A global representation of vitamin D status in healthy populations

Development and validation of a semi-quantitative food frequency questionnaire as a tool for assessing dietary vitamin D intake among Korean women

BACKGROUND/OBJECTIVES

Appropriate vitamin D status improves bone health and chronic diseases; it has shown benefits during the coronavirus disease 2019 pandemic. Therefore, assessing vitamin D status is crucial. However, limited research on vitamin D intake among Koreans complicates understanding of its consumption. This study aimed to develop and validate a semi-quantitative food frequency questionnaire (FFQ) to assess vitamin D intake among Koreans.

SUBJECTS/METHODS

A vitamin D FFQ was developed to include 31 vitamin D source foods from 8 food groups frequently consumed by Korean adults. The study included 152 women residing in a major city in South Korea. From September 2020 to August 2022, intake was surveyed using a 12-day dietary record (12-day DR) across 4 seasons, and 2 vitamin D FFQs were conducted approximately 9-11 months apart (FFQ1 and FFQ2). Reproducibility (FFQ1 vs. FFQ2) and validity (FFQ2 vs. 12-day DR) were verified using Spearman's rank correlation, weighted kappa coefficient, intraclass correlation, and Bland-Altman plots.

RESULTS

The vitamin D intake of Korean women using the newly developed vitamin D FFQ was higher at FFQ1 (4.90 µg/day) and FFQ2 (4.58 µg/day) compared with the 12-day DR (4.07 µg/day). Additionally, the results for reproducibility and validity were demonstrated through the Spearman's rank correlation coefficient (reproducibility, 0.592; validity, 0.460), weighted kappa coefficient (reproducibility, 0.379; validity, 0.284), intraclass correlation coefficient (reproducibility, 0.599; validity, 0.543), and Bland-Altman plots (reproducibility index, 3.95%; validity index, 3.95%).

CONCLUSION

This study confirmed the newly developed vitamin D FFQ is reliable and valid for assessing vitamin D intake among Korean women. These results suggest the FFQ is an effective tool for dietary assessment, particularly in large-scale studies where year-round monitoring may not be feasible. Further validation in Korean men is crucial to enhance its applicability, enabling significant contributions to assessing vitamin D intake among Korean adults.

Effect of vitamin D on risk of falls and fractures - The contribution of recent mega-trials

Three recently-completed, large clinical trials in the U.S, New Zealand, and Australia, referred to herein as the 'mega-trials', were conducted to determine the impact of supplemental vitamin D on a variety of outcomes including falls and fractures. The trials were similar in design and collectively included over 50,000 generally vitamin D replete, older men and women. The mega-trials established that vitamin D supplementation with the equivalent of 2000 to 3300 IU/d of vitamin D3 had no favorable effect on risk of falls or fractures. This review focuses on specific design elements of the trials and how they likely influenced these trial findings. While these trials were in progress, evidence emerged that circulating 25-hydroxyvitamin D levels have a U-shaped association with risk of falling, raising concern about a potential untoward effect of high dose supplementation. There is compelling evidence that in older, vitamin D- and calcium-insufficient nursing home residents, the combination of vitamin D and calcium in modest replacement doses dramatically reduces the risk of hip and other fractures. Community-dwelling older adults in many populous countries around the globe have widespread vitamin D and calcium insufficiency. It is time to follow the evidence trail and determine the effect of vitamin D and calcium replacement on their risk of falls and fractures.

Optimisation of vitamin D status in global populations

Vitamin D is important for musculoskeletal health. Concentrations of 25-hydroxyvitamin D, the most commonly measured metabolite, vary markedly around the world and are influenced by many factors including sun exposure, skin pigmentation, covering, season and supplement use. Whilst overt vitamin D deficiency with biochemical consequences presents an increased risk of severe sequelae such as rickets, osteomalacia or cardiomyopathy and usually warrants prompt replacement treatment, the role of vitamin D supplementation in the population presents a different set of considerations. Here the issue is to keep, on average, the population at a level whereby the risk of adverse health outcomes in the population is minimised. This position paper, which complements recently published work from the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, addresses key considerations regarding vitamin D assessment and intervention from the population perspective. This position paper, on behalf of the International Osteoporosis Foundation Vitamin D Working Group, summarises the burden and possible amelioration of vitamin D deficiency in global populations. It addresses key issues including screening, supplementation and food fortification.

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.

Prevalence and patterns of vitamin D deficiency and its role in cognitive functioning in a cohort from South India

Vitamin D (VitD) is a naturally occurring, fat-soluble vitamin which regulates calcium and phosphate homeostasis in the human body and is also known to have a neuroprotective role. VitD deficiency has often been associated with impaired cognition and a higher risk of dementia. In this study, we aimed to explore the relationship between levels of VitD and cognitive functioning in adult individuals. 982 cognitively healthy adults (≥ 45 years) were recruited as part of the CBR-Tata Longitudinal Study for Aging (TLSA). Addenbrooke's cognitive examination-III (ACE-III) and Hindi mental status examination (HMSE) were used to measure cognitive functioning. 25-hydroxyvitamin D [25(OH)D] levels were measured from the collected serum sample and classified into three groups- deficient (< 20 ng/ml), insufficient (20-29 ng/ml) and normal (≥ 30 ng/ml). Statistical analysis was done using IBM SPSS software, version 28.0.1.1(15). The mean age of the participants was 61.24 ± 9 years. Among 982 participants, 572 (58%) were deficient, 224 (23%) insufficient and only 186 (19%) had normal levels of VitD. Kruskal-Wallis H test revealed a significant difference in age (p = 0.015) and education (p = 0.021) across VitD levels and the Chi-square test revealed a significant association between gender (p = 0.001) and dyslipidemia status (p = 0.045) with VitD levels. After adjusting for age, education, gender and dyslipidemia status, GLM revealed that individuals with deficient (p = 0.038) levels of VitD had lower scores in ACE-III verbal fluency as compared to normal. Additionally, we also found that 91.2% individuals who had VitD deficiency were also having dyslipidemia. It is concerning that VitD deficiency impacts lipid metabolism. Lower levels of VitD also negatively impacts verbal fluency in adult individuals. Verbal fluency involves higher order cognitive functions and this result provides us with a scope to further investigate the different domains of cognition in relation to VitD deficiency and other associated disorders.

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.

Impact of 25-hydroxy vitamin D levels in severe acute respiratory syndrome coronavirus 2 patients with respect to clinical and biochemical profile: An experience from a tertiary care hospital

INTRODUCTION

Among the many micronutrients, Vitamin D deficiency has been associated with the severity of Severe Acute Respiratory Syndrome Coronavirus 2 patients.

DESIGN AND METHODS

A retrospective observational study was conducted on Severe acute respiratory syndrome coronavirus 2 patients admitted to a tertiary care hospital between April 5, 2021, and May 5, 2021.

RESULTS

Among 285 patients,77.2 % of the patients who stayed for more than 14 days were either Vitamin D insufficient or deficient [P value < 0.05]. In our study, the mean oxygen saturation at admission was 85.7 % in the Vitamin D deficiency group compared to 95.6 % in Vitamin D sufficiency patients [P value < 0.05]. Mean serum ferritin was 398 ng/ml in the Vitamin D deficiency group compared to 393 ng/ml in Vitamin D sufficiency patients [P value > 0.05]. The mean C-reactive protein was 107.6 mg/ml in the Vitamin D deficiency group compared to 21.8 ng/ml in Vitamin D sufficiency patients [P value < 0.05]. The mean D-Dimer was 2268 ng/ml in the Vitamin D deficiency group compared to 781 ng/ml in Vitamin D sufficiency patients [P value < 0.05]. In the non-survivor group,97.4 % were Vitamin D deficient and insufficient. Only 2 % of the patients who survived were Vitamin D deficient [P value < 0.05].

