Clinical practice guidelines for vitamin D in the United Arab Emirates

Knowledge and Predictors of Vitamin D Awareness Among Greek Women: A Cross-Sectional Study

BACKGROUND

Vitamin D plays a crucial role in bone health, calcium absorption, and immune function, yet significant misconceptions and knowledge gaps persist. This study aimed to assess knowledge regarding vitamin D among Greek women and identify factors associated with vitamin D knowledge.

METHODS

A cross-sectional study was conducted among 761 Greek women (mean age: 41.2 ± 7.7 years) using an online self-administered questionnaire designed in Google Forms. Participants were recruited via social media platforms to ensure a geographically diverse sample.

RESULTS

Overall, 57.4% of participants demonstrated knowledge of vitamin D's functions, primarily linking it to bone health (34.4%) and immune function (26.8%). The multiple regression model identified significant predictors of knowledge of vitamin D's functions, including age (OR = 1.041, 95% CI: 1.019-1.062, p < 0.001), weight (OR = 0.964, 95% CI: 0.938-0.992, p = 0.010), and frequent vitamin D testing (>2 times: OR = 2.280, 95% CI: 1.392-3.736, p = 0.001; once-twice: OR = 1.776, 95% CI: 1.111-2.829, p = 0.016). Furthermore, age (OR = 1.054, 95% CI: 1.027-1.081, p < 0.001), weight (OR = 0.987, 95% CI: 0.975-0.999, p = 0.028), higher city population (>50,000 citizens: OR = 1.598, 95% CI: 1.021-2.502, p = 0.040), frequent vitamin D testing (>2 times: OR = 2.616, 95% CI: 1.529-4.447, p < 0.003; one-two times: OR = 1.773, 95% CI: 1.052-2.989, p = 0.032), and children's supplementation (OR = 1.414, 95% CI: 1.007-1.987, p = 0.046) were significant predictors of knowledge regarding diseases preventable by vitamin D.

CONCLUSIONS

Greek women demonstrated moderate awareness of vitamin D's functions, but significant knowledge gaps persist, particularly regarding its role in calcium absorption and dietary sources. Age, frequent vitamin D testing, and urban residence were significant predictors of knowledge. Targeted public health campaigns are essential to address misconceptions and improve vitamin D awareness and practices.

Enhancing the Design of Nutrient Clinical Trials for Disease Prevention-A Focus on Vitamin D: A Systematic Review

OBJECTIVES

This systematic review (SR) highlights principles for nutrient clinical trials and explore the diverse physiological functions of vitamin D beyond its traditional role in the musculoskeletal system related to clinical study designs.

BACKGROUND

Thousands of published research articles have investigated the benefits of vitamin D (a nutrient example taken in this SR) beyond the musculoskeletal system, including the immune, pulmonary, and cardiovascular systems; pregnancy; autoimmune disorders; and cancer. They illustrated vitamin D's molecular mechanisms, interactions, and genomic and nongenomic actions.

METHODS

This SR was designed to identify shortcomings in clinical study designs, statistical methods, and data interpretation that led to inconsistent findings in vitamin D-related publications. SR also highlights examples and insights into avoiding study design errors in future clinical studies, including randomized controlled clinical trials (RCTs). The SR adheres to the latest PRISMA statement, guidelines, and the PICOS process.

RESULTS

Inappropriate or flawed study designs were frequent in clinical trials. Major failures discussed here include too short clinical study duration, inadequate or infrequent doses, insufficient statistical power, failure to measure baseline and achieved levels, and recruiting vitamin D-sufficient participants. These design errors have led to misleading interpretations. Thus, conclusions from such studies should not be generalized or used in guidelines, recommendations, or policymaking.

CONCLUSION

Adequately powered epidemiological studies and RCTs with sufficient vitamin D and duration in individuals with vitamin D deficiency reported favorable clinical outcomes, enriching the literature, enabling to understand its physiology and mechanisms. Proper study designs with rigorous methodologies and cautious interpretation of outcomes are crucial in advancing the nutrient field. The principles discussed apply not only to vitamin D, but also other micro-nutrients and nutraceutical research. Adhering to them enhances the credibility and reliability of clinical trials, SRs, and meta-analysis outcomes. The study emphasizes the importance of focused, hypothesis-driven, well-designed, statistically powered RCTs to explore the diverse benefits of nutrients, conducted in index nutrient deficient participants, and avoidance of study design errors. Findings from such studies should be incorporated into clinical practice, policymaking, and public health guidelines, improving the health of the nation and reducing healthcare costs.

Integrating Endocrine, Genomic, and Extra-Skeletal Benefits of Vitamin D into National and Regional Clinical Guidelines

BACKGROUND/OBJECTIVES

Vitamin D is essential for bone health, immune function, and overall well-being. Numerous ecological, observational, and prospective studies, including randomized controlled clinical trials (RCTs), report an inverse association between higher serum 25-hydroxyvitamin D [25(OH)D; calcifediol] levels in various conditions, including cardiovascular disease, metabolic disorders such as diabetes and obesity, susceptibility to infection-related complications, autoimmune diseases, and all-cause mortality.

RESULTS

Vitamin D operates through two distinct systems. The endocrine system comprises the renal tubular cell-derived circulatory calcitriol, which primarily regulates calcium homeostasis and muscular functions. In contrast, intracellularly generated calcitriol in peripheral target cells is responsible for intracrine/paracrine system signaling and calcitriol-vitamin D receptor-mediated genomic effects. Government-appointed committees and health organizations have developed various clinical practice guidelines for vitamin D supplementation and management. However, these guidelines heavily relied on the 2011 Institute of Medicine (IoM) report, which focused solely on the skeletal effects of vitamin D, ignoring other body systems. Thus, they do not represent maintaining good overall health and aspects of disease prevention. Additionally, the IoM report was intended as a public health recommendation for the government and is not a clinical guideline.

DISCUSSION

New country- and regional-specific guidelines must focus on healthy nations through disease prevention and reducing healthcare costs. They should not be restricted to bone effect and must encompass all extra-skeletal benefits. Nevertheless, due to misunderstandings, medical societies and other governments have used faulty IoM report as a foundation for creating vitamin D guidelines. Consequently, they placed disproportionate emphasis on bone health while largely overlooking its benefits for other bodily systems, making current guidelines, including 2024, the Endocrine Society less applicable to the public. As a result, the utility of published guidelines has been significantly reduced for clinical practice and RCTs that designed on bone-centric are generate misleading information and remain suboptimal for public health and disease prevention.

CONCLUSIONS

This review and its recommendations address the gaps in current vitamin D clinical practice guidelines and propose a framework for developing more effective, country and region-specific recommendations that capture the extra-skeletal benefits of vitamin D to prevent multiple diseases and enhance public health.

Assessment of the quality and content of clinical practice guidelines for vitamin D and for immigrants using the AGREE II instrument: global systematic review

BACKGROUND

Worldwide, more immigrants experience vitamin D (vitD) deficiency than non-immigrants. Recommendations in current clinical practice guidelines (CPGs) concerning vitD are inadequate to address vitD deficiency among immigrants, and there are concerns regarding the quality of guidance in these CPGs.

OBJECTIVES

This study aimed to identify and evaluate the quality of published CPGs addressing vitD and immigrants' health using the Appraisal of Guidelines for Research and Evaluation-II (AGREE II) tool and clarify the recommendations pertaining to vitD and immigrant populations in these CPGs.

METHODS

We performed a systematic search to identify the most recent CPGs across various databases (Ovid MEDLINE ALL, Embase and Turning Research Into Practice), guideline repositories and grey literature. Two reviewers independently conducted study selection and data abstraction and evaluated the quality of the included guidelines using the AGREE II tool.

RESULTS

We identified 25 relevant CPGs; 21 focused on vitD and 4 covered immigrants' health. Around one-quarter of the included CPGs were high quality (≥60% in at least four of the six domains, including 'rigour of development'). The highest mean scores among the six AGREE II domains were for 'clarity of presentation' and 'scope and purpose'. About 4.8% (1/21) of the CPGs on vitD had immigrant-related recommendations. VitD recommendations were emphasised in one out of the four immigrant health CPGs (25%). CPGs covering immigrants' health and vitD were inadequately systematically appraised. Moreover, recommendations regarding vitD were insufficient to address the growing epidemic of vitD deficiency among immigrant populations.

CONCLUSION

The insufficient recommendations for vitD fail to address the rising vitD deficiency among immigrants, highlighting a critical gap in healthcare provisions. Urgent national and international efforts are needed to develop comprehensive CPGs, bridging research, policy and practice disparities. Future guidelines must prioritise routine vitD screening, supplementation protocols for vulnerable immigrant groups, and culturally appropriate interventions to improve health outcomes for immigrants globally.

PROSPERO REGISTRATION NUMBER

CRD42021240562.

Role of vitamin D in COVID-19 and other viral infections

Vitamin D is a steroid hormone that is naturally produced in the body or obtained through dietary sources, primarily under the influence of UVB radiation. This essential nutrient has a vital role in numerous physiological processes, encompassing immune function, cell growth, differentiation, insulin regulation, and cardiovascular well-being, along with its pivotal role in sustaining the delicate equilibrium of calcium and phosphate concentrations in the body. Moreover, vitamin D reinforces mucosal defense and bolsters the immune system through immunomodulation, making it a critical component of overall health. Numerous studies have unveiled the profound connection between vitamin D and the predisposition to respiratory tract infections, including well-known viruses such as influenza and the novel severe acute respiratory syndrome coronavirus 2. Vitamin D deficiency has been consistently linked to increased severity of coronavirus disease 2019 (COVID-19) and a heightened risk of mortality among afflicted individuals. Retrospective observational studies have further substantiated these findings, indicating that levels of vitamin D are linked with both the occurrence and severity of COVID-19 cases. Vitamin D has its influence on viral infections through a multitude of mechanisms, such as promoting the release of antimicrobial peptides and fine-tuning the responses of the immune system. Additionally, vitamin D is intertwined with the intricate network of the renin-angiotensin system, suggesting a potential impact on the development of complications related to COVID-19. While further clinical trials and extensive research are warranted, the existing body of evidence strongly hints at the possible use of vitamin D as a valuable tool in the prophylaxis and management of COVID-19 and other viral infectious diseases.

