Predicting vitamin D deficiency using optimized random forest classifier.

BACKGROUND: Vitamin D can be acquired from various dietary sources, but exposure to sunlight's ultraviolet rays can convert a natural compound called ergosterol present in the skin into vitamin D. AIM: The current study aimed to investigate vital parameters and use an optimized random forest (OptRF) classifier to understand better and predict the effect of environmental and nutritional factors of Vitamin D deficiency. METHODS: A predictive, cross-sectional, and correlational design was utilized in a study involving 350 male and female Tabuk citizens in Saudi Arabia. The Weka machine-learning tool was employed for comprehensive data analysis, with the OptRF algorithm being tailored through advanced feature selection methods and meticulous hyperparameter tuning. RESULTS: In addition to the OptRF classifier, a number of traditional machine learning techniques have been tested and compared on the dataset of vitamin D to analyze and build the predictive model for classifying vitamin D deficiency. In general, the OptRF-based predictive model can statistically describe data for determining significant features related to Vitamin D deficiency. OptRF demonstrated its ability to classify vitamin D deficiency cases with high accuracy 91.42 %. CONCLUSION: This study showed that Tabuk citizens are at high risk of vitamin D deficiency especially among females (gender predictor) with little regard to age, income, smoking, and sun exposure. In addition, exercise, less Vitamin D intake, and less intake of Calcium are also predictors of Vitamin D deficiency. Due to the link between Vitamin D Deficiency and major chronic illnesses, it is important to emphasize the importance of identifying risk factors and screening for Vitamin D Deficiency. It may be appropriate for nutritionists, nurses, and physicians to promote community awareness about strategies to improve dietary Vitamin D intake or consider recommending supplements.

High Incidence of Vitamin D Deficiency (VDD) Among Indoor Workers: Association with Dietary and Lifestyle Factors.

The study evaluated the relationship of various dietary and lifestyle factors with vitamin D status and bone health of adults engaged in office jobs. A total of 100 subjects comprising of 50 males and 50 females (with their willingness to participate) in the age group of 30-50 years were purposively selected for the investigation, who were spending 8 hours in the offices. Results showed that most of the subjects had vitamin D deficit with mean serum vitamin D level as 13.2 ng/ml and 68% were osteopenic. Dietary phytates, sedentary lifestyle, higher body mass index were found to have a deleterious impact on vitamin D status. This silent epidemic needs to be addressed with effective public health initiatives, such as raising awareness about the availability of fortified foods, optimum time, and body surface area for sun exposure.

Vitamin Supplement Use in Patients With CKD: Worth the Pill Burden?

All vitamins play essential roles in various aspects of body function and systems. Patients with chronic kidney disease (CKD), including those receiving dialysis, may be at increased risk of developing vitamin deficiencies due to anorexia, poor dietary intake, protein energy wasting, restricted diet, dialysis loss, or inadequate sun exposure for vitamin D. However, clinical manifestations of most vitamin deficiencies are usually subtle or undetected in this population. Testing for circulating levels is not undertaken for most vitamins except folate, B12, and 25-hydroxyvitamin D because assays may not be available or may be costly to perform and do not always correlate with body stores. The last systematic review through 2016 was performed for the Kidney Disease Outcome Quality Initiative (KDOQI) 2020 Nutrition Guideline update, so this article summarizes the more recent evidence. We review the use of vitamins supplementation in the CKD population. To date there have been no randomized trials to support the benefits of any vitamin supplementation for kidney, cardiovascular, or patient-centered outcomes. The decision to supplement water-soluble vitamins should be individualized, taking account the patient's dietary intake, nutritional status, risk of vitamins deficiency/insufficiency, CKD stage, comorbid status, and dialysis loss. Nutritional vitamin D deficiency should be corrected, but the supplementation dose and formulation need to be personalized, taking into consideration the degree of 25-hydroxyvitamin D deficiency, parathyroid hormone levels, CKD stage, and local formulation. Routine supplementation of vitamins A and E is not supported due to potential toxicity. Although more trial data are required to elucidate the roles of vitamin supplementation, all patients with CKD should undergo periodic assessment of dietary intake and aim to receive various vitamins through natural food sources and a healthy eating pattern that includes vitamin-dense foods.