CONCLUSION

We observed that low 25-hydroxy Vitamin D levels were associated with lower oxygen saturation and higher acute physiology and chronic health evaluation II scores, requiring a more extended stay in the hospital. C-reactive protein and D-dimers were significantly higher in Vitamin D deficient patients, suggesting severe disease. We did not find statistically significant findings in the case of the correlation of serum ferritin levels with Vitamin D status.

Association Between Vitamin D Deficiency and Testosterone Levels in Adult Males: A Systematic Review

Vitamin D deficiency and its potential impact on testosterone levels have been subjects of scientific interest. This systematic review aims to evaluate the association between vitamin D deficiency and testosterone levels in adult males and examine the effects of vitamin D supplementation on testosterone. A comprehensive literature search was conducted in accordance with the PRISMA guidelines across PubMed, Google Scholar, and ScienceDirect. The inclusion criteria involved studies published in English between 2013 and 2023, which investigated the correlation between vitamin D and testosterone levels in adult males. The process of data extraction and synthesis encompassed various aspects, including study characteristics, participant demographics, measurement methods, and outcomes pertaining to the association. The initial search resulted in a pool of 354,235 articles. Through the application of relevant filters and the review of titles and abstracts, 48 articles were chosen for further assessment. Out of these, eight studies fulfilled the inclusion criteria and were ultimately incorporated into the final review. The included studies consisted of four cross-sectional studies, three randomized controlled trials (RCTs), and one analysis utilizing Mendelian randomization. The results showed heterogeneity among the studies, as some reported a positive correlation between vitamin D levels and testosterone, while others did not find a significant association. The effects of vitamin D supplementation on testosterone levels were inconclusive, with limited evidence of significant changes in total testosterone. However, potential influences on sex hormone-binding globulin and free testosterone levels were observed. To establish more definitive evidence regarding the impact of vitamin D on testosterone levels, there is a need for further well-designed, long-term RCTs that encompass diverse populations.

Joint Detection of Serum Vitamin D, Body Mass Index, and Tumor Necrosis Factor Alpha for the Diagnosis of Crohn's Disease

OBJECTIVE

Vitamin D (VD) deficiency was reported to contribute to the progression of Crohn's disease (CD) and affect the prognosis of CD patients. This study investigated the role of serum VD, body mass index (BMI), and tumor necrosis factor alpha (TNF-α) in the diagnosis of Crohn's disease.

METHODS

CD patients (n=76) and healthy subjects (n=76) were enrolled between May 2019 and December 2020. The serum 25-hydroxyvitamin D [25(OH)D] levels, BMI, and TNF-α levels, together with other biochemical parameters, were assessed before treatment. The diagnostic efficacy of the single and joint detection of serum 25(OH)D, BMI, and TNF-α was determined using receiver operating characteristic (ROC) curves.

RESULTS

The levels of 25(OH) D, BMI, and nutritional indicators, including hemoglobin, total protein, albumin, and high-density lipoprotein cholesterol, were much lower, and the TNF-α levels were much higher in the CD patients than in the healthy subjects (P<0.05 for all). The areas under the ROC curve for the single detection of 25(OH)D, BMI, and TNF-α were 0.887, 0.896, and 0.838, respectively, with the optimal cutoff values being 20.64 ng/mL, 19.77 kg/m², and 6.85 fmol/mL, respectively. The diagnostic efficacy of the joint detection of 25(OH)D, BMI, and TNF-α was the highest, with an area under the ROC curve of 0.988 (95%CI: 0.968-1.000).

CONCLUSION

The joint detection of 25(OH)D, TNF-α, and BMI showed high sensitivity, specificity, and accuracy in CD diagnosis; thus, it would be effective for the diagnosis of CD in clinical practice.

Vitamin D and Bone fragility in Individuals with Osteogenesis Imperfecta: A Scoping Review

Vitamin D affects several body functions, and thus general health, due to its pleiotropic activity. It plays a key role in bone metabolism, and its deficiency impacts bone development, leading to bone fragility. In osteogenesis imperfecta (OI), a group of hereditary connective tissue disorders characterized by bone fragility, additional factors, such as vitamin D deficiency, can affect the expression of the phenotype and aggravate the disorder. The aim of this scoping review was to assess the incidence of vitamin D deficit in OI patients and the association between vitamin D status and supplementation in individuals affected by OI. We searched the PubMed Central and Embase databases and included studies published between January/2000 and October/2022 evaluating vitamin D measurement and status (normal, insufficiency, deficiency) and supplementation for OI. A total of 263 articles were identified, of which 45 were screened by title and abstract, and 10 were included after a full-text review. The review showed that low levels of vitamin D was a frequent finding in OI patients. Vitamin D supplementation was mainly indicated along with drug therapy and calcium intake. Even if widely used in clinical practice, vitamin D supplementation for OI individuals still needs a better characterization and harmonized frame for its use in the clinical setting, as well as further studies focusing on its effect on bone fragility.

Low baseline vitamin D levels increase the risk of bone metastases among females with breast cancer - Hospital based cohort study

BACKGROUND

Serum vitamin D (Vit-D) has been linked to the development of breast cancer (BC); however, their effect on pathological features and outcomes is undetermined. The purpose of this study was to examine the prognostic significance of baseline Vit-D levels and their effect on clinical outcomes.

METHODS

We evaluated baseline serum Vit-D levels and baseline clinic-pathological features of female patients with non-metastatic BC between October 2018 and December 2019. A low Vit-D level was described as less than 30 nanogram per liter (ng/l). Patients were observed for a median of 24 months. To evaluate relationships between qualitative variables, the chi-square test was used. The Kaplan-Meier technique was used for survival analysis, and the log-rank test was used to compare the two survival curves. Correlation analysis was also used to examine the link between Vit-D levels and clinical outcomes.

RESULTS

The eligibility criteria were fulfilled by 221 patients. The median age of onset was (50.7). The median Vit-D level was (23.1 ng/l) with a range of (4-46 ng/l). Approximately half of the patients (56.5%) had Vit-D levels < 30 ng/l, with HER2 positive and triple negative (TNBC) patients having a greater proportion of low Vit-D levels (p = <0.001). Patients with low baseline Vit-D levels had a larger tumor size, more positive lymph nodes, and were diagnosed at a later stage. Following follow-up, Vit-D deficiency was associated with a significantly increased risk of bone metastases (HR 3.37, 95% CI 1.32-8.59, p = 0.006), and Vit-D levels were significantly correlated with disease-free survival (DFS) and overall survival (OS) (r = 0.850, r = 0.573, p < 0.00, p < 0.001, respectively).

CONCLUSIONS

Low serum Vit-D is associated with advanced stage and adverse characteristics. It is more prevalent in HER-2 positive and TNBC patients; it increases the chance of bone metastases, and has a significant correlation with DFS and OS.

Calcifediol: Why, When, How Much?

Vitamin D deficiency is a constantly growing health problem worldwide. Adults affected with hypovitaminosis D could experience negative consequences on their musculoskeletal system and extra-skeletal health. In fact, an optimal vitamin D status is essential to ensure the correct bone, calcium, and phosphate homeostasis. To improve vitamin D status, it is important to not only increase the intake of food fortified with vitamin D, but also to administer vitamin D supplementation when required. Vitamin D3 (cholecalciferol) is the most widely used supplement. In recent years, the administration of calcifediol (25(OH)D3), the direct precursor of the biologically active form of vitamin D3, as oral vitamin D supplementation has progressively grown. Here, we report the potential medical benefits of some peculiar biological actions of calcifediol, discussing the possible specific clinical scenarios in which the oral intake of calcifediol could be most effective to restore the correct serum levels of 25(OH)D3. In summary, the aim of this review is to provide insights into calcifediol-related rapid non-genomic responses and the possible use of this vitamin D metabolite as a supplement for the treatment of people with a higher risk of hypovitaminosis D.