Association Among Vitamin D Supplementation, Serum 25(OH)D Concentrations, and Mortality Risk: A Prospective Cohort Study Using NHANES 2007-2018 Data

BACKGROUND

To determine the associations among self-reported vitamin D (VD) supplementation, measured serum 25-hydroxyvitamin D (25[OH]D) concentrations, and all-cause and cause-specific mortality risks.

METHODS

Self-reported VD supplementation, serum 25(OH)D concentration, and all-cause and cause-specific mortality data from the National Health and Nutrition Examination Survey 2007-2018 were examined for 10,793 adults ≥20 years from the United States. VD dosage was categorized as <800 or ≥800 IU/d. The mortality status and causes of mortality up to 2019 were determined using the National Death Index. The relationships among VD, 25(OH)D levels, and mortality were analyzed using Cox regression before and after propensity score matching (PSM).

RESULTS

Over a median of 6.6 years, 915 deaths were recorded, 230 because of cardiovascular disease (CVD), 240 because of cancer, and 445 because of other specific causes. Mortality risk did not differ between VD <800 IU/d and ≥800 IU/d before or after PSM. However, serum 25(OH)D concentrations were statistically different before and after PSM. The upper 2 quartiles of 25(OH)D levels were associated with lower all-cause mortality, and the fourth quartile was associated with reduced other-specific mortality before and after PSM. No correlation was found between the 25(OH)D concentration and CVD- or cancer-specific mortality after PSM. The inverse 25(OH)D-mortality relationship was consistent across subgroups.

CONCLUSIONS

Based on this large cohort study, higher 25(OH)D levels are robustly associated with reduced all-cause and other specific mortality but not CVD- or cancer-specific mortality. These findings support the benefits of maintaining adequate VD status for longevity. Further research is required to elucidate these mechanisms and define the optimal VD concentration to reduce mortality. These results underscore the importance of public health strategies for preventing VD deficiency.

Physiology of Vitamin D-Focusing on Disease Prevention

Vitamin D is a crucial micronutrient, critical to human health, and influences many physiological processes. Oral and skin-derived vitamin D is hydroxylated to form calcifediol (25(OH)D) in the liver, then to 1,25(OH)2D (calcitriol) in the kidney. Alongside the parathyroid hormone, calcitriol regulates neuro-musculoskeletal activities by tightly controlling blood-ionized calcium concentrations through intestinal calcium absorption, renal tubular reabsorption, and skeletal mineralization. Beyond its classical roles, evidence underscores the impact of vitamin D on the prevention and reduction of the severity of diverse conditions such as cardiovascular and metabolic diseases, autoimmune disorders, infection, and cancer. Peripheral target cells, like immune cells, obtain vitamin D and 25(OH)D through concentration-dependent diffusion from the circulation. Calcitriol is synthesized intracellularly in these cells from these precursors, which is crucial for their protective physiological actions. Its deficiency exacerbates inflammation, oxidative stress, and increased susceptibility to metabolic disorders and infections; deficiency also causes premature deaths. Thus, maintaining optimal serum levels above 40 ng/mL is vital for health and disease prevention. However, achieving it requires several times more than the government's recommended vitamin D doses. Despite extensive published research, recommended daily intake and therapeutic serum 25(OH)D concentrations have lagged and are outdated, preventing people from benefiting. Evidence suggests that maintaining the 25(OH)D concentrations above 40 ng/mL with a range of 40-80 ng/mL in the population is optimal for disease prevention and reducing morbidities and mortality without adverse effects. The recommendation for individuals is to maintain serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) for optimal clinical outcomes. Insights from metabolomics, transcriptomics, and epigenetics offer promise for better clinical outcomes from vitamin D sufficiency. Given its broader positive impact on human health with minimal cost and little adverse effects, proactively integrating vitamin D assessment and supplementation into clinical practice promises significant benefits, including reduced healthcare costs. This review synthesized recent novel findings related to the physiology of vitamin D that have significant implications for disease prevention.

Assessment the awareness of vitamin D deficiency among the general population in Syria: an online cross-sectional study

BACKGROUND

Vitamin D deficiency is an importance preventable problem in the global and associates with lack levels of awareness about vitamin D. According to prior studies, in the Arab world, there is low of knowledge and awareness toward vitamin D deficiency. The target of our study is evaluating the knowledge level about vitamin D deficiency and determining the associated factors with levels of awareness of its.

METHOD

This online cross-sectional study was performed in Syria between 25 February to 29 March 2023 to assess the levels of knowledge about vitamin D deficiency among general Syrian population. The study's survey was obtained from previously published research and we conducted a pilot study to assure the validity and clarity questionnaire. All Syrian individuals aged 18 or older who were able to read and write and willing to participate were included, while, non-Syrian nationality individuals and all medical staff (doctors, nurses, and medical students…), as well, those under 18 age were excluded. The questionnaire consisted of 23 questions separated into four categories. The first section was sociodemographic information of the study population. The second section measured the level awareness of the study population regarding the benefits of vitamin D. In addition, the third and fourth part evaluated knowing of the respondents about sources of and toxicity consequences of vitamin D. The data were analyzed by utilizing multivariate logistic regression in IBM, SPSS V.28 version.

RESULTS

Overall, 3172 of the study population accepted to participate in this research and 57.9% the majority of them were aged in the range among 18 and 28. While, the average age of the respondents were 30.80 ± 11.957. Regarding with the awareness toward knowledge of advantages and source of vitamin D and outcomes of vitamin D toxicity. Most of the participants mentioned that vitamin D is used to treat bone disease and rickets and contributes in maintaining calcium and phosphates (91.4% and 84.6%, respectively). Whereas, more than half of them reported that sun exposure does not cause vitamin D poisoning and that vegetarians are more likelihood to have vitamin D than non-vegetarians, (54.1% and 54.9%, respectively). Only, age and occupation out of nine predictors variables were significantly correlated with adequate knowledge of Vitamin D (p-value < 0.05). The respondents aged more than 60 years were high probability to have good recognition of Vitamin D than participants aged between 18 and 28 years. (OR = 7.95). Retired participants have shown lower aware of Vitamin D 0.38 times than students.

CONCLUSION

Our research revealed that most of the participated individuals have sufficient comprehension about vitamin D, despite, there were significant gap. Health education via programs by government health-care agencies, NGOs and social workers is necessary to increase the awareness and knowledge toward benefits, source, deficiency and toxicity of vitamin D to avoid injury several diseases such as rickets.

No evidence of a causal relationship between miscarriage and 25-hydroxyvitamin D: a Mendelian randomization study

STUDY QUESTION

Is there a causal relationship between 25-hydroxyvitamin D (25OHD) and miscarriage?

SUMMARY ANSWER

In this study, little evidence of a causal relationship was found between low serum 25OHD concentration or vitamin D deficiency and the risk of miscarriages.

WHAT IS KNOWN ALREADY

Associations between low vitamin D levels and increased risk of miscarriage have been reported, but causality is unclear.

STUDY DESIGN SIZE DURATION

The latest and largest genome-wide association studies (GWAS) for serum 25OHD concentration (n = 417 580), vitamin D deficiency (426 cases and 354 812 controls), miscarriage (16 906 cases and 149 622 controls), and the number of miscarriages (n = 78 700) were used to explore the causal association between serum vitamin D levels and miscarriage by two-sample Mendelian randomization analysis.

PARTICIPANTS/MATERIALS SETTING METHODS

This study was based on summary GWAS results from the FinnGen database and the UK Biobank. The random-effect inverse-variance weighted method was regarded as the primary analysis; MR-Egger, weighted median, weighted mode, simple mode, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were further employed as complementary methods. MR-Egger intercept analysis and MR-PRESSO were employed to test pleiotropy, and Cochran's Q statistic and leave-one-out sensitivity analysis were used to determine the heterogeneity and robustness of the overall estimates, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

There was insufficient evidence of causal associations between serum 25OHD concentration and miscarriage (odds ratio (OR) = 0.995, 95% CI: 0.888 to 1.114, P = 0.927), or the number of miscarriages (β = -0.004, 95% CI: -0.040 to 0.032, P = 0.829). Furthermore, little evidence of causality between genetically determined vitamin D deficiency to miscarriage (OR = 0.993, 95% CI: 0.966 to 1.021, P = 0.624), or the number of miscarriages (β = 0.001, 95% CI: -0.009 to 0.011, P = 0.828), was observed. The results of the sensitivity analysis were robust, and no significant heterogeneity or horizontal pleiotropy was found.

LIMITATIONS REASONS FOR CAUTION

This study is limited by the absence of female-specific GWAS data and the limited amount of GWAS data available for this study, as well as the need for caution in generalizing the findings to non-European ethnic groups.

WIDER IMPLICATIONS OF THE FINDINGS

These findings enhance the current understanding of the intricate association between vitamin D and pregnancy outcomes, challenging prevailing beliefs regarding the strong association with miscarriage. The results provide a special perspective that may prompt further exploration and potentially offer insights for guiding future research and informing clinical guidelines pertaining to the management of miscarriage.

