Prevalence of Vitamin D deficiency in the North-West region of Russia: A cross-sectional study

Vitamin D-The Iceberg in Endometriosis-Review and Meta-Analysis

(1) Background: Although vitamin D has many known biological effects, very little research has been conducted on how vitamin D may be related or play a role in endometriosis. The aim of our study was to perform an evaluation regarding vitamin D levels and possible implications in endometriosis through a statistical analysis of the data collected from the included studies. (2) Methods: For this review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, and PubMed/Internet portal of the National Library of Medicine databases using several keywords related to our topic. (3) Results: Only nine articles were identified as complete or possessing the capacity to compute all available data. We totalized a number of 976 patients with endometriosis and 674 controls. From the nine studies included in our analysis, three of them claim there is no difference between women with and without endometriosis concerning 25(OH) vitamin D levels; however, the other six studies found significant differences regarding this aspect. (4) Conclusions: Our results underscored the complexity of analyzing the role of the vitamin D complex in a challenging condition like endometriosis and suggest that focusing on the tissue level might be essential to obtain accurate answers to our inquiries.

Low vitamin D levels among children and adolescents in an Arctic population

AIMS

We aimed to study the vitamin D status of the population of Arkhangelsk, a city in northwestern Russia.

METHODS

A cross-sectional study was conducted to estimate serum 25(OH)D concentrations in Arkhangelsk residents, including 55 neonates and their mothers, 214 children <3 years, 191 schoolchildren (7-8 years), 403 adolescents (13-17 years), 260 university students (18-22 years) and 85 adults (24-60 years). The data were collected from March 2013 to November 2014 and from January 2016 to May 2016.

RESULTS

Normal levels of 25(OH)D (>30 ng/ml) were found in 5% of neonates, 43% of their mothers, 43% of children <3 years, 9% of schoolchildren, 1% of adolescents, 17% of students and 26% of adults. There was a moderate positive correlation (rs = 0.563, p = 0.001) between 25(OH)D levels in mother's blood and umbilical cord blood.

CONCLUSIONS

Vitamin D deficiency is highly prevalent in the population of Arkhangelsk, particularly in neonates, schoolchildren and adolescents.

Vitamin D Status and Gestational Diabetes in Russian Pregnant Women in the Period between 2012 and 2021: A Nested Case-Control Study

Several meta-analyses found an association between low maternal serum 25-hydroxyvitamin D (25(OH)D) level and gestational diabetes mellitus (GDM). However, some of them reported significant heterogeneity. We examined the association of serum 25(OH)D concentration measured in the first and in the second halves of pregnancy with the development of GDM in Russian women surveyed in the periods of 2012−2014 and 2018−2021. We conducted a case−control study (including 318 pregnant women) nested on two previous studies. In 2012−2014, a total of 214 women (83 GDM and 131 controls) were enrolled before 15 weeks of gestation and maternal serum 25(OH)D concentrations were measured twice: at 8th−14th week of gestation and simultaneously with two-hour 75 g oral glucose tolerance test (OGTT) at 24th−32nd week of gestation. In the period of 2018−2021, 104 women (56 GDM and 48 controls) were included after OGTT and 25(OH)D concentrations were measured at 24th−32nd week of gestation. Median 25(OH)D levels were 20.0 [15.1−25.7] vs. 20.5 [14.5−27.5] ng/mL (p = 0.565) in GDM and control group in the first half of pregnancy and 25.3 [19.8−33.0] vs. 26.7 [20.8−36.8] ng/mL (p = 0.471) in the second half of pregnancy, respectively. The prevalence rates for vitamin D deficiency (25(OH)D levels < 20 ng/mL) were 49.4% and 45.8% (p = 0.608) in the first half of pregnancy and 26.2% vs. 22.1% (p = 0.516) in the second half of pregnancy in women who developed GDM and in women without GDM, respectively. The frequency of vitamin D supplements intake during pregnancy increased in 2018−2021 compared to 2012−2014 (p = 0.001). However, the third trimester 25(OH)D levels and prevalence of vitamin D deficiency (25.5 vs. 23.1, p = 0.744) did not differ in women examined in the periods of 2012−2014 and 2018−2021. To conclude, there was no association between gestational diabetes risk and maternal 25(OH)D measured both in the first and in the second halves of pregnancy. The increased prevalence of vitamin D supplements intake during pregnancy by 2018−2021 did not lead to higher levels of 25(OH)D.