Vitamin D Determinants, Status, and Antioxidant/Anti-inflammatory-Related Effects in Cardiovascular Risk and Disease: Not the Last Word in the Controversy

Beyond its key role in calcium homeostasis, vitamin D has been found to significantly affect the cardiovascular (CV) system. In fact, low vitamin D levels have been associated with increased CV risk, as well as increased CV morbidity and mortality. The majority of effects of this molecule are related directly or indirectly to its antioxidative and anti-inflammatory properties. Generally, vitamin D insufficiency is considered for 25-hydroxyvitamin D (25(OH)D) levels between 21-29 ng/mL (corresponding to 52.5-72.5 nmol/L), deficiency as 25(OH)D levels less than 20 ng/mL (<50 nmol/L), and extreme deficiency as 25(OH)D less than 10 ng/mL (<25 nmol/L). However, the definition of an optimal vitamin D status, as defined by 25(OH)D, remains controversial for many extra-bone conditions, including CV disease. In this review, confounding factors affecting the 25(OH)D measurement and status will be discussed. In particular, available evidence on the mechanism and role of vitamin D in relation to CV risk and disease through its antioxidant effect will be reported, also facing the aspect regarding the debate on the minimum blood 25(OH)D level required to ensure optimal CV health.

Severe deficiency of vitamin D has no negative effect on physical performance during military training

BACKGROUND

Decreased physical fitness and inferior physical performance are potentially life-threatening risk factors in a combat situation. To examine the effect of vitamin D on physical performance, a prospective study of young men conscripts in the Estonian Army was designed. The hypothesis of the study was that severe deficiency of vitamin D has a negative effect on physical performance.

METHODS

All conscripts (N.=410) entering 10-month military service in July 2015 at the Kuperjanov Battalion were asked to participate. Initially, a total of 98 conscripts volunteered to participate. A prospective longitudinal study with a 10-month follow-up period was performed. The Army Physical Fitness Test (APFT) was performed three times, and hand grip strength, and blood serum values of 25(OH)D, parathyroid hormone (PTH) and calcium (Ca) were measured four times.

RESULTS

A significant decrease in the levels of 25(OH)D compared with baseline values were found, with a lowest mean value of 31.9 nmol/L in March 2016 (P<0.001). No significant differences were found in serum Ca levels. In March 2016, PTH was significantly higher in the severe deficiency group (<25 nmol/L of 25(OH)D) (P=0.02). No significant differences were found in terms of the APFT or hand grip strength between conscripts with severe deficiency of 25(OH)D or values >25 nmol/L. The main finding of the present study was that severe 25(OH)D deficiency was common among male conscripts during the winter season but had no negative effect on physical performance in terms of the APFT test and hand grip strength test.

CONCLUSIONS

Severe vitamin D deficiency during the winter season is common but has no negative effect on physical performance in young, physically active men in military service.

A prospective analysis of concentration of 25-OHD between northern and southern district in Japan in year-round study

Although osteoporotic patients have already been recognized as having a low-volume vitamin D status, the concentration of active vitamin D precursor has not been studied in detail. This trial aimed to clarify the concentration of 25-hydroxyvitamin D (25-OHD), which is a natural type of vitamin D and compare between 2 separate areas in Japan. To compare and clarify the concentration of 25-OHD between 2 separate areas, Japanese patients who were diagnosed as having osteoporosis based on bone mineral density were studied. We analyzed 2 different hospitals' patients whose residence is separated into a northern district (Akita city: north latitude 39" 43') and a southern district (Shizuoka city: north latitude 34" 58'). Both of them have completely different daylight hours. Three-hundred sixty eight patients (174 in Akita, 194 in Shizuoka) were enrolled in this trial to compare the differences of concentration of 25-OHD by Welch's t t-test. There were significant differences in the concentration of 25-OHD and age between them. Akita patients were significantly higher than that of Shizuoka patients despite Shizuoka having much daylight hours of Akita. In conclusion, there might be no relationship between the concentration of 25 OHD and exposure to sunlight.

Disclosure of funding sources and conflicts of interest in evidence underpinning vitamin D and calcium recommendations in bone health guidelines

OBJECTIVE

The present study aims to examine the relationship between study funding sources, author conflicts of interest (COI) and conclusions in studies supporting vitamin D and Ca intake cited in bone health guideline recommendations.

DESIGN

Cross-sectional.

SETTING

Forty-seven global bone health guidelines with vitamin D and/or Ca recommendations for adults aged 40 years and above.

PARTICIPANTS

The evidence cited to support the recommendations was extracted by two independent reviewers and classified by type of recommendation, article characteristics, study design, types of funding sources and conflict of interest (COI) disclosure and direction of study conclusions.

RESULTS

Of 156 articles cited to support the bone health recommendations, 120 (77 %) disclosed a funding source, and 43 (28 %) declared that at least one author had a COI. Compared with articles with non-commercial or no funding source, those funded by commercial sponsors tended to have a study conclusion favourable towards vitamin D/Ca (relative risk (95 % CI): 1·32 (0·94, 1·87), P = 0·16), but the association was not statistically significant (Fisher's exact test). Compared to those with a COI disclosure statement, articles with missing or unclear COI disclosure were more likely to have favourable conclusions (1·56 (1·05, 2·31), P = 0·017) (Fisher's exact test).

CONCLUSION

In the evidence underpinning a sample of global bone health guidelines, COI disclosure was low and studies with missing or unclear COI disclosures were more likely to have favourable study conclusions than those with disclosures, suggesting a need for greater transparency of COI in bone health guidelines.

Association between Blood Vitamin D Levels and Regular Physical Activity in Korean Adolescents

This study aimed to investigate the relationship between vitamin D levels and physical activity in adolescents using data from the Korea National Health and Nutrition Survey (KNHANES). The serum vitamin D concentrations were measured between 2008 and 2014 and analyzed. Adolescents aged 13 to 18 years comprised 4527 of the 61,370 participants surveyed. A final dataset including 2811 adolescents was obtained after those with missing data were excluded. Those who did not participate or only participated in 1−3 days of intense physical activity (p < 0.001), moderate physical activity (p = 0.002), and muscular exercise (weight training) (p < 0.001) showed a higher level of vitamin D deficiency than those who performed the same activities 4−7 days per week. Our results showed that most of the adolescents (76%) were vitamin D-deficient, and the risk was higher among high school than middle school students (odds ratio (OR) = 1.70, 95% confidence interval (CI) = 1.40−2.06; p < 0.001) and higher in girls than boys (OR = 1.43, 95% CI = 1.18−1.72; p < 0.001). Reduced participation in physical activity was correlated with vitamin D deficiency. Furthermore, vitamin D deficiency was associated with a lower frequency of participation in all forms of physical activity, and the association increased significantly with an increase in body mass index.

Prevalence and Correlates of Vitamin D Deficiency in Children Aged Less than Two Years: A Cross-Sectional Study from Aseer Region, Southwestern Saudi Arabia

Background: Vitamin D is an essential nutrient for bone growth, mineralization, and other metabolic processes in the human body. Hence, insufficiency or deficiency of this vitamin can have long-term effects, particularly for children. Objectives: The aims of this study were to determine the prevalence of vitamin D deficiency in children up to 2 years of age and investigate the independent predictors of vitamin D deficiency. Methodology: This cross-sectional study was conducted among 484 children aged up to two years who were admitted to the hospital for the treatment of any acute condition from January to November 2021. Serum 25(OH)D was used to determine the level of vitamin D. The serum 25(OH)D was categorized into 3 groups: Sufficiency (>30 ng/mL), insufficiency (20−30 ng/mL), and the deficiency (<20 ng/mL). Results: Overall, vitamin D deficiency was observed in 70.5% of the children, of whom 45.9% had insufficient levels, and one-fourth (24.6%) showed deficiency. The children aged 2−12 months (infants) were more likely to be vitamin deficient compared to children aged 12 months and above. The children who lived in urban areas had a threefold increased risk of vitamin D deficiency (aOR = 3.0, 95% CI 1.78−5.08). The children who were exposed to sunlight for less than 3 days per week experienced a higher risk of developing vitamin D deficiency (aOR = 4.17, 95% CI 2.04−10.88). Children who had received only breast milk were more than two times more likely to experience vitamin D deficiency (aOR = 2.42, 95% CI 1.12−5.23) compared to their counterparts. Conclusion: Our study reveals a high prevalence of vitamin D deficiency among children aged up to two years. Infants, urban dwellers, only breastfed, and exposure to sunlight for less than three days per week were identified to be the independent risk factors for vitamin D deficiency. The results of this work call for enhancing awareness to ensure adequate levels of vitamin D for better health of the children in this region of Saudi Arabia.