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial.

OBJECTIVE: Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis. DESIGN: Pilot, prospective, open-label randomised controlled trial. SETTING: Peking University First Hospital, China. PARTICIPANTS: Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020. INTERVENTIONS: Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis. RESULTS: Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon. CONCLUSIONS: A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

Vitamin D knowledge, awareness and practices of female students in the Southwest of Saudi Arabia: A cross-sectional study.

Vitamin D deficiency is a common health problem among adults in Saudi Arabia, particularly females. Vitamin D deficiency is associated with many diseases, including cardiovascular diseases, diabetes, autoimmune diseases, neurological disorders, and cognitive decline. This study aimed to assess the knowledge, awareness and practice of vitamin D deficiency among female students in Jazan University as well as to determine the sociodemographic related factors. A cross-sectional study was conducted among 204 female undergraduate and postgraduate students (18 years of age and older) in March 2022 from Saudi Arabia. Students completed a web-based survey about vitamin D and their demographic characteristics. Statistical analyses were conducted using Statistical Package for the Social Sciences software. Descriptive statistics, the Chi-squared test of homogeneity, and univariate and multivariate logistic regression were used. The results revealed that the participants had limited knowledge related to vitamin D normal level (49.5%), and the recommended daily amount of vitamin D (26.5%). Most of the participants were unaware of its benefits for vision, muscle integrity, weakness, and fatigue. Most of them recognized the importance of sunlight for maintaining suitable levels of vitamin D (94.1%). However, only 43.1% identified that decreased intake of foods rich in vitamin D is a cause of vitamin D deficiency. Participants (33.7%) preferred exposure to sunlight to improve their vita-min D levels, and 32.4% used vitamin D supplements. However, only 39.2% had ever examined their vitamin D status. Univariate and multivariate logistic regression models demonstrated a significant association between knowledge, and residence, and source of information (odds ratios = 3.48 and 2.79, respectively, P < .05). Most respondents had a basic understanding of vitamin D, vitamin D insufficiency, and the environmental and dietary factors contributing to it. Given the findings obtained, cognitive interventions need to be carried out.

Trabajo a turnos y Vitamina D / Could serum Vitamin D levels be altered when working shifts?

Este trabajo es un comentario del artículo: Martelli M, Salvio G, Santarelli L, Bracci M. Shift Work and Serum Vitamin D Levels: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2022 Jul 22;19(15):8919. doi: 10.3390/ijerph19158919 (AU)

This text is a commentary on the article: Martelli M, Salvio G, Santarelli L, Bracci M. Shift Work and Serum Vitamin D Levels: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2022 Jul 22;19(15):8919. doi: 10.3390/ijerph19158919 (AU)

Vitamin D status and supplementation before and after Bariatric Surgery: Recommendations based on a systematic review and meta-analysis.

Bariatric surgery is associated with a postoperative reduction of 25(OH) vitamin D levels (25(OH)D) and with skeletal complications. Currently, guidelines for 25(OH)D assessment and vitamin D supplementation in bariatric patients, pre- and post-surgery, are still lacking. The aim of this work is to analyse systematically the published experience on 25(OH)D status and vitamin D supplementation, pre- and post-surgery, and to propose, on this basis, recommendations for management. Preoperatively, 18 studies including 2,869 patients were evaluated. Prevalence of vitamin D insufficiency as defined by 25(OH)D < 30 ng/mL (75 nmol/L) was 85%, whereas when defined by 25(OH)D < 20 ng/mL (50 nmol/L) was 57%. The median preoperative 25(OH)D level was 19.75 ng/mL. After surgery, 39 studies including 5,296 patients were analysed and among those undergoing either malabsorptive or restrictive procedures, a lower rate of vitamin D insufficiency and higher 25(OH)D levels postoperatively were observed in patients treated with high-dose oral vitamin D supplementation, defined as ≥ 2,000 IU/daily (mostly D3-formulation), compared with low-doses (< 2,000 IU/daily). Our recommendations based on this systematic review and meta-analysis should help clinical practice in the assessment and management of vitamin D status before and after bariatric surgery. Assessment of vitamin D should be performed pre- and postoperatively in all patients undergoing bariatric surgery. Regardless of the type of procedure, high-dose supplementation is recommended in patients after bariatric surgery.