STUDY FUNDING/COMPETING INTERESTS

This project was supported by the Hubei Provincial Natural Science Foundation Program General Surface Project (2022CFB200), the Key Research & Developmental Program of of Hubei Province (2022BCA042), the Fundamental Research Funds for the Central Universities (2042022gf0007, 2042022kf1210), and the Interdisciplinary Innovative Talents Foundation from Renmin Hospital of Wuhan University (JCRCWL-2022-001, JCRCYG-2022-009). All authors have no conflicts of interest to declare.

TRIAL REGISTRATION NUMBER

N/A.

Nutrition guidelines for preterm infants: A systematic review

BACKGROUND

There is no consensus on optimal nutrition for preterm infants, leading to substantial practice variation. We aimed to assess the quality of nutrition guidelines for preterm infants, the consistency of recommendations, and the gaps in recommendations.

METHODS

We searched databases and websites for nutrition guidelines for preterm infants before first hospital discharge, which were endorsed, prepared, or authorized by a regional, national, or international body, written in English, and published between 2012 and 2023. Two reviewers independently screened articles and extracted the recommendations. Four reviewers appraised the included guidelines using Appraisal of Guidelines, Research, and Evaluation II.

RESULTS

A total of 7051 were identified, with 27 guidelines included, 26% of which were high in quality. Most guidelines lacked stakeholder involvement and rigor of development. We found considerable variation in recommendations, many of which lacked details on certainty of evidence and strength of recommendation. Recommendations for type of feed and breastmilk fortification were consistent among high-quality guidelines, but recommendations varied for intakes of almost all nutrients and monitoring of nutrition adequacy. Different guidelines gave different certainty of evidence for the same recommendations. Most gaps in recommendations were due to very low certainty of evidence.

CONCLUSION

Future development of nutrition guidelines for preterm infants should follow the standard guideline development method and ensure the rigorous process, including stakeholders' involvement, to improve the reporting of strength of recommendation, certainty of evidence, and gaps in recommendation. Evidence is needed to support recommendations about macro and micronutrient intakes, breastmilk fortification, and markers on adequacy of intake of different nutrients.

Prevalence of type 2 diabetes (T2D) in Lebanon: association with inflammatory and infectious clinical markers

BACKGROUND

Diabetes is a growing health concern in the Middle East, particularly in countries with high rates of obesity and unhealthy lifestyles. Therefore, this study aimed to determine the prevalence of type 2 diabetes (T2D) in Lebanon and its association with clinical markers of inflammation and infection.

METHODS

This cross-sectional study examined retrospectively the medical laboratory record of 4093 patients from all Lebanese regions. Prevalence of T2D and its association with age, gender, calcium, vitamin D (VitD), neutrophils-to-lymphocytes ratio (NLR), and C-reactive protein (CRP) were determined. The prevalence of infection in a subpopulation of 712 patients tested from blood, body fluid, sputum, swab, tissue, and urine samples and its etiology was also assessed.

RESULTS

Overall, 17% (n = 690) of our participants had T2D, and the mean HbA1c was 5.9% ± 1.2. Age, gender, triglycerides, NLR, and calcemia were significantly associated with T2D. The prevalence of infections in a subgroup of 712 patients was 11.1% (n = 79). Urinary tract infections (UTIs) caused by Escherichia coli (E. coli) were the most common cause of infection, with the highest prevalence in the pre-diabetic group. Serum CRP level was significantly higher in the diabetic group than the pre-diabetic and control groups. Diabetic patients also presented a significantly higher percentage of NLR > 3 compared to the pre-diabetic and control groups.

CONCLUSION

The prevalence of T2D is increasing in the Lebanese population compared to prior reports. These results should be considered to guide effective public health preventive strategies.

Infections and Autoimmunity-The Immune System and Vitamin D: A Systematic Review

Both 25-autoimmunity and(25(OH)D: calcifediol) and its active form, 1,25-dihydroxyvitamin D (1,25(OH)2D: calcitriol), play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. This systematic review examines vitamin D's mechanisms and effects on enhancing innate and acquired immunity against microbes and preventing autoimmunity. The study evaluated the quality of evidence regarding biology, physiology, and aspects of human health on vitamin D related to infections and autoimmunity in peer-reviewed journal articles published in English. The search and analyses followed PRISMA guidelines. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. Most adequately powered, well-designed, randomized controlled trials with sufficient duration supported substantial benefits of vitamin D. Virtually all studies that failed to conclude benefits or were ambiguous had major study design errors. Treatment of vitamin D deficiency costs less than 0.01% of the cost of investigation of worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21-most had severe vitamin D deficiency. Yet, the lack of direction from health agencies and insurance companies on using vitamin D as an adjunct therapy is astonishing. Data confirmed that keeping an individual's serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks, sepsis, and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5000 and 8000 IU vitamin D supplements daily (average dose, for non-obese adults, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase the catabolism of vitamin D and a few other specific disorders require much higher intake. This systematic review evaluates non-classical actions of vitamin D, with particular emphasis on infection and autoimmunity related to the immune system.

Omega-3 polyunsaturated fatty acids and/or vitamin D in autism spectrum disorders: a systematic review

This systematic review aims to offer an updated understanding of the relationship between omega-3 supplementation and/or vitamin D and autism spectrum disorders (ASD). The databases PubMed, Cochrane Library, Web of Science, EMBASE, CINAHL, Vip, CNKI, Wanfang, China Biomedical Database databases were searched using keywords, and relevant literature was hand-searched. Papers (n = 1,151) were systematically screened and deemed eligible since 2002. Twenty clinical controlled studies were included in the final review. The findings were analyzed for intervention effects focusing on the core symptoms of ASD, included social functioning, behavioral functioning, speech function and biomarkers changes. The review found that the effects of omega-3 supplementation on ASD were too weak to conclude that core symptoms were alleviated. Vitamin D supplementation improved core symptoms, particularly behavioral functioning, however, the results of the literatures included in this study were slightly mixed, we cannot directly conclude that vitamin D supplementation has a beneficial effect on a specific symptom of ASD, but the overall conclusion is that vitamin D supplementation has a positive effect on behavioral functioning in ASD. Omega-3 and vitamin D combination supplementation has a good combined effect on social and behavioral outcomes in patients with ASD.

Vitamin D deficiency increases with age and adiposity in Emirati children and adolescents irrespective of type 1 diabetes mellitus: a case control study

BACKGROUND

Association of vitamin D (25(OH)D) deficiency with obesity and diabetes has been well-established in paediatric and adult populations. This study aims to report the association of 25(OH)D deficiency with body composition and prevalence of 25(OH)D deficiency in Emirati children and adolescents, who attended a diabetes centre in the United Arab Emirates.

METHODS

Using Abu Dhabi Diabetes and Obesity Study cohort, type 1 diabetes (T1D) and normoglycaemic (NG) participants between 4-19 years of age were selected. WHO criteria were used to define 25(OH)D cut-offs: deficient (< 30 nmol/L), insufficient (30-50 nmol/L) and sufficient (> 50 nmol/L). Based on CDC recommendations, BMI percentile was categorised as underweight, normal weight, overweight and obesity.

RESULTS

After age and sex matching, 148 T1D cases and 296 NG controls were identified. 25(OH)D deficiency was observed in 22.3% (n = 33) T1D and 40.5% (n = 120) NG participants. 25(OH)D levels were lower in adolescents (15 - 19 years) than children (4 - 7 years) in both T1D and NG groups (p = 0.018 vs p < 0.001). Females were more likely to be 25(OH)D deficient in both groups. Children and adolescents with BMI ≥ 95^th percentile were more likely to be 25(OH)D deficient than those with normal weight (OR: 2.69; 95% CI: 1.56, 4.64). Adiposity measures and 25(OH)D levels correlated negatively in both groups (T1D p < 0.01, NG p < 0.001).

CONCLUSION

Vitamin D 25(OH)D deficiency is notably prevalent in Emirati children and adolescents despite adequate sunlight throughout the year. The prevalence was lower in those with T1D which may be indicative of treatment compliance in this population. This study also confirms important negative association of serum 25(OH)D levels with body mass and obesity in this population.

Periodontal Disease and Other Adverse Health Outcomes Share Risk Factors, including Dietary Factors and Vitamin D Status

For nearly a century, researchers have associated periodontal disease (PD) with risks of other adverse health outcomes such as cardiovascular disease, diabetes mellitus, and respiratory diseases, as well as adverse pregnancy outcomes. Those findings have led to the hypothesis that PD causes those adverse health outcomes either by increasing systemic inflammation or by the action of periodontopathic bacteria. However, experiments largely failed to support that hypothesis. Instead, the association is casual, not causal, and is due to shared underlying modifiable risk factors, including smoking, diet, obesity, low levels of physical activity, and low vitamin D status. Diabetes mellitus is also considered a risk factor for PD, whereas red and processed meat are the most important dietary risk factors for diabetes. Because PD generally develops before other adverse health outcomes, a diagnosis of PD can alert patients that they could reduce the risk of adverse health outcomes with lifestyle changes. In addition, type 2 diabetes mellitus can often be reversed rapidly by adopting an anti-inflammatory, nonhyperinsulinemic diet that emphasizes healthful, whole plant-based foods. This review describes the evidence that proinflammatory and prohyperinsulinemia diets and low vitamin D status are important risk factors for PD and other adverse health outcomes. We also make recommendations regarding dietary patterns, food groups, and serum 25-hydroxyvitamin D concentrations. Oral health professionals should routinely inform patients with PD that they could reduce their risk of severe PD as well as the risks of many other adverse health outcomes by making appropriate lifestyle changes.