COVID-19 transmission risk factors

We analyze risk factors correlated with the initial transmission growth rate of the recent COVID-19 pandemic in different countries. The number of cases follows in its early stages an almost exponential expansion; we chose as a starting point in each country the first day d i with 30 cases and we fitted for 12 days, capturing thus the early exponential growth. We looked then for linear correlations of the exponents α with other variables, for a sample of 126 countries. We find a positive correlation, i.e. faster spread of COVID-19, with high confidence level with the following variables, with respective p -value: low Temperature (4 ⋅ 10 - 7 ), high ratio of old vs. working-age people (3 ⋅ 10 - 6 ), life expectancy (8 ⋅ 10 - 6 ), number of international tourists (1 ⋅ 10 - 5 ), earlier epidemic starting date d i (2 ⋅ 10 - 5 ), high level of physical contact in greeting habits (6 ⋅ 10 - 5 ), lung cancer prevalence (6 ⋅ 10 - 5 ), obesity in males (1 ⋅ 10 - 4 ), share of population in urban areas (2 ⋅ 10 - 4 ), cancer prevalence (3 ⋅ 10 - 4 ), alcohol consumption (0.0019 ), daily smoking prevalence (0.0036 ), and UV index (0.004 , 73 countries). We also find a correlation with low Vitamin D serum levels (0.002 - 0.006 ), but on a smaller sample, ∼ 50 countries, to be confirmed on a larger sample. There is highly significant correlation also with blood types: positive correlation with types RH- (3 ⋅ 10 - 5 ) and A+ (3 ⋅ 10 - 3 ), negative correlation with B+ (2 ⋅ 10 - 4 ). We also find positive correlation with moderate confidence level (p -value of 0.02 ∼ 0.03 ) with: CO2/SO emissions, type-1 diabetes in children, low vaccination coverage for Tuberculosis (BCG). Several of the above variables are correlated with each other, and so they are likely to have common interpretations. We thus performed a Principal Component Analysis, to find the significant independent linear combinations of such variables. The variables with loadings of at least 0.3 on the significant PCA are: greeting habits, urbanization, epidemic starting date, number of international tourists, temperature, lung cancer, smoking, and obesity in males. We also analyzed the possible existence of a bias: countries with low GDP-per capita might have less intense testing, and we discuss correlation with the above variables.

25-Hydroxyvitamin D reference percentiles and the role of their determinants among European children and adolescents

BACKGROUND/OBJECTIVES

To provide age- and sex-specific percentile curves of serum 25-hydroxyvitamin D (25(OH)D) by determinants from 3-<15 year-old European children, and to analyse how modifiable determinants influence 25(OH)D.

SUBJECTS/METHODS

Serum samples were collected from children of eight European countries participating in the multicenter IDEFICS/I.Family cohort studies. Serum 25(OH)D concentrations were analysed in a central lab by a chemiluminescence assay and the values from 2171 children (N = 3606 measurements) were used to estimate percentile curves using the generalized additive model for location, scale and shape. The association of 25(OH)D with time spent outdoors was investigated considering sex, age, country, parental education, BMI z score, UV radiation, and dietary vitamin D in regressions models.

RESULTS

The age- and sex-specific 5th and 95th percentiles of 25(OH)D ranged from 16.5 to 73.3 and 20.8 to 79.3 nmol/l in girls and boys, respectively. A total of 63% had deficient (<50 nmol/l), 33% insufficient (50-<75 nmol/l) and 3% sufficient (≥75 nmol/l) levels. 25(OH)D increased with increasing UV radiation, time spent outdoors, and vitamin D intake and slightly decreased with increasing BMI z score and age. The odds ratio (OR) for a non-deficient 25(OH)D status (reference category: deficient status) by one additional hour spent outdoors was 1.21, 95% CI [1.12-1.31], i.e., children who spent one more hour per day outdoors than other children had a 21% higher chance of a non-deficient than a deficient status.

CONCLUSION

A majority of children suffer from deficient 25(OH)D. UV radiation, outdoor time, and dietary vitamin D are important determinants of 25(OH)D.

The Relationship Between Low Serum Vitamin D Level and Early Dental Implant Failure: A Systematic Review

The variety in shape and type of dental implants in the present time is considered one of the most successful evolutions in dentistry. This facilitates dental treatment options to restore patient function and appearance. However, numerous significant factors influence the predictability of survival or the success rates of dental implants, some of which, such as vitamin D levels, have not been included in many studies. The main purpose of this systematic review was to investigate whether there is a relationship between low serum levels of vitamin D and early dental implant failures (EDIFs). Our literature search involved international databases including PubMed, Directory of Open Access Journals (DOAJ), and Web of Science. Initially, according to our search criteria, 1200 studies were found. After excluding duplicates, incomplete studies, and studies not meeting our inclusion criteria, only six human studies were included in this research and analyzed. Finally, upon meticulous analysis of included studies, this systematic review revealed inconsistent results in articles with respect to the association between vitamin D deficiency and implant failures. Large-scale studies, especially clinically relevant studies, on this subject is recommended.

Maternal vitamin D deficiency and GDM risk: evidence for the case of investing more attention in antenatal clinics

Gestational diabetes mellitus (GDM) is a global public health problem, and in India, it affects about 20% of pregnancies. India, despite being a tropical country with abundant sunshine has a high prevalence (80%) of vitamin D deficiency (VDD) among reproductive-aged women. Global and Indian evidence links VDD with a higher risk of hyperglycaemia in pregnancy and GDM. VDD has also been implicated in gestational hypertension, preterm birth and poorer offspring health. Global scientific consensus acknowledges the need for maternal vitamin D screening and supplementation, but knowledge gaps exist about optimal blood levels (50-100 nmol/l), and the required vitamin D dosage (400-4000 IU). Diet can provide <10% of the vitamin D requirements, food fortification can deliver limited amounts, and hence optimal antenatal supplementation is key. Prenatal calcium supplements containing 400 IU of vitamin D may be sufficient for calcium absorption and bone health, but may not provide immunomodulatory benefits, including GDM prevention. Increasing evidence calls for higher maternal vitamin D requirements (2000-4000 IU) for skeletal, metabolic and immune health benefits. Current screening and supplementation for maternal VDD in India is low. We need to invest in future studies to determine optimal maternal vitamin D requirements and formulate policies for vitamin D supplementation to prevent GDM. Improving the maternal vitamin D status is an important nutritional priority for policymakers to reduce the large economic burden of non-communicable diseases (10% of India's gross domestic product), and eventually achieve the 2030 UN sustainable development goals.

Dietary Magnesium Intake Affects the Association Between Serum Vitamin D and Type 2 Diabetes: A Cross-Sectional Study

Introduction: Circulating vitamin D concentrations have been associated with the risk of type 2 diabetes (T2D). Magnesium has also been reported to be associated with lower T2D risk. Besides, magnesium is an essential cofactor for vitamin D activation. However, the effect of dietary magnesium intake on the association between vitamin D and the risk of T2D has not been studied comprehensively. Therefore, we designed this cross-sectional study to assess the effect modification of magnesium intake on the association between vitamin D and risk of T2D.

Research Design and Methods: The present study analyzed data from the National Health and Nutrition Examination Survey (NHANES) continuously from 2007 to 2014, involving 10,249 participants. By having stratified participants based on magnesium intake category (low magnesium intake <267 mg/day; high magnesium intake: ≥267 mg/day), we further evaluated the difference (interaction test) between the relationship of vitamin D with the risk of T2D among low magnesium intake participants and high magnesium intake participants using weighted multivariable logistic regression.