Prevalence and associated factors of vitamin D deficiency after Roux-en-Y gastric bypass: a systematic review and meta-analysis.

OBJECTS: To estimate the prevalence and associated factors of vitamin D deficiency (VDD) after Roux-en-Y gastric bypass (RYGB). METHODS: PubMed, EMBASE, and CENTRAL were searched for relevant records from inception to 17 March 2023, using search terms: vitamin D, vitamin D3, vitamin D deficiency, hypovitaminosis D, gastric bypass, and RYGB. Studies were eligible for inclusion if they provided related data on VDD prevalence after RYGB. RESULTS: Of the 1119 screened studies, 72 studies involving 7688 individuals were enrolled in the final analysis. The prevalence estimates of VDD after RYGB were 42%. Subgroup analyses suggested the pooled prevalence of postoperative VDD was 35% for follow-up duration less than or equal to 1 year, 43% for greater than 1 and less than or equal to 5 years, and 54% for greater than 5 years. Meta-regression showed that VDD prevalence was positively correlated with follow-up time. Also, the prevalence was higher in studies with inadequate vitamin D supplementation than in those with adequate supplementation and in Asia population than in those from South America, Europe, and North America. Other factors associated with high VDD prevalence after RYGB included high presurgical VDD prevalence, noncompliant patients, and black populations. No significant association existed between VDD and alimentary length. CONCLUSION: VDD presented a high prevalence in patients following RYGB. It occurred more frequently with longer postoperative follow-up time. Population-specific vitamin D supplementation measures, targeted treatment for presurgical VDD, improved patient compliance, and periodical follow-ups were necessary to reduce VDD and other adverse outcomes.

Evaluation of vitamin D levels and affecting factors of vitamin D deficiency in healthy children 0-18 years old.

The frequency of vitamin D deficiency in healthy children is relatively high. Moreover, vitamin D supplementation in children is under the requested levels. The aim of this study is to determine the frequency of vitamin D deficiency and the factors that influence vitamin D levels in healthy children. During the study period, 3368 vitamin D levels of healthy children, aged 0-18 years, were evaluated retrospectively. Vitamin D levels were categorized as deficiency (< 12 ng/ml), insufficiency (12-20 ng/ml), and sufficiency (> 20 ng/ml). The prevalence of vitamin D deficiency and insufficiency was found to be 18-24.9% in healthy children, respectively. It was found that the frequency of vitamin D deficiency increased with age. In addition, the most severe and highest risk group for vitamin D deficiency were adolescent girls. Moreover, being in the winter or spring season and living in the north of the 40th parallel are the other risk factors for vitamin D deficiency. CONCLUSION:  This study showed that vitamin D deficiency still remains a major problem for healthy children and daily supplementation of vitamin D is mandatory. Prophylactic vitamin D supplementation and adequate sunlight exposure should be provided for all children, in particular healthy adolescents. In addition, future studies may focus on screening for vitamin D status in children who did not receive vitamin D supplementation. WHAT IS KNOWN: • Vitamin D is an essential component in bone metabolism. Seasonality, age, sex, dark skin pigmentation, and limited exposure to sunlight are causes of vitamin D deficiency. • The World Health Organization has drawn attention to this increased frequency, recommending lifelong, regular vitamin D prophylaxis. WHAT IS NEW: • The frequency of vitamin D deficiency and insufficiency was found to be 42.9% in healthy children and the frequency significantly increased with age. • There were almost no cases of prophylactic vitamin D usage in adolescent group which are at the highest risk.