Vitamin D Intake May Reduce SARS-CoV-2 Infection Morbidity in Health Care Workers

In the last 2 years, observational studies have shown that a low 25-hydroxyvitamin D (25(OH)D) level affected the severity of infection with the novel coronavirus (COVID-19). This study aimed to analyze the potential effect of vitamin D supplementation in reducing SARS-CoV-2 infection morbidity and severity in health care workers. Of 128 health care workers, 91 (consisting of 38 medical doctors (42%), 38 nurses (42%), and 15 medical attendants (16%)) were randomized into two groups receiving vitamin D supplementation. Participants of group I (n = 45) received water-soluble cholecalciferol at a dose of 50,000 IU/week for 2 consecutive weeks, followed by 5000 IU/day for the rest of the study. Participants of group II (n = 46) received water-soluble cholecalciferol at a dose of 2000 IU/day. For both groups, treatment lasted 3 months. Baseline serum 25(OH)D level in health care workers varied from 3.0 to 65.1 ng/mL (median, 17.7 (interquartile range, 12.2; 24.7) ng/mL). Vitamin D deficiency, insufficiency, and normal vitamin D status were diagnosed in 60%, 30%, and 10%, respectively. Only 78 subjects completed the study. Vitamin D supplementation was associated with an increase in serum 25(OH)D level, but only intake of 5000 IU/day was accompanied by normalization of serum 25(OH)D level, which occurred in 53% of cases. Neither vitamin D intake nor vitamin D deficiency/insufficiency were associated with a decrease in SARS-CoV-2 morbidity (odds ratio = 2.27; 95% confidence interval, 0.72 to 7.12). However, subjects receiving high-dose vitamin D had only asymptomatic SARS-CoV-2 in 10 (26%) cases; at the same time, participants who received 2000 IU/day showed twice as many SARS-CoV-2 cases, with mild clinical features in half of them.

A critical update on the role of mild and serious vitamin D deficiency prevalence and the COVID-19 epidemic in Europe

Objectives

Coronavirus disease 2019 (COVID-19) has emerged as a pandemic, affecting nearly 180 million people worldwide as of June 22, 2021. Previous studies have examined the association between the mean vitamin D (Vit D) concentration of each country and COVID-19 infection and mortality rate in European countries. The aim of the present study was to critically evaluate the relationship between prevalence of mild and severe Vit D deficiency in each country and COVID-19 infection, recovery, and mortality using updated data and a different methodological approach.

Methods

Information on Vit D concentration or deficiency for each country was retrieved through a literature search. COVID-19 infections and mortalities per million people and total recoveries, as of June 22, 2021, were obtained. The associations between Vit D deficiency and COVID-19 infection, recovery, and mortality were explored using correlation coefficients and scatterplots.

Results

Non-significant correlations were observed between both number of COVID-19 infections (r = 0.363, P = 0.116) and number of recoveries (r = 0.388, P = 0.091) and the prevalence of mild Vit D deficiency (<50 nmol/L). Similarly, non-significant correlations were observed between both infections (r = 0.215, P = 0.392) and recoveries (r = 0.242, P = 0.332) and the prevalence of severe Vit D deficiency (<30 nmol/L). Significant correlations were found between COVID-19 mortality and prevalence of both mild Vit D deficiency (r = 0.634, P = 0.003) and severe Vit D deficiency (r = 0.538, P = 0.021).

Conclusions

The prevalence of neither mild nor severe Vit D deficiency was associated with the number of COVID-19 infections in European countries. Thus, it is an important parameter to consider when implementing preventive measures to face COVID-19.