Results: In this cross-sectional study, the association of serum vitamin D with the incidence of T2D appeared to differ between the low magnesium intake group and the high magnesium intake group (OR: 0.968, 95%Cl: 0.919–1.02 vs. OR: 0.925, 95%Cl: 0.883–0.97). Furthermore, there was evidence of interaction between vitamin D levels and magnesium intake on decreasing the incidence of T2D (p-value for interaction = 0.001).

Conclusions: The results of our study indicated that magnesium intake might affect the association of serum vitamin D with the risk of T2D. Such a finding requires further randomized controlled trials to provide more evidence.

Effect of Application of Different Exercise Intensities on Vitamin D and Parathormone in Children with Down's Syndrome

BACKGROUND

Children with Down's syndrome are more liable to vitamin D deficiency. Treating this deficiency with supplements is associated with the risk of intoxication.

AIM

The study is aimed at comparing the effect of two exercise intensities on the modulation of vitamin D and parathormone levels in children with DS.

METHODS

Forty-four DS male children aged from 8 to 12 years participated in the study. They were assigned randomly into two equal groups. Group I received high-intensity treadmill aerobic exercises, and group II received moderate-intensity T-AE, three times per week for three months. The blood samples were collected from both groups before the intervention, after one month of intervention, then after three months of intervention to assess serum 25(OH)D and PTH levels.

RESULTS

Repeated measure MANOVA revealed that the high-intensity T-AE induced a significant increase in 25(OH)D after one month and after three months while it significantly decreased PTH only after three months. Moderate-intensity T-AE had a nonsignificant effect on both hormones.

CONCLUSION

The current study concluded that the high-intensity T-AE improved both vitamin D and parathormone serum levels after three months of intervention.

Trends in Vitamin D Status Around the World

Vitamin D status varies across all continents and countries. Vitamin D status usually is adequate in Latin America and Australia, but in contrast it is very low in the Middle East and some countries in Asia. Trends in vitamin D status, whether it improves or declines over the years, carry important messages. Trends usually are small, but can be predictors and indicators of general health. Vitamin D status has improved in the older population in the United States, and improvement relates to dairy use and vitamin D supplements. To the contrary, vitamin D status has declined in the Inuit population of Canada due to a change from a traditional fish diet to a Western diet. A large improvement was seen in Finland after mandatory fortification of dairy products was introduced. Determinants of decline are less sun exposure, increased use of sunscreen, increase of body mass index (BMI), less physical activity, and poor socioeconomic status. Determinants of increase are food fortification with vitamin D and vitamin D supplements. Food fortification can lead to a population-wide increase in vitamin D status as shown by the Finnish example. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The effect of vitamin D and exercise on balance and fall risk in postmenopausal women: A randomised controlled study

OBJECTIVE

To evaluate the effects of vitamin D and exercise on balance, fall risk and quality of life (QoL) in postmenopausal women.

METHODS

In this prospective, randomised, controlled, single-blind study postmenopausal women aged 50-70 years were included. Participants with <25nmol/L 25(OH) vitamin D were randomised to three groups: group-I (vitamin D replacement) (n = 21), group-II (core and balance exercises) (n = 18), and group-III (vitamin D replacement plus core and balance exercises) (n = 20). The participants with >75nmol/L 25(OH) vitamin D (group-IV) (n = 40) were designated as control group and received the core and balance exercises. The participants were evaluated before and after 8 weeks with Berg balance test and Biodex balance system (postural stability and fall risk tests) for balance and Nottingham Health Profile (NHP) for QoL.

RESULTS

Group IV had better baseline BBT, NHP pain, NHP emotional reactions, NHP social isolation subdomain and total score. After treatment, all groups showed significant improvement in balance (except group I, mediolateral stability index) and QoL (except group II). There was no significant difference between groups (I, II and III) after intervention.

CONCLUSION

Vitamin D replacement therapy has positive effects on balance and QoL. Core strengthening and balance exercises are essential for better balance and fall prevention in postmenopausal women. Any superior effect of vitamin D or exercise on each other was not determined.

Knowledge and Practice of Infants Exposure to Sunlight Among Lactating Mothers Attending at Yirgalem Hospital, Sidama Regional State

Background:

Exposure to sunlight is vital for the synthesis of vitamin-D and vitamin D plays an important role in growth and bones strength. Therefore, this study aimed to assess the knowledge and practice of infants exposure to sunlight among lactating women.

Methods:

A cross-sectional study was conducted from May 01 to 30, 2019 among 327 infant coupled lactating mothers attended at Yirgalem General Hospital. An interviewer-administered questionnaire was used to collect relevant data through a convenient sampling technique.

Results:

A total of 84.7% of respondents exposed infants to sunlight. More than 94% knew the benefit of exposing infants to sunlight. About 20.9%, 25.6%, and 19.9% of mothers exposed infants to sunlight within 15, 16 to 30, and 31 to 45 days of birth, respectively. In addition, 59.9% of respondents exposed infants to sunshine daily and 72.2% exposed without clothing the infants’ body. Moreover, 63.5% of mothers have applied lubricants and overall 54.5% of mothers exposed infants to sunlight in good practice. Unemployed women were 4.7 times more likely (aOR; 95%CI: 4.7; 2.0-11.4) to expose infants to sunlight when compared to those employed, while women whose husbands have at least secondary education level were 5.1 times more likely (aOR; 95%CI: 5.1; 1.6-16.1) to expose infants to sunlight when compared to those unable to read and write.

Conclusion:

More than 45% and more than one-third of lactating mothers had poor practice and exposed infants to sunlight for inadequate time, respectively. Therefore, the finding indicates a need for awareness creation to increase women’s knowledge and practice toward the exposure of infants to sunlight.

Burden of Vitamin D, Vitamin B12 and Folic Acid Deficiencies in an Aging, Rural Indian Community

Introduction: The important role of micronutrient deficiencies in aging-related disorders including dementia is becoming increasingly evident. However, information on their burden in India is scarce, especially, among aging and rural communities. Methods: Prevalence of vitamin D, B12 and folic acid deficiency was measured in an ongoing, aging cohort, from rural India-Srinivaspura Aging Neurosenescence and COGnition (SANSCOG) study cohort. Serum level estimation of vitamin D, B12 and folic acid, using chemiluminescence immunoassay, was performed on 1648 subjects (872 males, 776 females). Results: Mean vitamin D, B12 and folic acid levels were 23.4 ± 10.6 ng/ml, 277.4 ± 194.4 pg/ml and 6 ± 3.5 ng/ml), respectively. Prevalence of low vitamin D (<30 ng/ml), vitamin D deficiency (<20 ng/ml), B12 deficiency (<200 pg/ml) and folic acid deficiency (<3 ng/ml) were 75.7, 39.1, 42.3, and 11.1%, respectively. Significantly more women had vitamin D deficiency, whereas more men had folic acid deficiency. Women belonging to the oldest age group (≥75 years) had the maximum burden of low vitamin D (94.3%) and folic acid deficiency (21.8%). Discussion: Older, rural-dwelling Indians have high burden of vitamin D and B12 deficiencies, which is concerning given the potentially negative consequences on cognition, immunity and frailty in the aging population. Urgent public health strategies are needed to address this issue and prevent or mitigate adverse consequences.

Vitamin D status in Hashimoto's thyroiditis and its association with vitamin D receptor genetic variants

BACKGROUND

Hashimoto's thyroiditis (HT) is considered the predominant cause of hypothyroidism in iodine sufficient countries. The deficiency of 25-OH-vitamin D3 serum level and the variation of vitamin D receptor (VDR) gene were implicated in a number of autoimmune disorders. This study aimed to test the hypothesis linking between VDR FokI and BsmI variants and HT, in addition to explain their impact on 25-OH-vitamin D3 serum level.