Determination of a Serum 25-Hydroxyvitamin D Reference Ranges in Japanese Adults Using Fully Automated Liquid Chromatography-Tandem Mass Spectrometry.

BACKGROUND: Despite an increasing interest in vitamin D status, a reference range of the nutrient has not been fully established. This is partly due to a paucity of standardized measuring systems with high throughput. In addition, the range may vary by populations and may change with modernization of lifestyles. OBJECTIVES: This study aims to calculate the current reference concentration of 25-hydroxyvitamin D (25(OH)D) among healthy people living in an urban area in Japan. METHODS: A newly developed fully automated liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) system was used to measure serum 25(OH)D concentrations. Reproducibility was assessed by measuring standardized samples. Accuracy was validated by comparing with commercially available immunoassays. Then, mass screening was conducted targeting participants who received medical checkups in Tokyo from April 2019 to March 2020, and the reference ranges were calculated. RESULTS: The coefficients of variations of interoperator and interday reproducibility were 4.1%-8.5% and 3.7%-8.0% for 25-hydroxyvitamin D2 (25(OH)D2) and 4.7%-7.0% and 4.0%-6.9% for 25-hydroxyvitamine D3, respectively. The measured total 25(OH)D concentrations correlated well with those measured by immunoassays. In total, 5518 participants were measured for 25(OH)D concentrations, among whom 98% showed inadequate concentrations (<30 ng/mL). The reference ranges of total 25(OH)D for female, male, and total participants were 7-30 ng/mL, 5-27 ng/mL, and 6-29 ng/mL, respectively. After excluding those with abnormal renal and liver function, the range was 6-30 ng/mL. CONCLUSIONS: The high prevalence of vitamin D insufficiency among seemingly healthy population may be attributed to lifestyle characteristics of people living in urban areas of Japan, including spending less time outdoors and lower intake of traditional foods. Longitudinal follow-up and mass screenings targeting different population will help elucidate reasons for discrepancies between official guidelines and the observed concentrations, to which the well-validated measurement system is essential.

Optimal 25-OH-Vitamin D Level in Children Derived From Biochemical Parameters.

The aim of the study was to evaluate the bone-optimal pediatric levels of 25-hydroxy-vitamin D (25OHD) by testing the level at which 25OHD optimally effects calcium, phosphorus, and parathyroid hormone levels in a large population-based dataset. This was an observational retrospective "big-data" study. We analyzed 49 935 25OHD tests from children sampled in Clalit Health Services, Jerusalem district between 2009 and 2019. Associated data were available in the following number of samples: corrected calcium; 18 869, phosphorus: 1241, and PTH: 449. We tested correlations between each parameter and 25OHD, adjusting phosphorus levels by age using a "phosphorus index". Pearson's and Spearman's correlation coefficients were calculated to determine the strength of the correlation between 25OHD and each parameter. There was a significant correlation between 25OHD levels and both PTH and calcium but not for the phosphorus index. The level at which increase in 25OHD continued to cause significant alteration was: for PTH up to 100 nmol/l (40 ng/ml), for corrected calcium it increased beyond 100 nmol/l. Increasing levels of 25OHD levels up to at least 100 nmol/l are associated with improvement in parameters known to be associated with increased bone mineralization. Therefore, one should aim for a 25OHD level of 100 nmo/l.