Low 25(OH)D Level Is Associated with Severe Course and Poor Prognosis in COVID-19

We evaluated associations between serum 25-hydroxyvitamin D [25(OH)D] level and severity of new coronavirus infection (COVID-19) in hospitalized patients. We assessed serum 25(OH)D level in 133 patients aged 21-93 years. Twenty-five (19%) patients had severe disease, 108 patients (81%) had moderate disease, and 18 (14%) patients died. 25(OH)D level ranged from 3.0 to 97.0 ng/mL (median, 13.5 [25%; 75%, 9.6; 23.3] ng/mL). Vitamin D deficiency was diagnosed in 90 patients, including 37 with severe deficiency. In patients with severe course of disease, 25(OH)D level was lower (median, 9.7 [25%; 75%, 6.0; 14.9] ng/mL), and vitamin D deficiency was more common than in patients with moderate course (median, 14.6 [25%; 75%, 10.6; 24.4] ng/mL, p = 0.003). In patients who died, 25(OH)D was 9.6 [25%; 75%, 6.0; 11.5] ng/mL, compared with 14.8 [25%; 75%, 10.1; 24.3] ng/mL in discharged patients (p = 0.001). Severe vitamin D deficiency was associated with increased risk of COVID-19 severity and fatal outcome. The threshold for 25(OH)D level associated with increased risk of severe course was 11.7 ng/mL. Approximately the same 25(OH)D level, 10.9 ng/mL, was associated with increased risk of mortality. Thus, most COVID-19 patients have vitamin D deficiency; severe vitamin D deficiency is associated with increased risk of COVID-19 severity and fatal outcome.

Impact of vitamin D deficiency on COVID-19

Background & aims

COVID-19 has emerged as a global pandemic affecting millions of people. Vitamin D deficiency is one of the risk factors for increased susceptibility to COVID-19. This study aimed to examine the correlation between the prevalence of vitamin D deficiency and COVID-19 infection and mortality rates among the adult population in European and Asian continents.

Methods

Prevalence of vitamin D deficiency in each country was retrieved through literature searching on PubMed® database for the last ten years. As of December, 31^st 2020, COVID-19 infections and mortalities per million population were extracted from the ‘real time’ statistics of the Worldometer website. The association between both vitamin D deficiency and COVID-19 infections and mortalities were explored.

Results

Forty seven countries were included in the analysis. The prevalence of vitamin D deficiency ranged from 6.9 to 81.8% in European countries and 2.0–87.5% in Asian countries. Significantly positive correlations were observed for both COVID-19 infection (r = 0.76; p < 0.001) and mortality rates (r = 0.75; p < 0.001) in the Asian continent. The correlation values for the infections and mortality rates in the European continent were (r = 0.37; p = 0.08) and (r = 0.43; p = 0.04) respectively. When both the continents were combined, the correlation results for both infection (r = 0.42; p = 0.003) and mortality (r = 0.35; p = 0.016) rates with vitamin D deficiency values remained significant.

Conclusion

Prevalence of vitamin D deficiency was significantly associated with the mortality rate of COVID-19 in Europe and Asia. The association between the infection rate and prevalence of vitamin D deficiency was significant for Asia only. Both the associations were significant when the two continents were combined in the analysis. Therefore we suggest that vitamin D supplementation could play a key role in the prevention and/or treatment of the COVID-19 patients.

Serum 25-hydroxyvitamin D concentration among users of a referral outpatient unit for vascular diseases and associated factors

OBJECTIVE

Assess serum 25-hydroxyvitamin D (25OHD) concentration and associated factors among users of a referral outpatient unit for vascular diseases in Southern Brazil.

DESIGN

Cross-sectional study conducted for almost one year, from March 2016 to January 2017. The serum vitamin D level was determined biochemically and classified as: sufficient (>50 nmol/L), insufficient (30-50 nmol/L) and deficient (<30 nmol/L). Associations were tested through multiple linear regression.

SETTING

At a reference outpatient clinic specialized in vascular diseases located in a southern Brazilian medium-sized city (latitude 29°S).

SUBJECTS

Consecutive sample of 133 individuals of both sexes, aged at least 40 years.

RESULTS

The mean serum 25OHD concentration was 54.9 ± 25.9 nmol/L (57.7 ± 27.9 nmol/L for men; 52.2 ± 24.2 nmol/L for women, p = 0.267). A total of 12.8% of the participants had vitamin D deficiency and 32.3% had insufficiency. Regarding the total sample, variables associated to the serum 25OHD concentration were: age (β = -0.55; CI95% -0.95; -0.17), sun exposure (β = 1.22; CI95% 0.32; 2.10) and vitamin D intake (β = 7.29; CI95% 2.10; 12.48). Among men, a significant association was observed for age (β = -0.82; CI95% -1.47; -0.17, p = 0.015) and borderline for sun exposure (β = 1.22; CI95% 0.32; 2.10, p = 0.053). Among women, only vitamin D intake was significantly associated with serum concentration of this vitamin (β = 8.74; CI95% 1.32; 16.17, p = 0.022).