Physiological Basis for Using Vitamin D to Improve Health

Vitamin D is essential for life-its sufficiency improves metabolism, hormonal release, immune functions, and maintaining health. Vitamin D deficiency increases the vulnerability and severity of type 2 diabetes, metabolic syndrome, cancer, obesity, and infections. The active enzyme that generates vitamin D [calcitriol: 1,25(OH)2D], CYP27B1 (1α-hydoxylase), and its receptors (VDRs) are distributed ubiquitously in cells. Once calcitriol binds with VDRs, the complexes are translocated to the nucleus and interact with responsive elements, up- or down-regulating the expression of over 1200 genes and modulating metabolic and physiological functions. Administration of vitamin D3 or correct metabolites at proper doses and frequency for longer periods would achieve the intended benefits. While various tissues have different thresholds for 25(OH)D concentrations, levels above 50 ng/mL are necessary to mitigate conditions such as infections/sepsis, cancer, and reduce premature deaths. Cholecalciferol (D3) (not its metabolites) should be used to correct vitamin D deficiency and raise serum 25(OH)D to the target concentration. In contrast, calcifediol [25(OH)D] raises serum 25(OH)D concentrations rapidly and is the agent of choice in emergencies such as infections, for those who are in ICUs, and for insufficient hepatic 25-hydroxylase (CYP2R1) activity. In contrast, calcitriol is necessary to maintain serum-ionized calcium concentration in persons with advanced renal failure and hypoparathyroidism. Calcitriol is, however, ineffective in most other conditions, including infections, and as vitamin D replacement therapy. Considering the high costs and higher incidence of adverse effects due to narrow therapeutic margins (ED50), 1α-vitamin D analogs, such as 1α-(OH)D and 1,25(OH)2D, should not be used for other conditions. Calcifediol analogs cost 20 times more than D3-thus, they are not indicated as a routine vitamin D supplement for hypovitaminosis D, osteoporosis, or renal failure. Healthcare workers should resist accepting inappropriate promotions, such as calcifediol for chronic renal failure and calcitriol for osteoporosis or infections-there is no physiological rationale for doing so. Maintaining the population's vitamin D sufficiency (above 40 ng/mL) with vitamin D3 supplements and/or daily sun exposure is the most cost-effective way to reduce chronic diseases and sepsis, overcome viral epidemics and pandemics, and reduce healthcare costs. Furthermore, vitamin D sufficiency improves overall health (hence reducing absenteeism), reduces the severity of chronic diseases such as metabolic and cardiovascular diseases and cancer, decreases all-cause mortality, and minimizes infection-related complications such as sepsis and COVID-19-related hospitalizations and deaths. Properly using vitamin D is the most cost-effective way to reduce chronic illnesses and healthcare costs: thus, it should be a part of routine clinical care.

Knowledge about Vitamin D among Women in the United Arab Emirates

Vitamin D deficiency is a significant public health issue as it affects almost 90% of the United Arab Emirates (UAE) population. A bigger portion of this percentage is women due to the physiological changes throughout their life cycle. This study aims to assess the knowledge about vitamin D among women in the UAE. This is a quantitative cross-sectional study. Using snowball sampling, an electronic questionnaire was sent to women aged 18 years and above. Overall, 1537 women completed the questionnaire. The participants had mean scores of 49.4 ± 10.7 and 59.6 ± 14.6 for general and nutritional knowledge, respectively. Factors associated with higher scores included older age, marriage, higher educational level, and having tested their vitamin D levels. Factors associated with lower scores included the history of a chronic illness and being employed. Findings indicate that women in this study showed a low level of vitamin D knowledge specifically regarding the non-skeletal benefits of vitamin D and factors that affect vitamin D synthesis. Therefore, health education and promotion programs must be implemented across the UAE to improve overall awareness about vitamin D.

Quality Appraisal of Nutritional Guidelines to Prevent, Diagnose, and Treat Malnutrition in All Its Forms during Pregnancy

This work aimed to identify clinical practice guidelines (CPGs) that include recommendations for the prevention, diagnosis, and treatment of women’s malnutrition during pregnancy and to evaluate the quality of these guidelines using the Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument. We conducted a literature review using PubMed and different websites from January 2009 to February 2021. The quality of the CPGs was independently assessed by reviewers using the AGREE II instrument, which defines guidelines scoring >70% in the overall assessment as “high quality”. The analysis included 43 guidelines. Among the main findings, we identified that only half of the CPGs (51.1%) obtained a final “high quality” evaluation. AGREE II results varied widely across domains and categories. The two domains that obtained the highest scores were scope and purpose with 88.3% (range 39 to 100%) and clarity of presentation with 87.2% (range 25 to 100%). Among the “high quality” CPGs, the best scores were achieved by the three guidelines published by the National Institute of Health and Care Excellence (NICE) and the World Health Organization (WHO). Due to the importance of maternal nutrition in pregnancy, it is essential to join forces to improve the quality of the guidelines, especially in CPGs that do not meet the reference standards for quality.

Evaluation of the clinical practice guidelines and consensuses on calcium and vitamin D supplementation in healthy children using the Appraisal of Guidelines for Research and Evaluation II instrument and Reporting Items for Practice Guidelines in Healthcare statement

Background

This study aimed to assess the methodological and reporting quality of the guidelines and consensus on calcium and vitamin D supplementation in healthy children, and the consistency of these recommendations.

Methods

A systematic search of relevant guideline websites and databases, including PubMed, Embase, CNKI, WangFang, and SinoMed, was undertaken from inception to April 7, 2021, by two independent reviewers who assessed the eligible guidelines using the validated Appraisal of Guidelines for Research and Evaluation Instrument II (AGREE II) and the Reporting Items for Practice Guidelines in Healthcare (RIGHT) tools. Overall, the between-reviewer agreement was evaluated using an intra-class correlation coefficient.

Results

A total of 24 guidelines and consensuses from 2002 to 2022 were identified from China, the United States, Canada, France, Australia, New Zealand, Europe, and other countries and regions. These were of mixed quality, and scored poorly in the rigor of development, editorial independence, and applicability of the domains of AGREE II. Among the seven domains of the RIGHT checklist, domain one (basic information) had the highest reporting rate (69.3%), whereas domain five (review and quality assurance) had the lowest reporting rate (11.5%). The overall quality of the included guidelines and consensuses was low. Only 12 guidelines were recommended, with modifications. The recommended calcium intake for children of different ages varies greatly (400–1,150 mg/day). Among the included guidelines and consensuses, a vitamin D (VD) prevention dose of 400 IU/day in infants was generally considered safe, and 25-hydroxyvitamin-D [25(OH)D] levels of <20 ng/mL (50 nmol/L) or 20–30 ng/mL (50–75 nmol/L) indicated VD deficiency or insufficiency. However, the recommended amount of VD for children of different age groups and risk strata differed considerably (400–4,000 IU/day or 10–100 μg/day). The choice of VD2 or VD3 supplements and sunlight exposure also differed across the guidelines and consensuses.

Conclusion

There is considerable variability in calcium and VD guidelines and consensus development methods in calcium and VD supplementation for healthy children. Therefore, efforts are necessary to strengthen the methodological rigor of guideline development and utilize the best available evidence to underpin recommendations.

Breastfeeding and vitamin D

The recent re-emergence of vitamin D deficiency (VDD) and rickets among breastfed infants without adequate sunlight exposure and vitamin D supplementation has been reported worldwide. Breastfed infants are particularly vulnerable to VDD because of the low vitamin D content of breast milk, restricted sunlight exposure, increased pollution, and limited natural dietary sources of vitamin D. The prevalence of VDD in breastfed infants differs vastly between studies and nations at 0.6%-91.1%. The recommended intake of vitamin D for lactating mothers to optimize their overall vitamin D status and, consequently, of their breast milk is 200-2,000 IU/day, indicating a lack of consensus. Some studies have suggested that maternal high-dose vitamin D supplementation (up to 6,400 IU/day) can be used as an alternate strategy to direct infant supplementation. However, concern persists about the safety of maternal high-dose vitamin D supplementation. Direct infant supplementation is the currently available option to support vitamin D status in breastfed infants. The recommended dose for vitamin D supplementation in breastfed infants according to various societies and organizations worldwide is 200-1,200 IU/day. Most international guidelines recommend that exclusively or partially breastfed infants be supplemented with 400 IU/day of vitamin D during their first year of life. However, domestic studies on the status and guidelines for vitamin D in breastfed infants are insufficient. This review summarizes the prevalence of VDD in breastfed infants, vitamin D content of breast milk, and current guidelines for vitamin D supplementation of lactating mothers and infants to prevent VDD in breastfed infants.

Physiologically Based Pharmacokinetic Modeling of Vitamin D3 and Metabolites in Vitamin D-Insufficient Patients

A physiologically based pharmacokinetic (PBPK) model of vitamin D3 and metabolites [25(OH)D3, 1,25(OH)2D3, and 24,25(OH)2D3] is presented. In this study, patients with 25(OH)D3 plasma concentrations below 30 ng/ml were studied after a single dose of 5000 I.U. (125 µg) cholecalciferol, provided with 5000 I.U. daily cholecalciferol supplementation until vitamin D replete [25(OH)D3 plasma concentrations above 30 ng/ml], and had serial plasma samples were collected at each phase for 14 days. Total concentrations of vitamin D3 and metabolites were measured by ultra-high performance liquid chromatography tandem mass spectrometry. A nine-compartment PBPK model was built using MATLAB to represent the triphasic study nature (insufficient, replenishing, and sufficient). The stimulatory and inhibitory effect of 1,25(OH)2D3 were incorporated by fold-changes in the primary metabolic enzymes CYP27B1 and CYP24A1, respectively. Incorporation of dynamic adipose partition coefficients for vitamin D3 and 25(OH)D3 and variable enzymatic reactions aided in model fitting. Measures of model predictions agreed well with data from metabolites, with 97%, 88%, and 98% of the data for 25(OH)D3, 24,25(OH)2D3, and 1,25(OH)2D3, respectively, within twofold of unity (fold error values between 0.5 and 2.0). Bootstrapping was performed and optimized parameters were reported with 95% confidence intervals. This PBPK model could be a useful tool for understanding the connections between vitamin D and its metabolites under a variety of clinical situations. SIGNIFICANCE STATEMENT: This study developed a physiologically based pharmacokinetic (PBPK) model of vitamin D3 and metabolites for patients moving from an insufficient to a repleted state over a period of 16 weeks.

