eligible to be included in the present review: 4 of them case-control, 4 cross-sectional, and 1 cohort study.
RESULTS
Nine studies totaling 670 SD patients and 857 healthy controls were eligible for meta-analysis with moderate to high methodological quality as determined by the Newcastle-Ottawa Quality Scale (NOS). According to the obtained results, a high prevalence of hypovitaminosis D was observed in SD patients when compared to healthy controls (95% CI -10.43, -2.39; < 0.01).
CONCLUSION
Available evidence points to lower levels of vitamin D in patients with SD in comparison to healthy controls. However, further studies are necessary to understand the underlying mechanisms associated with the role of vitamin D in the development and disease severity of SD.
Topics: Humans; Sjogren's Syndrome; Cohort Studies; Cross-Sectional Studies; Vitamin D; Vitamins; Calcifediol; Vitamin D Deficiency
PubMed: 36771203
DOI: 10.3390/nu15030497 -
Nutrition Reviews Sep 2023Vitamin D deficiency is considered a global public health issue, even in low-latitude countries where there is abundant sunlight radiation. Nevertheless, the... (Meta-Analysis)
Meta-Analysis
CONTEXT
Vitamin D deficiency is considered a global public health issue, even in low-latitude countries where there is abundant sunlight radiation. Nevertheless, the prevalence of vitamin D insufficiency and deficiency in the South American continent has not been well characterized.
OBJECTIVE
The aim of this review was to estimate the prevalence of vitamin D deficiency (25-hydroxy-calciferol < 20 ng/mL) in South American populations.
DATA SOURCES
Seven electronic databases (MEDLINE, Web of Science, Embase, Biblioteca Virtual de Saúde, SciELO, Scopus, and Google Scholar) were searched systematically for observational studies published before July 1, 2021, and reporting vitamin D status of healthy adults in South America.
DATA EXTRACTION
Data were extracted using a standardized form. Risk of bias was assessed by the Joanna Briggs Institute Critical Appraisal Instrument for Studies Reporting Prevalence. All steps were conducted independently by two authors. Data were pooled using a random-effects model. Stratified meta-analysis and meta-regression were conducted (R software).
DATA ANALYSIS
Of 9460 articles identified, 96 studies with a total of 227 758 participants were included. The overall prevalence of vitamin D deficiency was 34.76% (79 studies; 95%CI, 29.68-40.21; I2 = 99%). There were significant differences in prevalence rates related to age, sex, country, latitude, season, and year of publication.
CONCLUSION
The prevalence of vitamin D deficiency is unexpectedly elevated in South American populations. Public health strategies should include efforts to prevent, detect, and treat vitamin D deficiency.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO registration number CRD42020169439.
Topics: Adult; Humans; Prevalence; Vitamin D Deficiency; Vitamin D; Vitamins; South America
PubMed: 36882047
DOI: 10.1093/nutrit/nuad010 -
Critical Reviews in Food Science and... 2023Vitamin D deficiency is a worldwide health problem. However, the prevalence of vitamin D deficiency in Asian populations is unclear. The aims of our study were to... (Meta-Analysis)
Meta-Analysis
Vitamin D deficiency is a worldwide health problem. However, the prevalence of vitamin D deficiency in Asian populations is unclear. The aims of our study were to investigate the prevalence of vitamin D deficiency and its association with different health outcomes in Asia. Searches for studies published from January 2009 to January 2021 were performed in the MEDLINE (via PubMed), EMBASE, and Web of Science databases. This study was registered in the PROSPERO database (CRD42021229841). In total, 472 studies with 746,564 subjects were included in the meta-analysis. The mean serum 25-hydroxyvitamin D (25[OH]D) concentration was 49.39 nmol/L; 20.93% of the participants had 25(OH)D levels <25 nmol/L, 22.82% had levels <30 nmol/L, 57.69% had levels <50 nmol/L, and 76.85% had levels <75 nmol/L. This review found that the prevalence of vitamin D deficiency in Asia is high. The factors significantly related to vitamin D deficiency were gender, age, altitude, region, and specific diseases (diabetes, cancer, fracture, systemic lupus erythematosus [SLE], fatty liver disease, osteopenia, thyroiditis, anemia, hepatitis, metabolic diseases, and dermatitis). These findings may serve as the foundation for more detailed public health strategies and policies on this issue.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1990850.
Topics: Humans; Prevalence; Vitamin D Deficiency; Vitamin D; Asia; Lupus Erythematosus, Systemic; Global Health
PubMed: 34783278
DOI: 10.1080/10408398.2021.1990850 -
Journal of Global Health Aug 2023Vitamin A deficiency (VAD) is widely recognised as a major public health concern in low- and middle-income countries (LMICs). Despite various interventions implemented...
BACKGROUND
Vitamin A deficiency (VAD) is widely recognised as a major public health concern in low- and middle-income countries (LMICs). Despite various interventions implemented in many countries, a lack of reliable data is hindering progress. We aimed to consolidate available data and quantify estimates of the prevalence of VAD among children ≤18 years in LMICs.
METHODS
We searched PubMed, Medline and Embase for studies reported the prevalence of VAD or marginal (m)VAD among children. A multilevel mixed-effects meta-regression approach was applied to establish the regression models for VAD and mVAD prevalence. The total numbers of children affected by VAD and mVAD in LMICs in 2019 were separately calculated from the estimated age- and socio-demographic index (SDI)-specific prevalence with their corresponding United Nations Population Division populations projections. We estimated areas of significant public health concern in 165 LMICs using the lower confidence interval (CI) of VAD prevalence.
