Vitamin D status and health correlates among German adults

Unveiling the Interplay-Vitamin D and ACE-2 Molecular Interactions in Mitigating Complications and Deaths from SARS-CoV-2

The interaction of the SARS-CoV-2 spike protein with membrane-bound angiotensin-converting enzyme-2 (ACE-2) receptors in epithelial cells facilitates viral entry into human cells. Despite this, ACE-2 exerts significant protective effects against coronaviruses by neutralizing viruses in circulation and mitigating inflammation. While SARS-CoV-2 reduces ACE-2 expression, vitamin D increases it, counteracting the virus's harmful effects. Vitamin D's beneficial actions are mediated through complex molecular mechanisms involving innate and adaptive immune systems. Meanwhile, vitamin D status [25(OH)D concentration] is inversely correlated with severity, complications, and mortality rates from COVID-19. This study explores mechanisms through which vitamin D inhibits SARS-CoV-2 replication, including the suppression of transcription enzymes, reduced inflammation and oxidative stress, and increased expression of neutralizing antibodies and antimicrobial peptides. Both hypovitaminosis D and SARS-CoV-2 elevate renin levels, the rate-limiting step in the renin-angiotensin-aldosterone system (RAS); it increases ACE-1 but reduces ACE-2 expression. This imbalance leads to elevated levels of the pro-inflammatory, pro-coagulatory, and vasoconstricting peptide angiotensin-II (Ang-II), leading to widespread inflammation. It also causes increased membrane permeability, allowing fluid and viruses to infiltrate soft tissues, lungs, and the vascular system. In contrast, sufficient vitamin D levels suppress renin expression, reducing RAS activity, lowering ACE-1, and increasing ACE-2 levels. ACE-2 cleaves Ang-II to generate Ang(1-7), a vasodilatory, anti-inflammatory, and anti-thrombotic peptide that mitigates oxidative stress and counteracts the harmful effects of SARS-CoV-2. Excess ACE-2 molecules spill into the bloodstream as soluble receptors, neutralizing and facilitating the destruction of the virus. These combined mechanisms reduce viral replication, load, and spread. Hence, vitamin D facilitates rapid recovery and minimizes transmission to others. Overall, vitamin D enhances the immune response and counteracts the pathological effects of SARS-CoV-2. Additionally, data suggests that widely used anti-hypertensive agents-angiotensin receptor blockers and ACE inhibitors-may lessen the adverse impacts of SARS-CoV-2, although they are less potent than vitamin D.

Analysis of Cellular Stress Assay Parameters and Intracellular ATP in Platelets: Comparison of Platelet Preparation Methods

Platelets are metabolically active, anucleated and small circulating cells mainly responsible for the prevention of bleeding and maintenance of hemostasis. Previous studies showed that platelets mitochondrial content, function, and energy supply change during several diseases such as HIV/AIDS, COVID-19, pulmonary arterial hypertension, and in preeclampsia during pregnancy. These changes in platelets contributed to the severity of diseases and mortality. In our previous studies, we have shown that the seahorse-based cellular stress assay (CSA) parameters are crucial to the understanding of the mitochondrial performance in peripheral blood mononuclear cells (PBMCS). Moreover, the results of CSA parameters were significantly influenced by the PBMC preparation methods. In this study, we assessed the correlation of CSA parameters and intracellular ATP content in platelets and evaluated the effects of platelet preparation methods on the results of CSA parameters and intracellular ATP content. We compared the results of CSA parameters and intracellular ATP content in platelets isolated by density centrifugation with Optiprep and simple centrifugation of blood samples without Optiprep. Platelets isolated by centrifugation with Optiprep showed a higher spare capacity, basal respiration, and maximal respiration than those isolated without Optiprep. There was a clear correlation between basal respiration and maximal respiration, and the whole-ATP content in both isolation methods. Moreover, a positive correlation was observed between the relative spare capacity and whole-cell ATP content. In conclusion, the results of seahorse-based CSA parameters and intracellular ATP content in platelets are markedly influenced by the platelet isolation methods employed. The results of basal respiration and maximal respiration are hallmarks of cellular activity in platelets, and whole-cell ATP content is a potential hint for basic platelet viability. We recommend further studies to evaluate the role of CSA parameters and intracellular ATP content in platelets as biomarkers for the diagnosis and prediction of disease states.