CONCLUSION

Although the mean 25OHD concentration was greater than 50 nmol/L, about 45% of this consecutive sample presented poor vitamin D nutritional status. Unadjusted for seasonality, factors associated with serum 25OHD concentration were age and sun exposure among men and vitamin D intake among women.

Developing a Model for Prediction of Serum 25-Hydroxyvitamin D Level: The Use of Linear Regression and Machine Learning Methods

OBJECTIVE

Because vitamin D status affects many organs and tissues of the body, it is important to determine the factors affecting it. The purpose of this study was to develop a model for predicting the serum 25-hydroxyvitamin D [25(OH)D] level in healthy young adults.

METHOD

This cross-sectional study was conducted on 201 healthy individuals aged 20 to 40 years old in Shiraz, Iran. Data regarding demographic characteristics, vitamin D intake through supplements, and sun exposure habits were gathered. Serum 25(OH)D concentration was also measured. Data were analyzed with R software using linear regression and different machine learning methods such as conditional tree, conditional forest and random forest.

RESULTS

Based on the linear regression, male sex (p < 0.001), taking 50,000 IU vitamin D₃ supplement monthly (p < 0.001), and lower waist circumference (p = 0.018) were identified as effective factors in increasing serum 25(OH)D levels. According to the conditional tree, taking 50,000 IU vitamin D₃ supplement monthly (p < 0.001) and sex (p < 0.001) were two main factors in the classification of individuals in terms of serum 25(OH)D levels. Besides, conditional forest and random forest results showed that the most important variable was taking 50,000 IU vitamin D₃ supplement monthly.

CONCLUSIONS

Supplement use is the first and most important predictor of 25(OH)D levels and other factors, including sex and waist circumference, are ranked thereafter, and the importance of these factors is greater in those who do not take vitamin D₃ supplements.

Are Adequate Vitamin D Levels Helpful in Fighting COVID-19? A Look at the Evidence

COVID-19 is a global pandemic with high mortality in vulnerable groups. Given the current lack of definitive treatment or vaccine that significantly reduces mortality rate, governments, researchers and healthcare providers are racing to find possible solutions to the crisis. Vitamin D and its analogues have been previously studied for their non-skeletal benefits. In particular, questions regarding their role in the modulation of immunity have re-surfaced, in view of possible epidemiological links observed between COVID-19 and vitamin D levels in selected populations. In this review, we highlight potential mechanisms and summarise the evidence for and against the potential role of vitamin D supplementation in our fight against COVID-19.

'Scientific Strabismus' or two related pandemics: coronavirus disease and vitamin D deficiency

The WHO has announced the novel coronavirus disease (COVID-19) outbreak to be a global pandemic. The distribution of community outbreaks shows seasonal patterns along certain latitude, temperature and humidity, that is, similar to the behaviour of seasonal viral respiratory tract infections. COVID-19 displays significant spread in northern mid-latitude countries with an average temperature of 5–11°C and low humidity. Vitamin D deficiency has also been described as pandemic, especially in Europe. Regardless of age, ethnicity and latitude, recent data showed that 40 % of Europeans are vitamin D deficient (25-hydroxyvitamin D (25(OH)D) levels <50 nmol/l), and 13 % are severely deficient (25(OH)D < 30 nmol/l). A quadratic relationship was found between the prevalences of vitamin D deficiency in most commonly affected countries by COVID-19 and the latitudes. Vitamin D deficiency is more common in the subtropical and mid-latitude countries than the tropical and high-latitude countries. The most commonly affected countries with severe vitamin D deficiency are from the subtropical (Saudi Arabia 46 %; Qatar 46 %; Iran 33·4 %; Chile 26·4 %) and mid-latitude (France 27·3 %; Portugal 21·2 %; Austria 19·3 %) regions. Severe vitamin D deficiency was found to be nearly 0 % in some high-latitude countries (e.g. Norway, Finland, Sweden, Denmark and Netherlands). Accordingly, we would like to call attention to the possible association between severe vitamin D deficiency and mortality pertaining to COVID-19. Given its rare side effects and relatively wide safety, prophylactic vitamin D supplementation and/or food fortification might reasonably serve as a very convenient adjuvant therapy for these two worldwide public health problems alike.