MATERIALS AND METHODS

Cross sectional study included 160 hypothyroid subjects, 112 patients with HT and 48 hypothyroid non-HT controls. They were diagnosed based on anti-TPO Ab and or anti-TG Ab results. All cases were subjected to full history taking, thyroid ultrasound examination and a panel of assays (TSH, f.T3, f.T4, anti-TPO Ab, anti-TG Ab, calcium, alkaline phosphatase and phosphate). Serum 25-OH-vitamin D3 was assayed using HPLC-UV method. VDR variants (FokI and BsmI) were genotyped using real-time PCR.

RESULTS

FokI AA genotype was statistically higher in HT patients than control group (P value = 0.02) with subsequently higher serum 25-OH-vitamin D3 level in comparison to all other genotypes (P value = 0.039). Serum 25-OH-vitamin D3 level was statistically indifferent between HT and control group (P value = 0.223). A statistically significant increase in total thyroid volume was observed in HT group (P value = 0.002).

CONCLUSION

FokI AA genotype is more associated with HT in Egyptian patients compared to hypothyroid non-HT controls. Moreover, patients with FokI AA genotype have statistically higher levels of 25-OH-vitamin D3 suggesting VDR dysfunction even in patients expressing normal level of vitamin D.

Vitamin D Fortification of Consumption Cow's Milk: Health, Nutritional and Technological Aspects. A Multidisciplinary Lecture of the Recent Scientific Evidence

Vitamin D is essential in assuring bone health at all stages of life, but its non-skeletal effects are also essential: This vitamin impacts the physiology of the immune system, skeletal muscles and adipose tissue, glucose metabolism, skin, cardiovascular and reproductive systems, neuro-cognitive functions and cell division. The incidence of vitamin D deficiency is widespread worldwide, at any age, in young and healthy subjects, as well as in pregnant women and the elderly population, due to several factors, including inadequate sunlight exposure, skin pigmentation and coverage, adiposity, lifestyle and low dietary intakes. To overcome this problem, the fortification of foods that are consumed on a daily basis, such as milk, is strongly advisable. This opinion paper aims to discuss, in a multidisciplinary way, the current evidence supporting the importance of vitamin D in health and disease and the role of milk as an optimal carrier of this vitamin, to promote adequate intakes, highlighting its unique physico-chemical characteristics linked to both fat globule membrane and casein micelle structure. Moreover, it addresses the impact of industrial processing and storage of consumption milk on the stability of these structures, thus in determining vitamin D bioavailability and the achievement of adequate intakes.

Effectiveness and Safety of Thermal Ablation in the Treatment of Primary Hyperparathyroidism: A Multicenter Study

CONTEXT

Ultrasound (US)-guided thermal ablation has generated recent interest as minimally invasive treatments of primary hyperparathyroidism (pHPT). But definitive evidence for the efficacy of thermal ablation in treating pHPT is not well characterized.

OBJECTIVE

This work aims to evaluate the effectiveness and safety of thermal ablation for pHPT.

METHODS

From January 2015 to March 2020, data pertaining to patients who received thermal ablation for pHPT at 4 centers were retrospectively analyzed. The median follow-up duration was 18.1 months (interquartile range, 6.5-42.2 months). A cure referred to the reestablishment of normal values of serum calcium and intact parathyroid hormone throughout the entire follow-up period, at least more than 6 months. The technical success, effectiveness, and safety of treatment were analyzed.

RESULTS

A total of 119 patients (mean age, 57.2 ± 16.3 years; 81 female) with 134 parathyroid nodules were enrolled. The mean maximum diameter of the parathyroid glands was 1.6 ± 0.9 cm. Ninety-six patients underwent microwave ablation (MWA), and 23 patients underwent radiofrequency ablation (RFA). The technical success rate was 98.3% and the cure rate was 89.9%. Significant differences were found in the maximum diameter between the cured patients and the patients who did not undergo ablation of the target lesions. Except for cases with pHPT nodules less than 0.6 cm in diameter, the cure rate was 95%. There were no difference in cure rates at 6 months between the MWA and RFA groups (MWA vs RFA, 90.6% vs 87.0%; χ 2 = 0.275, P = .699). The volume reduction rate of the ablation zone was 94.6% at 12 months. The complication rate was 6.7% (8/119). With the exception of one patient with persistent voice impairment, other symptoms spontaneously resolved within 6 months.

CONCLUSION

Thermal ablation is effective and safe for pHPT.

Vitamin D status and healthy Egyptian adolescents: Where do we stand?

Vitamin D deficiency is a worldwide public health problem. Low vitamin D and its consequences among children and adolescents could be considered as one of the most important health-related problems. This study aimed to estimate the prevalence of vitamin D deficiency in healthy Egyptian adolescents and investigate factors associated with vitamin D status.A cross-sectional study was conducted on 572 school children (270 males and 302 females) aged 14 to 18 years, who were randomly selected from high schools in one governorate in Egypt. Data were collected through a self-administered questionnaire. Vitamin D level, serum calcium, phosphorus, alkaline phosphates were measured.Vitamin D deficiency was almost present in all the studied Egyptian healthy adolescents (99%), 94.8% had vitamin D deficiency and 4.2% had vitamin D insufficiency. Girls had a higher prevalence of vitamin D deficiency than boys. There was a significant association between lack of physical activity, sun exposure, and vitamin D deficiency.Vitamin D deficiency and insufficiency are highly prevalent. In sunny countries, the special pattern of conservative clothing and the lack of outdoor physical activity might be the underlying factors for the high prevalence in females. Vitamin D supplementation seems to be mandatory to halt the problem.

Clinical significance of vitamin D in idiopathic normal pressure hydrocephalus

BACKGROUND

Although recent studies show vitamin D deficiency is associated with cognitive decline, urinary incontinence, and gait instability, there has been no study on the effect of vitamin D on idiopathic normal pressure hydrocephalus (iNPH) characterized by the classic symptom triad of cognitive decline, urinary incontinence, and gait instability. We investigated the clinical significance of vitamin D in patients with iNPH.

METHODS

Between 2017 and 2020, 44 patients who underwent ventriculoperitoneal shunt surgery were divided into low (< 15 ng/mL) and high (≥ 15 ng/mL) vitamin D groups according to the concentration of 25(OH)D, an effective indicator of vitamin D status. They were respectively evaluated according to clinical and radiological findings.

RESULTS

The low vitamin D group (n = 24) showed lower preoperative cognition compared to the high vitamin D group (n = 20) in terms of Korean-Mini Mental Status Examination (K-MMSE) and iNPH grading scale (iNPHGS) (K-MMSE: 20.5 ± 5.4 versus 24.0 ± 4.5, p = 0.041; iNPHGS cognitive score: 2 ± 0.9 versus 1 ± 0.6, p = 0.025). And the low vitamin D group showed pre- and postoperatively more severe urinary incontinence (preoperative iNPHGS urinary score: 1 ± 1.0 versus 0 ± 0.9, p = 0.012; postoperative iNPHGS urinary score:1 ± 1.0 versus 0 ± 0.9, p = 0.014). The score of narrow high-convexity sulci for the low vitamin D group was lower (low vitamin D group: 1 ± 0.7 versus high vitamin D group: 2 ± 0.4, p = 0.031).

CONCLUSION

Lower concentration of vitamin D in iNPH may be related to lower preoperative cognition, pre- and postoperative urinary incontinence, and brain morphological change.

Association of Vitamin D Receptor Gene Polymorphisms with Serum Vitamin D Levels in a Greek Rural Population (Velestino Study)

BACKGROUND/AIM

An alarming increase in vitamin D deficiency even in sunny regions highlights the need for a better understanding of the genetic background of the vitamin D endocrine system and the molecular mechanisms of gene polymorphisms of the vitamin D receptor (VDR). In this study, the serum levels of 25(OH)D3 were correlated with common VDR polymorphisms (ApaI, BsmI, FokI, and TaqI) in 98 subjects of a Greek homogeneous rural population.