Vitamin D Deficiency Is Frequent in Patients with Rapidly Destructive Osteoarthritis-Data from a Single-Center Analysis

BACKGROUND

Rapidly destructive osteoarthritis (RDO) of the hip joint is characterised by the rapid destruction of the femoral head with or without acetabular involvement. There has been increasing interest in this disease over the past years; however, the entity is still poorly understood, and its pathophysiology remains unknown. Yet, there is ample evidence today that increased bone metabolism might play a role in the onset and progression of the disease. Vitamin D is of utmost importance to maintain a balanced bone metabolism. However, whether vitamin D deficiency is involved in disease development remains to be elucidated. Further, the vitamin D status of patients with RDO has not yet been analysed. For this reason, the objective of this study was to assess the vitamin D status of patients with RDO. Moreover, the aim was to clarify whether there is a difference in the vitamin D status of patients with RDO compared with patients with primary osteoarthritis (OA).

METHODS

In this single-centre analysis, the 25(OH)D, PTH, and calcium levels of 29 patients who presented with RDO between 2020 and 2022 were assessed.

RESULTS

Altogether, 97% of patients (28/29) were vitamin D deficient, a further 3% (1/29) were vitamin D insufficient, and not a single patient presented with a sufficient vitamin D status. Notably, the vitamin D levels of RDO patients (mean = 11.04 ng/mL) were significantly lower than the vitamin D levels of patients with OA (mean = 22.16 ng/mL, p = 0.001).

CONCLUSION

In conclusion, we found a widespread and high rate of vitamin D deficiency in patients with RDO. Hence, we believe that 25(OH)D status should routinely be analysed in these patients.

Therapeutic Consequences of Targeting the IGF-1/PI3K/AKT/FOXO3 Axis in Sarcopenia: A Narrative Review

The high prevalence of sarcopenia in an aging population has an underestimated impact on quality of life by increasing the risk of falls and subsequent hospitalization. Unfortunately, the application of the major established key therapeutic-physical activity-is challenging in the immobile and injured sarcopenic patient. Consequently, novel therapeutic directions are needed. The transcription factor Forkhead-Box-Protein O3 (FOXO3) may be an option, as it and its targets have been observed to be more highly expressed in sarcopenic muscle. In such catabolic situations, Foxo3 induces the expression of two muscle specific ubiquitin ligases (Atrogin-1 and Murf-1) via the PI3K/AKT pathway. In this review, we particularly evaluate the potential of Foxo3-targeted gene therapy. Foxo3 knockdown has been shown to lead to increased muscle cross sectional area, through both the AKT-dependent and -independent pathways and the reduced impact on the two major downstream targets Atrogin-1 and Murf-1. Moreover, a Foxo3 reduction suppresses apoptosis, activates satellite cells, and initiates their differentiation into muscle cells. While this indicates a critical role in muscle regeneration, this mechanism might exhaust the stem cell pool, limiting its clinical applicability. As systemic Foxo3 knockdown has also been associated with risks of inflammation and cancer progression, a muscle-specific approach would be necessary. In this review, we summarize the current knowledge on Foxo3 and conceptualize a specific and targeted therapy that may circumvent the drawbacks of systemic Foxo3 knockdown. This approach presumably would limit the side effects and enable an activity-independent positive impact on skeletal muscle.

The Determination of Mitochondrial Mass Is a Prerequisite for Accurate Assessment of Peripheral Blood Mononuclear Cells' Oxidative Metabolism

Mitochondria are responsible for ATP synthesis through oxidative phosphorylation in cells. However, there are limited data on the influence of mitochondrial mass (MM) in the adequate assessment of cellular stress assay (CSA) results in human peripheral blood mononuclear cells (PBMCs). Therefore, the aim of this study was to determine MM in PBMCS and assess its influence on the results of CSA measurements. Blood samples were collected and sent to the laboratory for MM and CSA measurements during different seasons of the year. The mitochondrial mass was determined based on the mtDNA:nDNA ratio in PBMCs using quantitative real-time PCR (qRT-PCR). CSA was measured using Seahorse technology. The MM was significantly lower during summer and autumn compared to winter and spring (p < 0.0001). On the contrary, we found that the maximal respiration per mitochondrion (MP) was significantly higher in summer and autumn compared to winter and spring (p < 0.0001). The estimated effect of MM on mitochondrial performance was -0.002 pmol/min/mitochondrion (p < 0.0001) and a correlation coefficient (r) of -0.612. Similarly, MM was negatively correlated with maximal respiration (r = -0.12) and spare capacity (in % r = -0.05, in pmol/min r = -0.11). In conclusion, this study reveals that MM changes significantly with seasons and is negatively correlated with CSA parameters and MP. Our findings indicate that the mitochondrial mass is a key parameter for determination of mitochondrial fitness. Therefore, we recommend the determination of MM during the measurement of CSA parameters for the correct interpretation and assessment of mitochondrial function.