Adjunctive vitamin D therapy in various diseases in children: a scenario according to standard guideline

BACKGROUND

Adherence to standard guidelines is imperative when question comes to disease management. The present study aimed to evaluate the administration of adjunctive vitamin D therapy in various diseases, its adherence to standard guideline and the effect of socioeconomic status on the consumption of vitamin D in children.

METHODS

Cross sectional observational study was conducted among 400 ambulatory pediatric patients at Children's Hospital, Pakistan Institute of Medical Sciences Islamabad, from November 2017 to June 2018. Data were collected by a self-designed structured questionnaire from the patient's medical chart. Adjunctive vitamin D therapy adherence was evaluated by the U. S endocrinology clinical practice guideline of vitamin D deficiency. The association between socioeconomic status and consumption of vitamin D was examined by chi-square. Alpha value (p ≤ 0.005) was considered statistically significant. Statistical analysis was done by SPSS version 25.

RESULTS

In 400 patients, 9 diseases and 21 comorbid conditions were identified, in which adjunctive vitamin D therapy was prescribed. Adherence to vitamin D testing in high-risk vitamin D deficiency diseases as; seizures (3.8%), bone deformities (13.3%), steroid-resistant nephrotic syndrome (0.0%), cerebral palsy (5.9%) and meningitis (14.3%). Adherence to prescribed vitamin D dose was in (41.3%) patients in various diseases. Significant association (p < 0.05) was found between socioeconomic status and consumption of vitamin D in children and mothers.

CONCLUSIONS

It was found that adjunctive vitamin D was being prescribed in various diseases and comorbidities. Overall poor adherence to the standard guideline was observed in disease management in children. Low socioeconomic status affects vitamin D supplementation consumption in children.

Outdoor Activity in the Daytime, but Not the Nighttime, Predicts Better Mental Health Status During the COVID-19 Curfew in the United Arab Emirates

Background

The COVID-19 pandemic and the associated infection prevention and control measures had a negative impact on the mental health of many people. In the United Arab Emirates (UAE), infection control measures implemented after March 24th, 2020, placed necessary restrictions on people's freedom of movement.

Aim

This study aimed to assess the association between levels of daytime vs. nighttime outdoor activity and mental health among a sample of UAE residents during the lockdown period.

Method

An opportunity sample of 245 participants completed an online survey assessing levels of depression, somatic symptoms, daytime and nighttime activity levels.

Results

Multivariate logistic regression revealed that daytime activity, but not nighttime activity, was associated with a lower risk of clinically significant depressive and somatic symptomatology.

Conclusion

The association of better mental health with daytime not nighttime outdoor activity could be possibly attributed to vitamin D, but further studies are needed to confirm this speculation.

Vitamin D Deficiency and Its Associated Factors among Female Migrants in the United Arab Emirates

Vitamin D is important for bone health, and vitamin D deficiency could be linked to noncommunicable diseases, including cardiovascular disease. The purpose of this study was to determine the prevalence of vitamin D deficiency and its associated risk factors among female migrants from Philippines, Arab, and South Asian countries residing in the United Arab Emirates (UAE). We used a cross-sectional study to recruit a random sample (N = 550) of female migrants aged 18 years and over in the city of Al Ain, UAE. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D concentrations ≤20 ng/mL (50 nmol/L). We used multivariable logistic regression analysis to identify risk factors associated with vitamin D deficiency. The mean age of participants was 35 years (SD ± 10). The overall prevalence rate of vitamin D deficiency was 67% (95% CI 60-73%), with the highest rate seen in Arabs (87%), followed by South Asians (83%) and the lowest in Filipinas (15%). Multivariate analyses showed that low physical activity (adjusted odds ratio (aOR) = 4.59; 95% CI 1.98, 10.63), having more than 5 years duration of residence in the UAE (aOR = 4.65; 95% CI: 1.31, 16.53) and being obese (aOR = 3.56; 95% CI 1.04, 12.20) were independently associated with vitamin D deficiency, after controlling for age and nationality. In summary, vitamin D deficiency was highly prevalent among female migrants, especially Arabs and South Asians. It is crucial that health professionals in the UAE become aware of this situation among this vulnerable subpopulation and provide intervention strategies aiming to rectify vitamin D deficiency by focusing more on sun exposure, physical activity, and supplementation.

Vitamin D Supplementation and Fractures in Adults: A Systematic Umbrella Review of Meta-Analyses of Controlled Trials

CONTEXT

The growing number of systematic reviews/meta-analyses (SR/MAs) on vitamin D (± calcium) for fracture prevention has led to contradictory guidelines.

OBJECTIVE

This umbrella review aims to assess the quality and explore the reasons for the discrepancy of SR/MAs of trials on vitamin D supplementation for fracture risk reduction in adults.

METHODS

We searched 4 databases (2010-2020), Epistemonikos, and references of included SRs/MAs, and we contacted experts in the field. We used A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR-2) for quality assessment. We compared results and investigated reasons for discordance using matrices and subgroup analyses (PROSPERO registration: CRD42019129540). We included 13 SR/MAs on vitamin D and calcium (Ca/D) and 19 SR/MAs on vitamin D alone, compared to placebo/control.

RESULTS

Only 2 from 10 SRs/MAs on Ca/D were of moderate quality. Ca/D reduced the risk of hip fractures in 8 of 12 SRs/MAs (relative risk [RR] 0.61-0.84), and any fractures in 7 of 11 SR/MAs (RR 0.74-0.95). No fracture risk reduction was noted in SRs/MAs exclusively evaluating community-dwelling individuals or in those on vitamin D alone compared to placebo/control. Discordance in results between SRs/MAs stems from inclusion of different trials, related to search periods and eligibility criteria, and varying methodology (using intention to treat, per-protocol, or complete case analysis from individual trials).

CONCLUSION

Ca/D reduces the risk of hip and any fractures, possibly driven by findings from institutionalized individuals. Individual participant data meta-analyses of patients on Ca/D with sufficient follow-up periods, and subgroup analyses, would unravel determinants for a beneficial response to supplementation.

Using prior information to enhance microwave tomography images in bone health assessment

BACKGROUND

Osteoporosis is the major cause of bone weakness and fragility in more than 10 million people in the United States. This disease causes bone fractures in the hip or spine, which result in increasing the risk of disabilities or even death. The current gold standard in osteoporosis diagnostics, X-ray, although reliable, it uses ionizing radiations that makes it unfeasible for early and continuous monitoring applications. Recently, microwave tomography (MWT) has been emerging as a biomedical imaging modality that utilizes non-ionizing electromagnetic signals to screen bones' electrical properties. These properties are highly correlated to bones' density, which makes MWT to be an effective and safe alternative for frequent testing in osteoporosis diagnostics.

RESULTS

Both the conventional and wearable simulated systems were successful in localizing the tibia and fibula bones in the enhanced MWT images. Furthermore, structure extraction of the leg's model from the blind MWT images had a minimal error compared to the original one (L2-norm: 15.60%). Under five sequentially incremental bone volume fraction (BVF) scenarios simulating bones' treatment procedure, bones were detected successfully and their densities were found to be inversely proportional to the real part of the relative permittivity values.

CONCLUSIONS

This study paves the way towards implementing a safe and user-friendly MWT system that can be wearable to monitor bone degradation or treatment for osteoporosis cases.

METHODS

An anatomically realistic finite-element (FE) model representing the human leg was initially generated and filled with corresponding tissues' (skin, fat, muscles, and bones) dielectric properties. Then, numerically, the forward and inverse MWT problems were solved within the framework of the finite-element method-contrast source inversion algorithm (FEM-CSI). Furthermore, image reconstruction enhancements were investigated by utilizing prior information about different tissues as an inhomogeneous background as well as by adjusting the imaging domain and antennas locations based on the prior structural information. In addition, the utilization of a medically approved matching medium that can be used in wearable applications, namely an ultrasound gel, was suggested. Additionally, an approach based on k-means clustering was developed to extract the prior structural information from blind reconstructions. Finally, the enhanced images were used to monitor variations in BVF.

Prevalence of Vitamin D Deficiency Between Type 2 Diabetes Mellitus Patients and Non-Diabetics in the Arab Gulf

BACKGROUND

The link between the risk of type 2 diabetes mellitus (T2DM) and vitamin D deficiency has perplexed the medical society due to the controversy in the data available. Saudi Arabia (SA) is a sunny region; however, ample amount of data reported the increased prevalence of vitamin D deficiency along with T2DM. Thus, this study aimed to compare vitamin D deficiency between healthy and T2DM patients in SA, alongside with the risk factors associated with that.

METHODS

A cross-sectional study was conducted in the Medical Unit, Taibah University in Al-Madinah Al-Munawarah, SA, from November 2017 to May 2018. The involved participants were non-diabetics and T2DM men. Measuring vitamin D for T2DM and non-diabetics group was done by trained technicians. Data analysis was done via SPSS.

RESULTS

Sixty-four participants (T2DM group = 32; non-diabetics group = 32) were recruited, and the mean age of T2DM patients was 48.6 ± 10.4, while that of the non-diabetics was 42.4 ± 6.5. The mean of vitamin D level was found higher in the non-diabetic participants than in diabetic patients. There was statistically significant association between vitamin D deficiency and T2DM (P = 0.001). Besides, duration of diabetes was the only factor, found to be positively correlated with vitamin D deficiency in T2DM patients.