High-Dose Vitamin D Supplementation Improves Microcirculation and Reduces Inflammation in Diabetic Neuropathy Patients

We assessed the effect of different doses of vitamin D supplementation on microcirculation, signs and symptoms of peripheral neuropathy and inflammatory markers in patients with type 2 diabetes (T2DM). Sixty-seven patients with T2DM and peripheral neuropathy (34 females) were randomized into two treatment groups: Cholecalciferol 5000 IU and 40,000 IU once/week orally for 24 weeks. Severity of neuropathy (NSS, NDS scores, visual analogue scale), cutaneous microcirculation (MC) parameters and inflammatory markers (ILs, CRP, TNFα) were assessed before and after treatment. Vitamin D deficiency/insufficiency was detected in 78% of the 62 completed subjects. Following treatment with cholecalciferol 40,000 IU/week, a significant decrease in neuropathy severity (NSS, p = 0.001; NDS, p = 0.001; VAS, p = 0.001) and improvement of cutaneous MC were observed (p < 0.05). Also, we found a decrease in IL-6 level (2.5 pg/mL vs. 0.6 pg/mL, p < 0.001) and an increase in IL-10 level (2.5 pg/mL vs. 4.5 pg/mL, p < 0.001) after 24 weeks of vitamin D supplementation in this group. No changes were detected in the cholecalciferol 5000 IU/week group. High-dose cholecalciferol supplementation of 40,000 IU/week for 24 weeks was associated with improvement in clinical manifestation, cutaneous microcirculation and inflammatory markers in patients with T2DM and peripheral neuropathy.

serum 25(oH)D level in patients with CoVID-19

Recently, vitamin D deficiency is considered as a risk factor for the incidence and severity of new coronavirus infection.The aimof this work was to evaluate the vitamin D level of patients with COVID-19 hospitalized with communityacquired pneumonia and compare the value of 25(OH)D in blood serum with the clinical manifestations of the disease.Results.Included are 80 patients aged 18 to 94 years (mean age 53,2 ± 15,7 years), 43 (53,8%) men; with severe course – in 25 (31,3%) patients (12 males), and moderate – in 55 people (68,7%) (31 males). Half of the severely ill patients were obese, and among the deceased patients, the number of obese people was 61,5%, which was significantly higher than the discharged ones – 14,9% (p<0,001). Diabetes mellitus and cardiovascular diseases occurred with the same frequency, regardless of the severity of the disease. Analysis of the outcomes of coronavirus infection in these patients showed mortality in 52,0% of cases in severe patients. Serum 25(OH)D level ranged from 3,0 to 88,8 ng / ml (16,7 ± 12,7 ng / ml). It was found that in patients with severe course, the level of 25(OH)D blood was significantly lower (11.9 ± 6.4 ng / ml) and vitamin D deficiency was more common than in patients with moderate to severe course of the disease (18,5 ± 14,0 ng / ml, p = 0,027). The same pattern was revealed in patients with a fatal outcome, where the level of 25(OH)D was 10,8 ± 6,1 ng / ml, compared with this indicator in patients discharged from the hospital (17,8 ± 13,4 ng / ml) (p = 0,02).Conclusions.Vitamin D deficiency and obesity have been found to increase the risk of severe course and death of coronavirus infection.

The effect of vitamin D therapy on inflammatory markers in patients with type 2 diabetes mellitus and diabetic peripheral polyneuropathy