Vitamin d levels and lipid profile in patients undergoing bariatric surgery / Níveis de vitamina d e perfil lipídico em pacientes submetidos à cirurgia bariátrica

ABSTRACT BACKGROUND: Vitamin, mineral, and metabolic deficiencies occur in the postoperative period of bariatric surgery, in the short and long term, and are worrisome intercurrences. AIMS: To evaluate the association of serum vitamin D levels with the lipid profile in obese patients undergoing bariatric surgery. METHODS: Case series of patients assisted from 2010 to 2018, in a private hospital of medium and high complexity, who underwent bariatric surgery using sleeve gastrectomy or Roux-en-Y gastric bypass techniques, monitored by the same surgeon. Sociodemographic, clinical, laboratory, and anthropometric data were collected preoperatively and at 6, 12, and 24 months after surgery. RESULTS: A total of 156 individuals, mostly female (75.6%) were monitored. The most frequent comorbidities were hepatic steatosis (76.3%) and hypertension (48.27). Regarding preoperative vitamin D levels, only 18.9% of the population had a satisfactory level (≥30 ng/mL). There was a reduction in weight and an improvement in the lipid profile after surgery. Significant correlations were observed between the lipid profile and vitamin D concentration only in the sample submitted to the Roux-en-Y gastric bypass technique: negative correlation between total cholesterol and vitamin D two years after surgery; positive correlation between triglycerides and vitamin D one year after surgery; and negative correlation between high-density lipoprotein and vitamin D two years post-surgery. CONCLUSIONS: It is essential to routinely monitor vitamin D levels and lipid profile pre- and postoperatively in order to avoid damage associated with this vitamin deficiency.

RESUMO RACIONAL: Deficiências vitamínicas, minerais e metabólicas ocorrem no pós-operatório de cirurgia bariátrica, a curto e longo prazo, sendo intercorrências preocupantes. OBJETIVOS: Avaliar a associação dos níveis séricos de vitamina D com o perfil lipídico, em pacientes obesos submetidos à cirurgia bariátrica. MÉTODOS: Série de casos de pacientes atendidos de 2010 até 2018, em hospital privado de média e alta complexidade, submetidos à cirurgia bariátrica pelas técnicas da gastrectomia vertical e derivação gástrica em Y de Roux, acompanhados pelo mesmo cirurgião. Foram coletados dados sociodemográficos, clínicos, dados laboratoriais e antropométricos no pré-operatório, 6 meses, 12 meses e 24 meses após cirurgia. RESULTADOS: Foram acompanhados 156 indivíduos, maioria sexo feminino (75,6%), comorbidades mais frequentes foram esteatose hepática (76,3%) e hipertensão (48,27). Em relação aos níveis de vitamina D pré-operatórios, apenas 18,9% da população apresentaram níveis satisfatórios (=30 ng/mL). Observou-se redução do peso e melhora do perfil lipídico pós-cirúrgico. Sobre as correlações entre o perfil lipídico e concentração de vitamina D foram observadas correlações significativas apenas na amostra que passou pela técnica cirúrgica derivação gástrica em Y de Roux: correlação negativa entre o colesterol total e vitamina D após 2 anos de cirurgia; correlação positiva entre triglicerídeo e vitamina D 1 ano pós-operatório; e correlação negativa entre HDL e vitamina D 2 anos pós-operatório. CONCLUSÕES: é essencial acompanhar os níveis de vitamina D e perfil lipídico no pré e pós-operatório de forma rotineira a fim de evitar danos relacionados a deficiência dessa vitamina.

Maternal Vitamin D Status and Its Associated Environmental Factors: A Cross-Sectional Study.