METHODS

25(OH)D3 concentration was measured by ultra-HPLC, and the VDR gene polymorphisms were identified by quantitative real-time PCR followed by amplicon high-resolution melting analysis.

RESULTS

Subjects carrying either the B BsmI (OR: 0.52, 95% CI: 0.27-0.99) or t TaqI (OR: 2.06, 95%: 1.06-3.99) allele presented twice the risk for developing vitamin D deficiency compared to the reference allele. Moreover, subjects carrying 1, 2, or all 3 of these genotypes (BB/Bb, Tt/tt, and FF) demonstrated 2-fold (OR: 2.04, 95% CI: 0.42-9.92), 3.6-fold (OR: 3.62, 95% CI: 1.07-12.2), and 7-fold (OR: 6.92, 95% CI: 1.68-28.5) increased risk for low 25(OH)D3 levels, respectively.

CONCLUSIONS

Our findings reveal a cumulative effect of specific VDR gene polymorphisms that may regulate vitamin D concentrations explaining, in part, the paradox of vitamin D deficiency in sunny regions, with important implications for precision medicine.

Socio-Demographic and Knowledge-Related Determinants of Vitamin D Supplementation in the Context of the COVID-19 Pandemic: Assessment of an Educational Intervention

Vitamin D is a pro-hormone, essential for musculo-skeletal health, normal immune system, and numerous other body functions. Vitamin D deficiency is considered as a risk factor in many conditions, and there is growing evidence of its potential role in the severity of COVID-19 outcomes. However, an alarmingly high prevalence of vitamin D deficiency is reported in many regions, and vitamin D supplementation is commonly recommended, particularly during wintertime. To reduce the risk for vitamin D deficiency in the Slovenian population during the COVID-19 pandemic, we conducted mass media intervention with an educational campaign. The objective of this study was to investigate vitamin D supplementation practices in Slovenia before and during the COVID-19 pandemic, and to determine the effects of the educational intervention on supplementation practices. Two data collections were conducted using an online panel with quota sampling for age, sex, and geographical location. A pre-intervention (N = 602, April 2020) and post-intervention (N = 606, December 2020) sampling were done during the first and second COVID-19 lockdown, respectively. We also focused on the identification of different factors connected to vitamin D supplementation, with a particular emphasis on vitamin D-related knowledge. Study results showed significant increase in vitamin D supplementation in the population. Penetration of the supplementation increased from 33% in April to 56% in December 2020. The median daily vitamin D intake in supplement users was 25 μg, with about 95% of supplement users taking safe vitamin D levels below 100 μg/daily. Vitamin D-related knowledge (particularly about dietary sources of vitamin D, the health-related impact of vitamin D, and the prevalence of deficiency) was identified as a key independent predictor of vitamin D supplementation. Based on the study findings, we prepared recommendations to support the development of effective awareness campaigns for increasing supplementation of vitamin D.

The Possible Role of Vitamin D Deficiency in Early Implant Failure

Background. Dental implants are one of the most successful treatments for restoring tooth function and beauty. Identifying the causes of dental implant failure is useful and vital. This review was aimed at studying the possible role of vitamin D in early implant failure. Method and Material. This review was designed based on the PRISMA guideline. Data was collected using keywords including implant, vitamin D, deficiency, failure, dental, OR tooth in international databases including PubMed, Scopus, Web of Science, Cochrane, and Embase, until 2020. Based on the inclusion and exclusion criteria, data were extracted and gathered in a checklist. Results. Finally, twelve studies were selected from five different countries. In 6 studies (2 animal studies and four human studies), there was no significant relationship between vitamin D deficiency and dental implant failure. In the other six studies (1 animal study and five human studies), there was a significant relationship in this regard. Conclusion. It is difficult to conclude the association between vitamin D and implant failure based on the literature’s researches. However, vitamin D appears to play an essential role in implant success through its effects on immune system modulation.

Vitamin D sufficiency attenuates the effect of early social adversity on child antisocial behavior

BACKGROUND

Vitamin D insufficiency and child antisocial behavior are public health concerns. It is unknown whether vitamin D plays a role in antisocial outcomes. This study examines whether higher levels of vitamin D can act as a protective factor against antisocial behavior for children who are exposed to early social adversity.

METHODS

In a community sample of 300 children aged 11-12 years (151 females, 149 males), serum concentrations of 25-hydroxyvitamin D [25(OH)D] were assessed alongside early social adversity, and both parent and child-reported antisocial behavior.

RESULTS

Vitamin D moderated the association between early social adversity and multiple antisocial outcomes. Higher social adversity was associated with greater antisocial behavior among vitamin D-insufficient [25(OH)D < 30 ng/mL], but not vitamin D-sufficient children [25(OH)D ⩾ 30 ng/mL], after adjusting for other variables. Results from child reports of antisocial behavior were replicated with parent reports, providing support for the robustness of the findings. At serum 25(OH)D concentrations above 27.16-30.69 ng/mL (close to 30 ng/mL, the recommended optimal vitamin D level for pediatric populations), the effect of social adversity on antisocial behavior outcomes was nullified.

CONCLUSIONS

To our knowledge, this study is the first to document that a nutritional factor, vitamin D, can potentially confer resilience to antisocial behavior. Our findings in a pediatric population suggest a possible role of vitamin D supplementation in interventions to reduce antisocial behavior, which may be further investigated in future randomized controlled trials.

Seasonal Changes in Vitamin D Levels of Healthy Children in Mid-Latitude, Asian Urban Area

PURPOSE

This study aimed to investigate the seasonal changes in vitamin D levels in a healthy pediatric population living in mid-latitude East Asian urban areas.

METHODS

A pediatric population was selected from single secondary hospital visitors. Clinical data and serum vitamin D levels were collected retrospectively. Statistical analyses were performed based on the month of the blood sampling date, subject age, and vitamin D supplementation history. The data were categorized into three subgroups based on serum vitamin D levels-adequate (≥30 ng/mL), insufficient (20-29 ng/mL), and deficient (<20 ng/mL).

RESULTS

Of the 481 patients, 172 had vitamin D supplementation history. More than 70% of the total study population had inadequate vitamin D levels (<30 ng/mL). The non-supplemented group and the supplemented group showed significantly uneven monthly distribution of the adequate, insufficient, and deficient subgroups. Only the non-supplemented group showed significantly different average vitamin D levels in the summer months compared to the winter months. In the non-supplemented group, vitamin D levels were the lowest in March, the highest in August and September. Significant relevance was noted between vitamin D supplementation status and vitamin D serum level in February and March. There was no significant difference between different age groups in terms of the distribution of vitamin D levels.

CONCLUSION

Currently-widespread vitamin D replacement methods seem to have some effect on increasing the overall serum vitamin D levels, specifically during late winter when natural serum vitamin D levels plunge. However, they are unable to fully compensate the seasonal fluctuation.

Vitamin D and COVID-19: It is time to act

Vitamin D (VitD) deficiency is considered a global problem and might be associated with increased susceptibility to COVID-19 illness. In the light of COVID-19 pandemic, VitD might be a promising agent for fighting the SARS-CoV-2, since VitD is involved in various pathophysiological mechanisms that occur during COVID-19 infection. High-dose VitD supplementation, particularly for risk groups, could be recommended to achieve and maintain optimal (range 40-60 ng/mL) serum 25-hydroxy vitamin D levels (marker of VitD status) both for COVID-19 prevention and treatment.

Potential role of hypovitaminosis D and vitamin D supplementation during COVID-19 pandemic

Vitamin D deficiency is a pandemic disorder affecting over 1 billion of subjects worldwide and displaying a broad spectrum of implications on cardiovascular and inflammatory disorders. Since the initial reports of the association between hypovitaminosis D and COVID-19, Vitamin D has been pointed as a potentially interesting treatment for SARS-CoV-2 infection. We provide an overview on the current status of vitamin D deficiency, the mechanisms of action of vitamin D and the current literature on the topic, with a special focus on the potential implications for COVID-19 pandemic.