CONCLUSION

Early screening for vitamin D serum-level is recommended for T2DM patients in Saudi Arabia. Therefore, early correction of vitamin D levels should be considered, and medical and scientific societies, along with other sectors such as the media, should highlight and increase the awareness of the importance of vitamin D and the seriousness of its deficiency.

Vitamin D recommendations in clinical guidelines: A systematic review, quality evaluation and analysis of potential predictors

BACKGROUND

Vitamin D has been widely promoted for bone health through supplementation and fortification of the general adult population. However, there is growing evidence that does not support these strategies. Our aim is to review the quality and recommendations on vitamin D nutritional and clinical practice guidelines and to explore predictive factors for their direction and strength.

METHODS

We searched three databases and two guideline repositories from 2010 onwards. We performed a descriptive analysis, a quality appraisal using AGREE II scores (Appraisal of Guidelines Research and Evaluation) and a bivariate analysis evaluating the association between direction and strength of recommendations, AGREE II domains' scores and pre-specified characteristics.

RESULTS

We included 34 guidelines, 44.1% recommended, 26.5% suggested and 29.4% did not recommend vitamin D supplementation. Guidelines that scored higher for "editorial independence" and "overall quality score" were less likely to recommend or suggest vitamin D supplementation (median 68.8 vs 35.4; P = .001 and 58.3 vs 37.5; P = .02). Guidance produced by government organisations and those that reported source of funding were associated with higher AGREE II scores. Unclear role of source of funding was associated with recommending or suggesting vitamin D supplementation (P = .034). Editorial independence was an independent predictor for recommending or suggesting vitamin D supplementation (OR 1.09; CI95% 1.02 to 1.16; P = .006).

CONCLUSIONS

Policymakers, clinicians and patients should be aware that lower quality guidelines and those reporting conflicts of interest are more likely to promote vitamin D supplementation. Guideline organisations should improve the quality of their recommendations' development and the management of conflicts of interest. Users and editors should be aware of these findings when using and appraising guidelines.

Vitamin D deficiency is a risk factor for delayed tooth eruption associated with persistent primary tooth

OBJECTIVE

To verify the association between 25(OH)D level and polymorphisms in the vitamin D receptor gene (VDR) with the disturbance in the dental development and eruption.

DESIGN

A total of 183 children from two datasets were evaluated. The first dataset was a case-control (15:15) designed to assess if persistent primary tooth (PPT) is associate with serum 25(OH)D level and with genetic polymorphisms in VDR. The second dataset of genomic DNA samples from 54 children with delayed tooth eruption (DTE) and 99 controls were analysed to verify if genetic polymorphisms in VDR (rs2228570 and rs739837) are associated with DTE. The 25(OH)D and the genotyping/allele distribution were analysed using the T-test and chi-square test, respectively.

RESULTS

The level of 25(OH)D in the PPT group (24.9 ± 6.4 mg/mL) was significantly lower than the control (30.0 ± 7.0 mg/mL) (p=.047). Our data show that children with 25(OH)D deficiency are more likely to present PPT (OR = 2.36; 95%CI: 1.51, 3.70). The rs739837 and rs2228570 polymorphisms were not associated with DTE (OR = 1.44; 95%CI: 0.87, 2.39 and OR = 0.80; 95%CI: 0.45, 1.44, respectively).

CONCLUSIONS

Vitamin D deficiency is a risk factor for PPT.

Monitoring Bone Density Using Microwave Tomography of Human Legs: A Numerical Feasibility Study

A major cause of bone mass loss worldwide is osteoporosis. X-ray is considered to be the gold-standard technique to diagnose this disease. However, there is currently a need for an alternative modality due to the ionizing radiations used in X-rays. In this vein, we conducted a numerical study herein to investigate the feasibility of using microwave tomography (MWT) to detect bone density variations that are correlated to variations in the complex relative permittivity within the reconstructed images. This study was performed using an in-house finite-element method contrast source inversion algorithm (FEM-CSI). Three anatomically-realistic human leg models based on magnetic resonance imaging reconstructions were created. Each model represents a leg with a distinct fat layer thickness; thus, the three models are for legs with thin, medium, and thick fat layers. In addition to using conventional matching media in the numerical study, the use of commercially available and cheap ultrasound gel was evaluated prior to bone image analysis. The inversion algorithm successfully localized bones in the thin and medium fat scenarios. In addition, bone volume variations were found to be inversely proportional to their relative permittivity in the reconstructed images with the root mean square error as low as 2.54. The observations found in this study suggest MWT as a promising bone imaging modality owing to its safe and non-ionizing radiations used in imaging objects with high quality.

Sex-Dependent Association of Vitamin D With Insulin Resistance in Humans

BACKGROUND

Animal studies suggested that vitamin D might decrease insulin resistance. Estrogen increased insulin sensitivity and glucose tolerance in rodents. However, sex-specific association of vitamin D with insulin resistance in humans remains unclear.

OBJECTIVES

To investigate the sex-dependency of the association of insulin resistance and 25-hydroxyvitamin D [25(OH)D] in a large Caucasian population.

METHODS

Cross-sectional study from out-patients' blood samples with measurements of 25(OH)D and homeostatic model assessment of insulin resistance (HOMA-IR) drawn at exactly the same day (n = 1887). This cohort was divided into 3 groups: (1) group with vitamin D deficiency (n = 1190), (2) group with vitamin D sufficiency (n = 686), and (3) vitamin D excess groups (n = 11); the vitamin D excess group was excluded from further analysis due to the small size.

RESULTS

Analysis of the entire study population showed that serum 25(OH)D was inversely associated with HOMA-IR [Spearman correlation coefficient (rs) = -0.19, P < 0.0001]. When considering the vitamin D status, this association was only seen in the vitamin D deficiency group but not in the vitamin D sufficient group. The correlation was sex-dependent: HOMA-IR was inversely correlated with vitamin D in women with vitamin D deficiency (rs = -0.26, P < 0.0001) but not in men with vitamin D deficiency (rs = 0.01, P = 0.714). After multivariate linear regression analysis considering confounding factors, this relationship was again only seen in women.

CONCLUSION

Vitamin D was inversely and independently associated with insulin resistance only in women with vitamin D deficiency. Based on our data, we suggest that in particular vitamin D deficient women might benefit from vitamin D substitution by improving insulin resistance. This, however, needs to be proven in adequately designed double-blind placebo-controlled clinical studies.

The Significance of Measuring Vitamin D Serum Levels in Women with Uterine Fibroids

Uterine fibroids (UFs) are benign tumors originating from smooth muscle cells and are considered a common pathology that affects numerous women which is a notable socio-economic problem. Several UF risk factors have been identified including black race, obesity, and vitamin D deficiency. Vitamin D is steroid compound with pleiotropic effects on the human body. Vitamin D deficiency is a major public health concern worldwide. Several studies have shown that the majority of UF patients experienced hypovitaminosis D. In addition, sufficient vitamin D serum levels are associated with the reduced risk of UFs. In this review, we present available data highlighting the importance of measuring vitamin D serum levels in women with UFs and women at a high risk for UF development. We proposed a preliminary clinical instruction of 25-hydroxyvitamin D measurements and vitamin D supplementation for clinicians who are involved in the treatment of patients with UFs. Achieving sufficient serum levels of vitamin D might be of interest in patients with UFs. Screening, supplementation, treatment guidelines, and public health strategies for vitamin D deficiency in women with UFs as well as women at a high risk of UF development might be of potential importance as well.

Can Vitamin D Therapy Contribute to the Conservative Resolution of Osteolytic Lesions of the Jaws?

Osteolytic lesions of the jaw are not uncommon. Such lesions usually arise from local pathologies, but some have systemic backgrounds. We describe a 12-year-old girl who presented with an asymptomatic left mandibular swelling. The bony swelling was corresponding to a radiolucent lesion in the left premolar/molar region. This lesion could have represented an inflammatory and developmental odontogenic jaw cyst, giant cell lesion, and odontogenic tumor. However, the workup investigations revealed secondary hyperparathyroidism due to vitamin D deficiency. A vitamin D replacement was initiated with a single I.M. injection of 300,000 I.U followed by 10,000 I.U orally, weekly. Six weeks later, her Vitamin D and parathyroid hormone were normalized, and she showed significant clinical and radiological improvement of the jaw lesion. At 18 months, follow-up the panoramic image revealed complete resolution of the radiolucency and stable normal parathyroid hormone and vitamin D levels. In conclusion, Jaw bone lesions can develop secondary to hyperparathyroidism due to vitamin D deficiency, and this should be ruled out before any surgical intervention. Treatment of such lesions lies in the correction of parathyroid excess with a careful and systematic approach. This may prevent unnecessary surgical intervention in such patients.

Reference values for free 25-hydroxy-vitamin D based on established total 25-hydroxy-vitamin D reference values

Measurements of total 25-hydroxyvitamin D (t25(OH)D) are currently primarily used to assess the vitamin D status. The lipophilic cell membrane can only be passed by the un-bound form of 25-hydroxyvitamin D: free 25-hydroxyvitamin D (f25(OH)D). It is thought that f25(OH)D does reflect its biological actions better than t25(OH)D. However, as of today, there are no established guidelines for the clinical use of f25(OH)D. We analysed 5060 patients with simultaneous measurements of free and total 25(OH). Linear regression was used to study the relationship between free 25(OH)D and total 25(OH)D. We reviewed and used the established t25(OH)D reference values and determined the slope of the relationship between them to calculate reference values for f25(OH)D. F25(OH)D and t25(OH)D showed a strong positive linear (r = 0.8395, p < 0.0001) correlation. The slope of the relationship was 0.2833 ± 0.00257. The recommended threshold level of f25(OH)D is 8.499 pg/mL, corresponding to a target concentration for t25(OH)D of at least 30 ng/mL considered as sufficient in most of the international vitamin D guidelines. The upper limit for vitamin D is less clear in the guidelines. Most experts favour an upper limit for t25(OH)D of 100 ng/mL. This is equivalent to 28.330 pg/mL f25OHD. We established based on international guidelines for t25(OH)D reference values for f25(OH)D that are urgently needed for clinical use of f25(OH)D. However, clinical studies with f25(OH)D to confirm our suggestions are needed but will take time.