Background: Vitamin D deficiency is common among women during pregnancy. This study aims to determine the prevalence of vitamin D deficiency and their shared modifiable environmental factors among pregnant women in Indonesia and Malaysia. Methods: Blood samples of 844 third-trimester pregnant women (Indonesians: 311; Malaysians: 533) were collected to determine their serum 25(OH) D levels. Information on sun exposure and sun protection behaviours were obtained through face-to-face interviews. Dietary vitamin D intake was assessed by using a semiquantitative food frequency questionnaire. Results: The prevalence of vitamin D deficiency (<30 nmol/L) among Indonesian and Malaysian pregnant women were 42.4% and 72.0%, respectively. Percentage of exposed body surface area was inversely associated with vitamin D deficiency among Indonesian pregnant women (OR = 0.21, 95% CI = 0.09-0.48). Among Malaysian pregnant women, higher intakes of dietary vitamin D were associated with lower risk of vitamin D deficiency (OR = 0.48, 95% CI = 0.29-0.81). Analysis of the combined cohorts revealed a lower risk of vitamin D deficiency among pregnant women who had a daily intake of at least 15 mcg vitamin D (OR = 0.58, 95% CI = 0.38-0.88) and exposure of more than 27% body surface area to the sunlight (OR = 0.30, 95% CI = 0.16-0.60). Conclusions: Despite abundant sunshine, vitamin D deficiency is prevalent among pregnant women in tropical countries. The present study suggests that nutrition education on vitamin D intake and sun exposure during pregnancy is necessary for primary prevention of vitamin D deficiency in pregnant women living in the tropical countries.

VITAMIN D AND OPHTHALMOPATHIAS. A REVIEW.

The importance of vitamin D3 (hydroxycholecalciferol) as one of the liposoluble vitamins is known in the prevention and treatment of metabolic bone diseases (rickets, osteomalacia, osteoporosis). In recent years, however, information has increased on the importance of vitamin D3 in numerous organ systems and in the pathogenesis of various diseases, e. g. ophthalmopathies. The immunological functions of vitamin D3 are the subject of studies dealing with autoimmune optic nerve disorders and their results appear to have a positive effect on demyelinating diseases. It also plays an important role in maintaining the thickness of the retinal nerve fiber layer, but its additional administration has not been successful. Optical neuritis may be the first sign of multiple sclerosis. It appears that sufficient serum vitamin D3 levels may protect patients from deterioration in the form of a further attack of demyelination. The course of diabetic retinopathy is probably also influenced by vitamin D3, inter alia, by correlating the fact that its receptor and the enzymes of its metabolism are expressed on the retina. Low serum levels of vitamin D3 may even trigger age-related macular degeneration. Conversely, higher dietary intake of vitamin D3 may positively affect neovascularization. The optimal level of hydroxycholecalciferol is between 60 and 200 nmol /l, the severe deficit represents a decrease below 25 nmol/l. The body can normally produce up to 10,000 IU of this vitamin after exposure to sunlight. However, the demonstration of its protective character in connection with the mentioned diseases of the retina and optic nerve will require a sufficient number of studies to confirm the facts found so far about this rediscovered vitamin.

Severe Vitamin D Deficiency in Youth with Autism Spectrum Disorder During the COVID-19 Pandemic.

BACKGROUND: Decrease in sunlight exposure during periods of social distancing during the COVID-19 pandemic increased the risk of severe manifestations of vitamin D deficiency (VDD) in a particular "high-risk" population. Our objective was to highlight the importance of vitamin D screening in youth with autism spectrum disorder (ASD) and restrictive eating. CASE PRESENTATION: We describe 3 adolescent male patients with ASD who developed severe manifestations of VDD and hypocalcemia in late 2020 during the COVID-19 pandemic. All spent less time outdoors than in prior years because of isolation at home during the pandemic. Presenting symptoms included seizures and atraumatic fractures. All 3 were found to have hypocalcemia and severe VDD. Limited sun exposure because of isolation indoors during the COVID-19 pandemic was a likely contributing factor to the severity of VDD. All 3 were treated with intravenous calcium acutely, followed by oral calcium and vitamin D. Laboratory tests performed post-treatment showed biochemical resolution of hypocalcemia and VDD. CONCLUSION: These cases highlight the importance of screening "at-risk" youth for VDD. Clinicians should be cognizant that children and adolescents with ASD and restricted eating can have severe manifestations of hypocalcemia and VDD. Decreased sun exposure because of isolating indoors during the COVID-19 pandemic increased their risk for this.