BACKGROUND: The pathogenesis of diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM) is multifactorial, and includes increased inflammation. In recent years, the effect of vitamin D therapy on improving the profile of inflammatory parameters has been actively studied. AIMS: The aim of this study was to assess inflammation markers before and after various doses of cholecalciferol therapy in T2DM with DPN. MATERIALS AND METHODS: Single-center open randomized study included T2DM patients with PDN. Sixty-seven patients were randomized into 2 groups. For 24 weeks Group I have been taking a dosage of cholecalciferol 5,000 IU/week, and Group II a dosage of 40,000 IU/week. At the baseline and in the end of the research there have been studied body mass index (BMI), glycated hemoglobin (HbA1c), 25-hydroxyvitamin D (25(OH)D), PTH, interleukin-1, -6, -10 (IL), C-reactive protein (CRP), tumor necrosis factor - (TNF). RESULTS: Sixty-two patients completed the study. Group I (n=31, F16), Group II (n=31, F15) were initially compared by age, sex, BMI and НbA1clevel. Vitamin D deficiency/insufficiency was detected in 78% of patients with T2DM. After 24 weeks of therapy with cholecalciferol in Group II there was a significant decrease in BMI, HbA1c, IL-6 levels and an increase in IL-10 levels while no changes were found in Group I. There has been established a correlation between the final level of 25(OH)D and IL-6 (r=-0.378, p=0.036), IL-10 (r=0.483, p=0.006), BMI (r=-0.388, p=0.031) and НbA1c(r=-0.388, p=0.031). CONCLUSION: The intake of cholecalciferol at a dosage of 40,000 IU/week for 24 weeks is associated with a decrease in BMI, improvement of glycemic control and pro-inflammatory markers profile in patients with T2DM with DPN. Study results showed that the normalization of serum 25(OH)D level can be one of the modifying factors for the development and progression of DPN in patients with T2DM.

Comparison of seasonal serum 25-hydroxyvitamin D concentrations among pregnant women in Mongolia and Boston

Adequate vitamin D status during pregnancy is important for developing fetal bone strength and density and may play a role in preventing a range of skeletal and non-skeletal diseases in both mothers and children. We previously identified Mongolian women of reproductive age to have the lowest vitamin D levels yet observed in any population globally, which renders this population uniquely important in vitamin D research. In this study, we measured the seasonal distribution of 25-hydroxyvitamin D (25(OH)D) concentration in 390 healthy third trimester pregnant women living in urban and rural Mongolia using DiaSorin LIAISON and compared this distribution to that of 206 third trimester women living in Boston, USA. Also, we analyzed seasonally-independent associations between (25(OH)D) levels and selected predictors in both groups using quantile regression. Mean 25(OH)D levels were significantly higher and less seasonal in Boston (seasonal range: 27.1 ± 7.0-31.5 ± 7.7 ng/ml) than in Mongolia (seasonal range: 11.2 ± 3.9-19.2 ± 6.7 ng/ml). Adjusting for month of blood draw, higher 25(OH)D levels were significantly associated with older age, lower gravidity, lower BMI, and lack of a college or university degree among Boston participants, however, only gravidity was robust to multivariable adjustment. No assessed characteristics were independently predictive in Mongolia, likely due to universally low 25(OH)D levels and a resulting lack of between-person variation. In conclusion, vitamin D status among pregnant Mongolians is severely depressed throughout the year and should be addressed through fortification and supplementation, while in the U.S., deficiency is associated with specific characteristics targetable through supplementation.

Vitamin D deficiency and its associated risk factors in normal adult population of Birjand, Iran

BACKGROUND

Vitamin D is required for calcium absorption, bone growth, and regulation of the immune system. Geographical location determines the intensity of the solar ultraviolet (UV) light as a significant determinant of vitamin D status in the many studies. This study was conducted to determine the status of vitamin D deficiency and its associated factors in adults of Birjand city, Iran (latitude: 32.87; longitude: 59.22).

METHODS

This descriptive-analytic study was performed by random stratified sampling on 400 subjects over 40 years of age in Birjand, who signed the consent form for participation. Data were collected in winter within one month from eight municipal health centers. Information regarding demographic characteristics, blood pressure, and anthropometric indices were collected, and blood samples were collected to measure 25-hydroxyvitamin D concentration.

RESULTS

The mean serum concentration of 25-OHD was 45.4 nmol/L. Twenty-six percent of subjects had vitamin D deficiency, 45.2% had insufficiency, and 28.8% of the subjects were healthy. The results of the multiple logistic regression showed that age (OR: 0.92, 95% CI = 0.89-0.96) and serum calcium concentration (OR: 0.52, 95% CI = 0.28-0.94) had a significant correlation with 25-OHD deficiency.

CONCLUSION

A high percentage of adults in the city of Birjand are suffering from vitamin D deficiency, which implies a need for extensive training and food enrichment programs, promoting healthy lifestyles, and exercise and walking.