Vitamin D requirements in infancy: an updated systematic review

PURPOSE OF REVIEW

Systematic review looking for new evidence for recommendations for vitamin D supplementation in healthy infants based upon the most recent (4 years) available literature.

RECENT FINDINGS

Randomized controlled trials published since 1 January 2017 that related to vitamin D doses in infancy were reviewed. They do not provide any additional evidence that larger, more generous amounts of daily vitamin D beyond the customary recommended 400 international units (IU) daily dose, affect any significant outcome. Larger amounts may lead to serum 25-hydroxyvitamin D [25(OH)D] concentrations that have been reported to be potentially associated with adverse effects, and a daily dose of 1200 IU may even harm in terms of increasing the risks of allergic sensitization.

SUMMARY

There are still many unanswered questions left, in particular, whether or not more 'generous' amounts of vitamin D in infancy may improve long-term health outcomes such as prevention of adult osteoporosis, allergies, or cancer.

What are the new guidelines and position papers in pediatric nutrition: A 2015-2020 overview

BACKGROUND

Nutrition related publications in pediatric population cover wide range of topics and therefore it is usually difficult for clinicians to get an overview of recent nutrition related guidelines or recommendations.

METHODS

The Special Interest Group (SIG) of Pediatrics of European Society for Clinical Nutrition and Metabolism (ESPEN) performed a literature search to capture publications in the last five years aiming to provide the latest information concerning nutritional issues in children in general and in specific diseases and to discuss progression in the field of pediatric nutrition evidence-based practice.

RESULTS

Eight major topics were identified as the most frequently reported including allergy, critical illness, neonatal nutrition, parenteral and enteral nutrition, micronutrients, probiotics and malnutrition. Furthermore, it was noted that many reports were disease focused or included micronutrients and were, therefore, represented as tables.

CONCLUSION

Overall, it has been shown that most reports on nutrition topics in pediatrics were systematic reviews or guidelines/position papers of relevant societies, but many of them basing the conclusion on a limited number of high-quality randomized controlled trials or large observational cohort studies.

Supplementation with vitamin D in the COVID-19 pandemic?

The coronavirus disease 2019 (COVID-19) pandemic was declared a public health emergency of international concern by the World Health Organization. COVID-19 has high transmissibility and could result in acute lung injury in a fraction of patients. By counterbalancing the activity of the renin-angiotensin system, angiotensin-converting enzyme 2, which is the fusion receptor of the virus, plays a protective role against the development of complications of this viral infection. Vitamin D can induce the expression of angiotensin-converting enzyme 2 and regulate the immune system through different mechanisms. Epidemiologic studies of the relationship between vitamin D and various respiratory infections were reviewed and, here, the postulated mechanisms and clinical data supporting the protective role of vitamin D against COVID-19-mediated complications are discussed.

Vitamin D can be effective on the prevention of COVID-19 complications: A narrative review on molecular aspects

The widespread COVID-19 pandemic has been, currently, converted to a catastrophic human health challenge. Vitamin D (VD) and its metabolites have been used as a palliative treatment for chronic inflammatory and infectious diseases from ancient times. In the current study, some molecular aspects of the potential effects of VD against COVID-19 side-effects have been discussed. An arguable role in autophagy or apoptosis control has been suggested for VD through calcium signaling at the mitochondrial and ER levels. 1,25(OH)2D3 is also an immunomodulator that affects the development of B-cells, T-cells, and NK cells in both innate and acquired immunity. The production of some anti-microbial molecules such as defensins and cathelicidins is also stimulated by VD. The overexpression of glutathione, glutathione peroxidase, and superoxide dismutase, and down-regulation of NADPH oxidase are induced by VD to reduce the oxidative stress. Moreover, the multi-organ failure due to a cytokine storm induced by SARS-CoV2 in COVID-19 may be prevented by the immunomodulatory effects of VD. It can also downregulate the renin-angiotensin system which has a protective role against cardiovascular complications induced by COVID-19. Given the many experimental and molecular evidences due to the potential protective effects of VD on the prevention of the COVID-19-induced morbidities, a VD supplementation is suggested to prevent the lethal side-effects of the infection. It is particularly recommended in VD-deficient patients or those at greater risk of serious or critical effects of COVID-19, including the elderly, and patients with pre-existing chronic diseases, especially those in nursing homes, care facilities, and hospitals.

Diagnosis and management of osteoporosis in postmenopausal women in Gulf Cooperation Council (GCC) countries: consensus statement of the GCC countries' osteoporosis societies under the auspices of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO)

A consensus platform is provided by the experts of the Gulf Cooperation Council (GCC) countries' respective osteoporosis societies, on which specific guidelines can be developed further for regional use on the assessment and treatment of postmenopausal women at risk from fractures due to osteoporosis.

INTRODUCTION

Guidance is provided in a Gulf Cooperation Council (GCC) country setting on the assessment and treatment of postmenopausal women at risk from fractures due to osteoporosis, which is an adaptation of the European guidance by Kanis et al., jointly published by the International Osteoporosis Foundation and the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis (ESCEO). The respective osteoporosis societies of the Gulf Cooperation Council (GCC) countries assembled for a unifying consensus on the diagnosis and management of osteoporosis in postmenopausal women for the region.

METHODS

The Chair for Biomarkers of Chronic Diseases (CBCD) in King Saud University (KSU), Riyadh, Kingdom of Saudi Arabia (KSA), in cooperation with the Saudi Osteoporosis Society (SOS), hosted regional experts and respective leaders from different GCC osteoporosis societies, together with an adviser from the ESCEO. An assembly of experts representing the different osteoporosis societies from Saudi Arabia, the UAE, Bahrain, Oman, and Kuwait gathered on February 15-16, 2019 in Riyadh, KSA for the formulation of a general osteoporosis consensus for the region.

RESULTS

The following areas were covered: diagnosis of osteoporosis and assessment of fracture risk; general and pharmacological management of osteoporosis; and hip fractures, vitamin D, recommendation on which FRAX tool to follow, and the importance of country-specific FRAX® and fracture liaison services for secondary fracture prevention.

CONCLUSIONS

A platform is provided on which specific guidelines can be developed for regional use in GCC.

Evaluation of Self-Assessed State of Health and Vitamin D Knowledge in Emirati and International Female Students in United Arab Emirates (UAE)

INTRODUCTION

Globally, vitamin D deficiency is one of the most common deficiencies, affecting nearly half the world's population. The objective of this survey was to assess and compare the knowledge about vitamin D and the perceived state of health in Emirati and international tourist female students in Dubai, United Arab Emirates (UAE).

METHODS

This is a cross-sectional study that took place in universities in Dubai, United Arab Emirates. This survey consisted of 17 multiple choice questions and was adapted from a study recently conducted in Poland. The first part of the survey assessed levels of supplementation, diet and UV exposure. Another section evaluated the participants' self-assessed state of health in terms of vitamin D testing, symptoms related to vitamin D deficiency and general welbeing. The collected data were statistically analyzed using SPSS statistics for windows version 26.0 (SPSS Inc., Chicago, IL, United States). Statistical significance was set at P < 0.05.

RESULTS

105 respondents were Emiratis and 65 were international students. The average age was 21, with an average BMI 23.3 kg/m2. Almost one-third of each group reported using Vitamin D supplements once weekly. The vast majority of both groups reported rarely getting tanned. Almost all participants in both groups reported regular consumption of Vitamin D rich foods. In both groups, more than half reported consuming milk and cheese regularly and up to one-third reported consuming fish in a regular manner. Although more than half of the students rated their health as good; more than two-thirds reported experiencing muscle pain; only half reported having their blood Vitamin D levels measured once; half reported experiencing problems with concentration and more than three-quarters reported experiencing bad mood in the past month. The prevalence of these symptoms was almost similar across different categories of vitamin D supplementation, tanning habits, dietary intake, or nationality. No statistically significant differences were noted between the Emirati and International tourist students regarding any of the studied variables.

CONCLUSION

Notably, more Emirati students were aware of the association between vitamin D and osteoporosis than International tourist students (40% vs. 21.9%, respectively; p < 0.05). On the other hand, both groups had lower knowledge about the relationship between vitamin D deficiency and depression, Rheumatoid Arthritis and Hypertension, and the optimal vitamin D level; however, no statistically significant differences were noted regarding this knowledge of Emiratis and international students.

Vitamin D Megadose: Definition, Efficacy in Bone Metabolism, Risk of Falls and Fractures

Introduction

Currently, approximately more than one billion people around the world are considered to have deficient levels of vitamin D. International consensus recommends vitamin D supplementation to high-risk patients (advanced age, osteoporosis, liver failure, malabsorption syndromes, etc.) and those with levels below 30 ng/mL. There are several vitamin D formulations and dosages available, including megadoses. At the moment, there is no consensus on the definition of megadoses. The purpose of this review is to define what is a megadose and analyze its effectiveness in bone metabolism, risk of fractures and falls.

Conclusion

The administration of doses higher than 100,000 IU of vitamin D is considered a megadose. It is evident that the use of megadoses increases serum concentrations of vitamin D; however, there has been no evidence of a decrease in the risk of falls, vertebral fractures or changes in bone mineral density.