How Vitamin D Levels of Children Changed During COVID-19 Pandemic: A Comparison of Pre-pandemic and Pandemic Periods

Objective: The synthesis of vitamin D is related to sun exposure, thus the restrictions during the Coronavirus disease-2019 (COVID-19) pandemic may have affected the levels of vitamin D in all age groups. The aim of this study was to evaluate vitamin D levels of healthy children and adolescents during the first year of the pandemic. Methods: The study group included healthy children and adolescents who were admitted for general check-ups and evaluated with 25(OH)D levels. Then, it was divided into two groups: Group 1 "pre-pandemic", and Group 2 "pandemic". Vitamin D levels were recorded from the hospital database and were compared according to age groups, gender, and the season, retrospectively. Results: The study group [mean age=90.29±59.45 median age=79 interquartile range (IQR): 102 months, male/female: 1409/1624] included 3033 children and adolescents (Group 1/Group 2 n=1864/1169). Although the mean 25(OH)D levels among preschool children did not differ between groups, the vitamin D levels of school-aged children and adolescents were significantly lower in the pandemic period than in the pre-pandemic period [Group 1 median=16.50 (IQR: 10.5) vs Group 2 median=15.9 (IQR: 11.3) in 6-12 age group (p=0.026); Group 1 median=13.30 (IQR: 10.2) vs Group 2 median=11.20 (IQR: 9.7) in 12-18 age group (p=0.003)]. Moreover, the 25(OH)D levels of adolescents showed seasonal variance with lower levels in winter, and unexpectedly, in summer. Conclusion: Pandemic-related restrictions have caused significant decreases in vitamin D levels of school-aged children and adolescents. We suggest that children and adolescents should be given vitamin D supplementation in order to maintain sufficient levels of vitamin D during the pandemic.

Preeclampsia at delivery is associated with lower serum vitamin D and higher antiangiogenic factors: a case control study.

BACKGROUND: Preeclampsia is characterized by decreased trophoblastic angiogenesis leading to abnormal invasion of spiral arteries, shallow implantation and resulting in compromised placentation with poor uteroplacental perfusion. Vitamin D plays an important role in pregnancy influencing implantation, angiogenesis and placental development. The objective of this study was to determine whether there is an association between serum vitamin D levels, and anti-angiogenic factors at the time of delivery and the occurrence of preeclampsia. METHODS: This nested case control study analyzed frozen serum samples at the time of delivery and related clinical data from women with singleton liveborn pregnancies who had participated in studies of the NICHD Stillbirth Collaborative Research Network. Women with a recorded finding of preeclampsia and who had received magnesium sulfate treatment prior to delivery were considered index cases (N = 56). Women without a finding of preeclampsia were controls (N = 341). RESULTS: Women with preeclampsia had 14.5% lower serum vitamin D levels than women in the control group (16.5 ng/ml vs. 19 ng/ml, p = 0.014) with 64.5% higher sFlt-1 levels (11,600 pg/ml vs. 7050 pg/ml, p < 0.001) and greater than 2 times higher endoglin levels (18.6 ng/ml vs. 8.7 ng/ml, < 0.001). After controlling for gestational age at delivery and maternal BMI, vitamin D levels were 0.88 times lower (P = 0.051), while endoglin levels were 2.5 times higher and sFlt-1 levels were 2.1 times higher than in control pregnancies (P < 0.001). CONCLUSIONS: Women with preeclampsia at time of delivery have higher maternal antiangiogenetic factors and may have lower maternal serum vitamin D levels. These findings may lead to a better understanding of the underlying etiology of preeclampsia as well as possible modifiable treatment options which could include assuring adequate levels of maternal serum vitamin D prior to pregnancy.

The Role of Vitamin D in Diabetic Nephropathy: A Translational Approach.