Role of vitamin D deficiency in type 2 diabetes mellitus and diabetic neuropathy development

Type 2 diabetes mellitus (DM) is a global epidemic associated with severe vascular complications development. Diabetic neuropathy is the most common chronic complication of DM that worsens patients life quality and prognosis. Therefore, studies dealing with DM and diabetic neuropathy underlying mechanisms are extremely relevant. The review discusses current views on vitamin D role in glucose metabolism and inflammatory processes. It is reported that vitamin D deficiency can contribute to insulin resistance development, and change in vitamin D receptor activity or extra- and intracellular calcium concentration due to vitamin D deficiency can affect pancreatic -cells function and lead to decrease in insulin production. Key pathogenic mechanisms of diabetic neuropathy as well as possible relationship between vitamin D deficiency and neuropathy development are in focus of this review. Results of recent clinical trials regarding vitamin D supplementation in patients with DM are also discussed. The presented data suggest that vitamin D deficiency can be considered as a non-classical risk factor for the development of not only DM but its complications as well.

Relationship Between Vitamin D Status and Vitamin D Receptor Gene Polymorphisms With Markers of Metabolic Syndrome Among Adults

Introduction: Recent studies have demonstrated that vitamin D deficiency contributes to the development of metabolic disorders, including obesity and type 2 diabetes mellitus (T2DM). Several vitamin D receptor (VDR) gene polymorphisms had been described to play a role in these conditions since vitamin D receptors were found in many tissues. The aim of this study was to assess the relationship between vitamin D status and VDR gene polymorphisms with metabolic syndrome (MS) parameters in Russian middle-aged women. Materials and Methods: A total of 697 women aged between 30 to 55 years were included in this cross-sectional study. Serum 25-hydroxyvitamin D (25(OH)D) level and four VDR gene polymorphisms rs1544410 (BsmI), rs7975232 (ApaI), rs731236 (TaqI), and rs2228570 (FokI) were measured. We applied the International Diabetes Federation (IDF) criteria to identify subjects with MS. Results: 9.3% of subjects had normal vitamin D level, while 90.7% were insufficient or deficient. Abdominal obesity (AO) was seen in 75.5%, impaired glucose tolerance (IGT) or T2DM was observed in 33.3%, reduced high-density lipoprotein cholesterol (HDL-C) level in 32.2% and hypertriglyceridemia in 23.4%. Serum 25(OH)D level in women with or without MS did not differ (48.6 ± 1.8 and 51.1 ± 1.5 nmol/l, p > 0.05). Subjects with vitamin D deficiency showed an increased risk of AO [CI 95% 2.23; 1.15-4.30] and low HDL-C [CI95% 2.60; 1.04-6.49] compared to subjects with normal 25(OH)D level. IGT and T2DM risk was increased only when 25(OH)D concentration was less than 39.0 nmol/l [CI 95% 7.17; 2.99-17.7], but risk of MS did not differ in normal vitamin D status subjects and insufficient/deficient ones (p > 0.05). T allele carriers (A) of rs7975232 had higher total cholesterol and low-density lipoprotein cholesterol levels compared with the GG (aa) genotypes. Similarly, GG (BB) genotype carriers of rs1544410 had higher triglyceride levels than subjects with A (b) allele carriers. However VDR gene polymorphisms did not seem to be associated with an increased risk of MS. Conclusions: Vitamin D deficiency, rs7975232, and rs1544410 VDR gene variants are associated with MS parameters in Russian middle-aged women.

Evidence of a significant vitamin D deficiency among 9-13-year-old Polish children: results of a multicentre study

PURPOSE

To evaluate the extent to which the population of Polish preadolescents is vitamin D deficient and to assess seasonal variations in vitamin D status.

PARTICIPANTS AND METHODS

A total of 720 healthy children aged 9-13 years (409 girls, 311 boys) residing in 6 representative geographical locations in Poland were studied. A parental-assisted questionnaire provided data on nutritional habits, vitamin D supplements and sun exposure. Serum concentration of 25-hydroxyvitamin was determined twice, after the winter in March and after the summer in October.