Vitamin D reduces autophagy by regulating NF-κB resistance to Aspergillus fumigatus infection

Vitamin D is one of the indispensable nutrients of human body. When vitamin D is deficient, it can cause a series of related diseases, such as respiratory tract infection. The regulatory role of vitamin D in inflammatory immune response and defense has attracted more and more attention. However, few studies have shown that vitamin D regulates inflammation and autophagy in Aspergillus fumigatus infected lungs. In this study, we will explain the mechanism of vitamin D regulating inflammation and autophagy in Aspergillus fumigatus infected lungs.

METHODS

Different concentrations of Aspergillus fumigatus spores were injected into mice with deficien diets (VitD-) or sufficient vitamin D (VitD + ) , and the survival rates were recorded. Then, the weight changes of rats were measured every other time. At the same time, a gauze was used to filter the lapped lung tissue to get the pulmonary spores and measured the amount of the spores. The mice with the same concentration of Aspergillus fumigatus infected were cut off and the lung tissue for pathological examination in the deficien diets (VitD-) group or sufficient vitamin D (VitD + ) group. Moreover, the expression of inflammation related factors TNF-α, IL-1β, IL-6 in lung was measured by immunohistochemical method. The expression of TNF-α, IL-1β, IL-6 in the serum of vitamin D deficiency and sufficient mice were measured by ELISA. In vitro, we obtained macrophages from healthy mice and mixed cultures of Aspergillus fumigatus spores and lung macrophages in medium with or without vitamin D. After the cells were infected with Aspergillus fumigatus spores, the expressions of NF-κB and IL-8 were detected by RT-PCR and Western blot. The RAW264.7 cells transfected with GFP-LC3BII were mixed with Aspergillus fumigatus spores, and the expression of cell fluorescence was observed by the fluorescence microscope with or without chloroquine and rapamycin , and the autophagy flow of the cells was measured by Western blot. In the RAW264.7 cells, Lentivirus transfection and SiRNA technologies were used to enhance or reduce the expression of the NF-κB gene (siNF-κB) for investgating the influence of high or low expression of NF-κB in the autophagic flow of vitamin D + or vitamin D-treated RAW264.7 cells.

RESULTS

The survival rate of vitamin D deficient mice infected Aspergillus fumigatus was significantly lower than that of vitamin D sufficient mice, while the number of spores, spore activity, pathological changes of lungs and inflammation in the lungs of vitamin D deficient mice were more severe than that of vitamin D sufficient mice. In vitro cell experiments, when cell was stimulated with vitamin D, the expressions of NF-κB and IL-8 in cells were lower. The autophagic flux and TNF-α, IL-1β, IL-6 and LC3BII in vitamin D group were significantly lower than those in vitamin D deficiency group.

CONCLUSIONS

Vitamin D deficiency can aggravate the inflammatory damage in the lungs of Aspergillus fumigatus. When the body is sufficient in vitamin D, if the lungs infect Aspergillus fumigatus spores, the body may resist the infection of Aspergillus fumigatus by reducing the expression of NF-κB, inflammatory factors and autophagy.

Vitamin D in Adolescents: A Systematic Review and Narrative Synthesis of Available Recommendations

PURPOSE

Practical guidelines help clinicians make their preventive and therapeutic choices and improve care management. Our purpose was to collect and synthesize available recommendations concerning vitamin D in adolescents (aged 10-19 years).

METHODS

We searched PubMed, EMBASE, and Cochrane databases from inception to February 5, 2019, for guidance published by different professional associations and governments. We also searched the reference lists of identified recommendations and explored the gray literature using Web search engines. We organized documents by theme: dietary requirements, thresholds, prophylactic supplementation, and treatment of deficiency.

RESULTS

A total of 32 documents were identified. Most of them targeted the general population and not specifically the age group of adolescents. There is a general agreement that adolescents should not have serum 25-hydroxyvitamin D concentrations below 25-30 nmol/L to avoid poor bone health. However, there is lack of consensus on the optimal concentration to aim for, levels varying between 25 nmol/L and 150 nmol/L. Adequate nutritional requirements of vitamin D are also subject to debate with values ranging between 200 IU/d and 1,000 IU/d. The upper tolerable intake is estimated at 4,000 IU/d by all study groups. Certain associations recommend routine vitamin D supplementation in adolescents. The recommended daily preventive doses vary between 400 IU and 4,000 IU, depending on season, skin pigmentation, sun exposure, consumption of vitamin D-fortified foods, body mass index, and coexistence of certain medical conditions. In case of deficiency, different therapeutic regimens of oral vitamin D are proposed depending on the presence of illness and/or the baseline serum 25-hydroxyvitamin D concentrations. Duration of the treatment varies between 4 weeks and 3 months. A maintenance dose is generally recommended after treatment.

CONCLUSIONS

At present, there is no consensus among the different societies about vitamin D needs during adolescence. Stronger, evidence-based guidance is needed to inform clinical practice.

Diagnosis and management of vitamin D deficiency in the Gulf Cooperative Council (GCC) countries: an expert consensus summary statement from the GCC vitamin D advisory board

OBJECTIVE

A summary of recommendations is given within the Gulf Cooperation Council (GCC) setting on the assessment and management of vitamin D deficiency in the region.

METHODS

An assembly of 11 regional experts gathered to formulate an all-inclusive approach to vitamin D deficiency within GCC.

RESULTS AND CONCLUSION

Several gaps were identified before regional guidelines could be developed. These include adequacy and standardization of vitamin D testing, frequency of repeated testing and reference ranges, distinguishing prevention from the treatment of vitamin D deficiency, quality assurance of vitamin D products sold within GCC including contents and origins of products, and cut-points for vitamin D levels in local populations. A platform is created that can be further developed for overall regional implementation.

Impact of vitamin D supplementation on falls and fractures-A critical appraisal of the quality of the evidence and an overview of the available guidelines

INTRODUCTION

The beneficial effect of vitamin D supplementation on musculo-skeletal outcomes have been recently questioned and recommendations regarding supplementation vary widely. The aim of this paper is to systematically assess the quality of the evidence evaluating the effect of vitamin D supplementation on falls and fractures.

METHODS

We conducted a systematic search in Medline, PubMed, and Embase and selected systematic reviews (SRs) / meta-analyses (MAs) of randomized controlled trials (RCTs) on vitamin D supplementation and falls or fracture, published between 2012 - 2018. We identified 5 MAs of RCTs on falls, 4 on fractures and 4 on both outcomes. We applied the critical appraisal tool "A MeaSurement Tool to Assess systematic Reviews 2" - AMSTAR 2 - to assess the quality of the identified MAs.

RESULTS

Vitamin D and calcium supplementation (CaD), compared to calcium only or placebo, may reduce the risk of falls, in institutionalized individuals and/or those from the community, but the data is inconsistent. The largest and most consistent evidence for a protective effect of CaD, compared to placebo or control, is in reducing the risk of hip fracture, by 16-33%, and any fracture, by 5-19%. This effect was demonstrated when combining trials in community-dwelling and institutionalized individuals, potentially driven by data from institutionalized individuals as shown in 3 SRs/MAs. Major limitations to the quality of the evidence include variability in the methodology of MAs, but more importantly, differences between trials in terms of subjects' characteristics, vitamin D regimens, outcome definition and ascertainment, risk of bias, trial duration and/or low power. The quality of the included MAs was moderate to critically low.

CONCLUSIONS

While the effect on falls is inconsistent, CaD reduces the risk of fracture (hip and any fracture), as shown in meta-analyses pooling data of studies combining institutionalized and community individuals. The evidence is however limited by major shortcomings and heterogeneity.

Vitamin D status of female UAE college students and associated risk factors

Objective

Vitamin D deficiency is now recognized as a pandemic with implications for bone health and chronic diseases. The study investigated the vitamin D status and risk factors of subnormal serum vitamin D levels in female college students.

Design

Cross-sectional study.

Setting

American University of Sharjah, United Arab Emirate. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured for the participating female undergraduate college students using a radioimmunoassay kit. All participants answered a questionnaire that included 30 questions, which covered among others the demographic information, dietary intake, sun exposure and autoimmune diseases.

Subjects

Undergraduate college female students (n, 480), aged 18-26 years.

Results

Overall, 47.92% had suboptimal serum vitamin D levels. Results indicated that vitamin D deficiency and other health problems are prevalent among female university students. Risk factors included: wearing hijab by 37.5% of the students that might have interfered with the penetration of UVB radiation into the skin, short time sun exposure, use of sunscreens and limited intake of foods rich in vitamin D.

Conclusions

Vitamin D deficiency is a problem in female college students due to lifestyle, and avoidance of sun exposure. Poor vitamin D status has been associated with increased risk for development of several autoimmune diseases, and other health conditions. This problem needs to be addressed, where prevention of future health consequences in this young group is still possible.

Vitamin D fortification of foods in India: present and past scenario

India is a densely populated country known for its traditional, cultural and lingual diversity. In India Deficiency of vitamin D is seen in both the genders and among all the age groups. Micronutrient deficiencies are steadily adding to the increasing burden of health related co-morbidities with low dietary calcium and magnesium intake in Indian population. Despite lots of sunshine, vitamin D insufficiency is widespread in India according to the age and regions (50-90%). In order to increase vitamin D intake with normal diet, the food industry will have to find a more effective strategy to improve general health conditions. The breadth of widely used foods, including milk, cheese, margarine, dairy products, and various breakfast drinks, can improve the condition of vitamin D deficiency in Asian countries such as India. The requirements for calculating the necessary micronutrients and vitamin D fortification of foods and drinks, successful strategies should be developed and emphasized. There is need to improve the effectiveness of various fruit drinks through fortification of vitamin D, which can reduce vitamin D deficiency in the general population as well as in different age groups.