According to several animal and human studies, vitamin D appears to play a significant role in the development of diabetic nephropathy. However, the possible renoprotective effect of vitamin D and its influence on the reversal of already existing renal damage remains doubtful. At this moment, there are a few hypotheses concerning the underlying molecular and genetic mechanisms including the link between vitamin D and inflammation, oxidative stress, and extracellular matrix accumulation. The present review aims to investigate the potential role of vitamin D in the development of diabetic kidney disease from a translational approach.

Vitamin D status among Kashmiri tribal population: A cross-sectional community-based study.

Background & objectives: Vitamin D deficiency (VDD) is prevalent across all age groups in general population of India but studies among tribal populations are scanty. This study aimed to evaluate the prevalence of VDD in the indigenous tribal population of the Kashmir valley and examine associated risk factors. Methods: In this cross-sectional investigation, a total of 1732 apparently healthy tribal participants (n=786 males and n=946 females) were sampled from five districts of Kashmir valley by using probability proportional to size method. Serum 25-hydroxy vitamin D (25(OH)D) levels were classified as per the Endocrine Society (ES) recommendations: deficiency (<20 ng/ml), insufficiency (20-30 ng/ml) and sufficiency (>30 ng/ml). The serum 25(OH)D levels were assessed in relation to various demographic characteristics such as age, sex, education, smoking, sun exposure, body mass index and physical activity. Results: The mean age of the male participants was 43.79±18.47 yr with a mean body mass index (BMI) of 20.50±7.53 kg/m[2], while the mean age of female participants was 35.47±14.92 yr with mean BMI of 22.24±4.73 kg/m2. As per the ES guidelines 1143 of 1732 (66%) subjects had VDD, 254 (14.71%) had insufficient and 334 (19.3%) had sufficient serum 25(OH)D levels. VDD was equally prevalent in male and female participants. Serum 25(OH)D levels correlated positively with serum calcium, phosphorous and negatively with serum alkaline phosphatase. Gender, sun exposure, altitude, physical activity and BMI did not seem to contribute significantly to VDD risk. Interpretation & conclusions: VD deficiency is highly prevalent among Kashmiri tribals, although the magnitude seems to be lower as compared to the general population. These preliminary data are likely to pave way for further studies analyzing the impact of vitamin D supplementation with analysis of functional outcomes.

Vitamin D status in children and adolescents with type 1 diabetes in a specialized diabetes care centre in Bangladesh.

OBJECTIVES: High prevalence of vitamin D deficiency (VDD) in children and adolescents with type 1 diabetes (T1D) was found in several epidemiological studies. The current study aimed to assess the Vitamin D status in children and adolescents with T1D and to examine the influence of the disease characteristics on vitamin D status in a specialized care centre in a tertiary hospital in Bangladesh. METHODS: Participants were enrolled in the cross-sectional study at the time of a regularly scheduled visit to the CDiC Paediatric Diabetes Center in BIRDEM 2(Bangladesh Institute of Research and Rehabilitation of Diabetes Endocrine and Metabolic Disorders), a tertiary care hospital in Bangladesh. The demographic and clinical data were collected through medical records with a structured questionnaire. RESULTS: Among sixty study participants, most had inadequate levels of vitamin D: deficiency 31 (51.7%), insufficiency 14 (23.3%) and sufficiency 15 (25.0%). Participants with vitamin D deficiency (VDD) were significantly older compared to the sufficient and insufficient group (p = .029), and were residing in urban areas (p = .036) and from higher socioeconomic status (p = .014). BMI was significantly higher in VDD compared to the sufficient group (p = .040). Although we observed higher median values of daily insulin requirements and HbA1c values in patients with VDD compared to patients with vitamin D insufficiency or vitamin D sufficiency, these differences did not reach statistical significance. CONCLUSIONS: The present study revealed that the prevalence of vitamin D deficiency and insufficiency among T1 diabetes children was very high. Future studies in large sample are required to assess hypovitaminosis D in youth with T1D and also the possible relating factors of vitamin D deficiency.