RESULTS

In March, vitamin D deficiency (25-50 nmol/L) was found in 64%, and severe deficiency (< 25 nmol/L) in 20.2% of children. In October, the deficiency and severe deficiency were still noticed in 25.9 and 0.1% of children, respectively. The mean serum concentration of 25-OHD was 52% higher in October (55.4 ± 14.0 nmol/L) than in March (36.4 ± 13.5 nmol/L), (p < 0.01). In children with 25-OHD < 50 nmol/L in March, their 25-OHD concentration increased by 64% through March to October (32.5 ± 8.2 vs. 53.2 ± 7.9 nmol/L, p < 0.01). An association was found between 25-OHD concentration and regular consumption of vitamin D supplements, cod-liver oil and fish.

CONCLUSIONS

The majority of preadolescent Polish boys and girls show vitamin D deficiency after the winter period, although a distinct amelioration over summertime is found in this age group. There is a need to implement effective prevention and intervention strategies in the management of vitamin D deficiency among schoolchildren in Poland, with the supplementation throughout the entire year.

Serum 25-hydroxyvitamin D levels in hospitalized adults with community-acquired pneumonia

INTRODUCTION

Community-acquired pneumonia (CAP) is the infectious disease with the highest number of deaths worldwide. Several studies have shown an association between vitamin D deficiency and increases susceptibility to respiratory tract infections.

OBJECTIVE

The aim of this study was to evaluate the serum 25-hydroxyvitamin D (25OHD) levels in hospitalized adults in general room with CAP.

MATERIALS AND METHODS

An observational study was carried out in 207 hospitalized adults of both sex with CAP (>18 years) from Rosario city, Argentina (32° 52' 18″S) between July 2015 and June 2016.

RESULTS

In total, 167 patients were included in the data analysis [59% women (57.4 ± 19.6 years), body mass index 27.2 ± 7.8 kg/m² ]. In brief, 63% showed unilobar infiltrate and 37% were multilobar. The CURB-65 index was 66.5% low risk, 16.0% intermediate risk and 17.5% high risk. According to Charlson comorbidity index (CCI) 53.5% had not comorbidity (CCI = 0) and 46.5% showed CCI ≥ 1. The 25OHD level was: 11.92 ± 7.6 ng/mL (51.5%: <10 ng/mL, 33.5%: 10-20 ng/mL, 13.2%: 20-30 ng/mL and 1.8%: >30 ng/mL). Higher 25OHD were found in male (female: 10.8 ± 6.7 ng/mL, male: 13.5 ± 8.5 ng/mL, P = .02) and 25OHD correlated with age (r = -.17; P = .02). 25-Hydroxyvitamin D was also correlated with CURB65 index (r = -.13; P = .049), CCI (r = -.20, P = .007) and with the 10 years of life expectative (%) (r = .19; P = .008). In addition, higher 25OHD were found with lower CCI (CCI 0 = 13.0 ± 8.2 ng/mL, CCI ≥ 1= 10.5 ± 6.7 ng/mL; P = .0093).

CONCLUSIONS

Hospitalized adults with CAP have lower 25OHD levels and would be associated with the severity of CAP.

OSTEOPOROSIS IN RUSSIAN FEDERATION: EPIDEMIOLOGY, SOCIO-MEDICAL AND ECONOMICAL ASPECTS (REVIEW)

The authors performed an analysis of published stadies devoted to osteoporosis situation in Russian Federation including epidemiological, social, medical and economical aspects of this pathology. The analysis demonstrated that osteoporosis is reported in every third woman and every forth man of 50 years old and older. Seven vertebra fractures happen every minute and one fracture of proximal femur — every 5 minutes in Russia. An overall number of all key osteoporotic fractures will increase from 590 thousand up to 730 thousand cases by the year 2035. Osteoporosis is financially demanding for healthcare due to high treatment cost of fractures that are accompanied by life quality deterioration, high mortality and invalidization of patients. Epidemiological studies demonstrated that due to high fracture risk the osteoporosis therapy should be assigned to 31% of female and 4% of male patients over 50 years old. Such factors of osteoporosis risks are widespread in the society: smoking, low food calcium consumption, vitamin D deficit, low physical activity. The authors analyzed the problems in organization of medical care to patients with osteoporosis and osteoporotic fractures and possible solutions to existing issues. The organization of healthcare should be addressed at identification of high risk patient groups, early diagnosis and assignment of corresponding treatment aimed at decreasing potential fracture risk as well as at pathology prophylaxis.