In sickness and in health: pivotal role of vitamin D

Within the last several years, frequency of vitamin D testing has multiplied substantially all over the world, since it has been shown to have an important role in many diseases and conditions. Even though liquid chromatography - tandem mass spectrometry (LC-MS/MS) has been identified as "gold standard" method for vitamin D measurement, most laboratories still use immunochemistry methods. Besides analytical problems (hydrophobicity, low circulating concentrations, ability to bind to lipids, albumins and vitamin D binding protein, presence of multiple vitamin D metabolites and variable ratios of 25(OH)D₂ and 25(OH)D₃ in the blood), vitamin D shows great preanalytical variability, since its concentration is drastically influenced by seasonal changes, exposure to sun, type of clothes or sun block creams. Vitamin D is mostly measured in serum or plasma, but new studies are showing importance of measuring vitamin D in pleural effusions, breast milk, urine, synovial fluid and saliva. Besides the main role in calcium homeostasis and bone metabolism, many studies linked vitamin D deficiency with cancer, cardiovascular diseases, diabetes, fertility and many other conditions. However, even though initial observational studies indicated that supplementation with vitamin D might be beneficial in disease development and progression; first results of well-designed randomized controlled prospective studies did not find differences in frequency of cardiovascular events or invasive cancer between patients taking vitamin D supplementation compared to placebo. In the light of these recent findings, validity of excessive vitamin D testing remains an open question.

Physical Determinants of Vitamin D Photosynthesis: A Review

Vitamin D synthesis by exposure of skin to solar ultraviolet radiation (UVR) provides the majority of this hormone that is essential for bone development and maintenance but may be important for many other health outcomes. This process, which is the only well-established benefit of solar UVR exposure, depends on many factors including genetics, age, health, and behavior. However, the most important factor is the quantity and quality of UVR reaching the skin. Vitamin D synthesis specifically requires ultraviolet B (UVB) radiation that is the minority component (<5%) of solar UVR. This waveband is also the most important for the adverse effects of solar exposure. The most obvious of which is sunburn (erythema), but UVB is also the main cause of DNA damage to the skin that is a prerequisite for most skin cancers. UVB at the Earth's surface depends on many physical and temporal factors such as latitude, altitude, season, and weather. Personal, cultural, and behavioral factors are also important. These include skin melanin, clothing, body surface area exposed, holiday habits, and sunscreen use. There is considerable disagreement in the literature about the role of some of these factors, possibly because some studies have been done by researchers with little understanding of photobiology. It can be argued that vitamin D supplementation obviates the need for solar exposure, but many studies have shown little benefit from this approach for a wide range of health outcomes. There is also increasing evidence that such exposure offers health benefits independently of vitamin D: the most important of which is blood-pressure reduction. In any case, public health advice must optimize risk versus benefit for solar exposure. It is fortunate that the individual UVB doses necessary for maintaining optimal vitamin D status are lower than those for sunburn, irrespective of skin melanin. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Serum vitamin D status and metabolic syndrome: a systematic review and dose-response meta-analysis

BACKGROUD/OBJECTIVES

Evidence has suggested an association between serum vitamin D and metabolic syndrome (MetS), but prospective studies are very limited. The objective was to assess the dose-response association between serum vitamin D concentration and MetS risk using a systematic review and meta-analysis of updated observational studies.

MATERIALS/METHODS

Using MEDLINE, PubMed, and Embase, a systematic literature search was conducted through February 2020 and the references of relevant articles were reviewed. A random-effects model was used to estimate the summary odds ratio/relative risk and 95% confidence interval (CI). Heterogeneity among studies was evaluated with I² statistic. In total, 23 observational studies (19 cross-sectional studies, and four cohort studies) were included in the meta-analysis.

RESULTS

The pooled estimates (95% CI) for MetS per 25-nmol/L increment in serum vitamin D concentration were 0.80 (95% CI, 0.76–0.84; I² = 53.5) in cross-sectional studies, and 0.85 (95% CI, 0.72–0.98; I² = 85.8) in cohort studies. Similar results were observed, irrespectively of age of study population, study location, MetS criteria, and adjustment factors. There was no publication bias for the dose-response meta-analysis of serum vitamin D concentrations and MetS.

CONCLUSIONS

Dose-response meta-analysis demonstrated that a 25-nmol/L increment in the serum vitamin D concentration was associated with 20% and 15% lower risks of MetS in cross-sectional studies and cohort studies, respectively.

Effect of Hypovitaminosis D on Lipid Profile in Hypothyroid Patients in Saudi Arabia

BACKGROUND

Hypothyroidism is believed to be associated with dyslipidemia and is considered a risk factor for the development of atherosclerotic cardiovascular diseases (ASCVD). Vitamin D, due to its steroid hormone action, retains cell function and controls the metabolism of lipids. Therefore, the present study was carried out to show the association of the risk factors of ASCVD and deficiency of thyroid hormones and vitamin D levels since no previous studies have been performed on Saudi patients before. Methodology. A retrospective cohort study was carried out on 400 hypothyroid patients. Medical records of those patients were followed up and were classified as normal and hypothyroid patients according to their thyroid-stimulating hormone levels. TSH, vitamin D, and lipid profiles were determined using the ELISA technique.

RESULT

Total cholesterol, triglyceride, and low-density lipoprotein cholesterol levels were significantly higher in hypothyroid patients than those in the normal group. We have found a significant correlation between TSH levels and the risk factors of ASCVD (total cholesterol, triglycerides, and LDL-C). Moreover, a significant correlation between vitamin D levels and the risk factors of ASCVD (total cholesterol, triglycerides, and LDL-C) has been found. In addition, there is a correlation between deficiency of Vit D and low-TSH levels (95% CI 1.092-4.05) indicating a higher risk for the development of ASCVD among those patients.

CONCLUSION

Hypothyroid and vitamin D-deficient patients must be screened regularly at an early stage to predict and also to prevent cardiovascular diseases. Moreover, an adequate supply of vitamin D and TH should be given to those patients to prevent cardiovascular diseases at an early stage.

The Relationship between Low 25-Hydroxyvitamin D and Cardio-Metabolic Risk Factors among Ellisras Young Adults

Introduction: 25-hydroxyvitamin D (25(OH)D) is found in circulating blood and is regarded as an estimate of vitamin D status. Low circulating 25(OH)D levels are associated with a high body mass index (BMI), increased weight and the increased development of adipose tissue. This study aimed to determine the relationship between low 25(OH)D and cardio-metabolic risk factors among Ellisras young adults. Materials and methods: This is a cross-sectional study that took place in a rural area at Ellisras in Limpopo Province South Africa. The study included 631 young adults (327 females and 304 males) aged between 20 and 29 years. Anthropometric measurements including height, weight and waist circumference were measured following standard procedures. Blood pressure, pulse pressure and blood parameters including fasting plasma glucose, total cholesterol and triglycerides were also measured. Correlations and linear regression were performed to determine the relationship between low 25(OH)D and cardio-metabolic risk factors. Results: Descriptive statistics showed significant (p < 0.05) mean difference of LDL, HDL and blood pressure between males and females. There was a significant association between low 25(OH)D and WC (p = 0.010) based on Spearman correlation. There was no association found between low 25(OH)D and HDL in all models (B ranges from 0.072 to 0.075). There was also no association found between low 25(OH)D and systolic blood pressure (SBP) in all models (B ranges from −0.009 to −0.024). Conclusion: Low 25(OH)D was correlated with WC, and therefore with adiposity. Knowledge of the associations between 25(OH)D deficiency and cardio-metabolic risk before the development of the disease is therefore important to establish whether 25(OH)D supplementation can be used for the prevention of these conditions. Educational programmes should be implemented to educate the communities and the nation at large on how to prevent 25(OH)D deficiency.