RESULTS
A total of 116 articles from 40 LMICs were retained. In 2019, VAD and mVAD affected 333.95 million (95% CI = 253.00-433.74) and 556.13 million (95% CI = 388.83-767.94) children and adolescents in 165 LMICs, respectively, corresponding to a prevalence of 14.73% (95% CI = 11.16-19.14) and 24.54% (95% CI = 17.15-33.88). The prevalence of both VAD and mVAD was the highest in children aged 0-5 years at 19.53% (95% CI = 15.03-24.91) and 28.22% (95% CI = 20.00-38.24), respectively, with both steadily decreasing to 10.09% (95% CI = 7.44-13.50) and 20.76% (95% CI = 14.16-29.50) in adolescents aged 13-18 years. The prevalence of VAD was significantly higher in the low SDI region at 29.67% (95% CI = 22.67-37.53) compared to 5.17% (95% CI = 3.14-8.43) estimated in the high-middle SDI region. 68 of the 165 LMICs (41.21%) were classified as areas of moderate to severe VAD public health significance.
CONCLUSIONS
VAD continues to pose a significant public health concern in many low-income settings. Development in LMICs is a crucial factor for VAD, with a disproportionately higher burden in low SDI regions.
REGISTRATION
This study protocol was registered with PROSPERO, CRD42020220654.
Topics: Adolescent; Child; Humans; Vitamin A Deficiency; Developing Countries; Prevalence; Public Health; Poverty
PubMed: 37565390
DOI: 10.7189/jogh.13.04084 -
International Journal of Surgery... Dec 2023To estimate the prevalence and associated factors of vitamin D deficiency (VDD) after Roux-en-Y gastric bypass (RYGB). (Meta-Analysis)
Meta-Analysis
OBJECTS
To estimate the prevalence and associated factors of vitamin D deficiency (VDD) after Roux-en-Y gastric bypass (RYGB).
METHODS
PubMed, EMBASE, and CENTRAL were searched for relevant records from inception to 17 March 2023, using search terms: vitamin D, vitamin D3, vitamin D deficiency, hypovitaminosis D, gastric bypass, and RYGB. Studies were eligible for inclusion if they provided related data on VDD prevalence after RYGB.
RESULTS
Of the 1119 screened studies, 72 studies involving 7688 individuals were enrolled in the final analysis. The prevalence estimates of VDD after RYGB were 42%. Subgroup analyses suggested the pooled prevalence of postoperative VDD was 35% for follow-up duration less than or equal to 1 year, 43% for greater than 1 and less than or equal to 5 years, and 54% for greater than 5 years. Meta-regression showed that VDD prevalence was positively correlated with follow-up time. Also, the prevalence was higher in studies with inadequate vitamin D supplementation than in those with adequate supplementation and in Asia population than in those from South America, Europe, and North America. Other factors associated with high VDD prevalence after RYGB included high presurgical VDD prevalence, noncompliant patients, and black populations. No significant association existed between VDD and alimentary length.
CONCLUSION
VDD presented a high prevalence in patients following RYGB. It occurred more frequently with longer postoperative follow-up time. Population-specific vitamin D supplementation measures, targeted treatment for presurgical VDD, improved patient compliance, and periodical follow-ups were necessary to reduce VDD and other adverse outcomes.
Topics: Humans; Gastric Bypass; Prevalence; Vitamin D Deficiency; Vitamin D; Vitamins; Obesity, Morbid
PubMed: 37738003
DOI: 10.1097/JS9.0000000000000732 -
Nutrition and Health Dec 2018The prevalence of vitamin D deficiency in the Iranian community is very high. Women and older people are at the higher risk of vitamin D deficiency. (Meta-Analysis)
Meta-Analysis
BACKGROUND
The prevalence of vitamin D deficiency in the Iranian community is very high. Women and older people are at the higher risk of vitamin D deficiency.
AIM
This study aimed to estimate the prevalence of vitamin D deficiency in Iran by combining the results of various studies.
METHODS
This was a systematic review and meta-analysis. Separate strategies were developed for search in national databases (Irandoc, Magiran, SID) and international databases (Web of Science, PubMed, and Scopus) using the keywords of "vitamin D deficiency," "Iran," and "prevalence." The titles and abstracts of the articles were screened and related full texts were appraised. Those articles that met inclusion criteria were selected for meta-analysis. The heterogeneity of the articles was assessed via the Chi-square test. They were combined using the random-effect approach. In addition, the groups were categorized and analyzed in terms of age and gender.
RESULTS
Of 639 articles, 30 articles with a sample size of 26,042 people were included for data analysis. The overall prevalence of vitamin D deficiency was reported as 0.56. Subgroup analysis showed that 0.64 of women and 0.44 of men were suffering from vitamin D deficiency. The prevalence of vitamin D deficiency in the age groups under 20, 20-50, and over 50 years was 0.56.4, 0.72.4, and 0.59.8, respectively.
CONCLUSIONS
The Iranian Ministry of Health is expected to design strategies to improve the status of vitamin D at the national level.
Topics: Humans; Iran; Prevalence; Vitamin D Deficiency
PubMed: 30296903
DOI: 10.1177/0260106018802968