25-hydroxyvitamin D level is associated with greater grip strength across adult life span: a population-based cohort study

OBJECTIVE

Maintaining muscle function throughout life is critical for healthy ageing. Although in vitro studies consistently indicate beneficial effects of 25-hydroxyvitamin D (25-OHD) on muscle function, findings from population-based studies remain inconclusive. We therefore aimed to examine the association between 25-OHD concentration and handgrip strength across a wide age range and assess potential modifying effects of age, sex and season.

METHODS

We analysed cross-sectional baseline data of 2576 eligible participants out of the first 3000 participants (recruited from March 2016 to March 2019) of the Rhineland Study, a community-based cohort study in Bonn, Germany. Multivariate linear regression models were used to assess the relation between 25-OHD levels and grip strength while adjusting for age, sex, education, smoking, season, body mass index, physical activity levels, osteoporosis and vitamin D supplementation.

RESULTS

Compared to participants with deficient 25-OHD levels (<30 nmol/L), grip strength was higher in those with inadequate (30 to <50 nmol/L) and adequate (≥50 to ≤125 nmol/L) levels (ßinadequate = 1.222, 95% CI: 0.377; 2.067, P = 0.005; ßadequate = 1.228, 95% CI: 0.437; 2.019, P = 0.002). Modelling on a continuous scale revealed grip strength to increase with higher 25-OHD levels up to ~100 nmol/L, after which the direction reversed (ßlinear = 0.505, 95% CI: 0.179; 0.830, P = 0.002; ßquadratic = -0.153, 95% CI: -0.269; -0.038, P = 0.009). Older adults showed weaker effects of 25-OHD levels on grip strength than younger adults (ß25OHDxAge = -0.309, 95% CI: -0.594; -0.024, P = 0.033).

CONCLUSIONS

Our findings highlight the importance of sufficient 25-OHD levels for optimal muscle function across the adult life span. However, vitamin D supplementation should be closely monitored to avoid detrimental effects.

Prevalence and Relevance of Vitamin D Deficiency in Newly Diagnosed Breast Cancer Patients: A Pilot Study

(1) Background: Vitamin D plays an important role in many types of cancer. It was the aim of this study to analyze serum 25-hydroxyvitamin D (25(OH)D) levels in newly diagnosed breast cancer patients, and the association with prognostic and lifestyle factors. (2) Methods: 110 non-metastatic breast cancer patients were included in the prospective observational “BEGYN” study at Saarland University Medical Center between September 2019 and January 2021. At the initiation visit, serum 25(OH)D levels were measured. Clinicopathological data on prognosis, nutrition, and lifestyle were extracted from data files and obtained using a questionnaire. (3) Results: Median serum 25(OH)D in breast cancer patients was 24 ng/mL (range 5–65 ng/mL), with 64.8% of patients being vitamin D deficient. 25(OH)D was higher among patients that reported the use of vitamin D supplements (43 ng/mL versus 22 ng/mL; p < 0.001), and in summer compared to other seasons (p = 0.03). Patients with moderate vitamin D deficiency were less likely to have triple negative breast cancer (p = 0.047). (4) Conclusions: Routinely measured vitamin D deficiency is common in breast cancer patients and needs to be detected and treated. However, our results do not support the hypothesis that vitamin D deficiency may be a main prognostic factor for breast cancer.

Association between vitamin D and cardiovascular health: Myth or Fact? A narrative review of the evidence

Vitamin D deficiency is prevalent worldwide. Since the discovery of the expression of vitamin D receptor in ventricular cardiomyocytes, fibroblasts, and blood vessels, there has been a growing body of literature assessing the link between vitamin D status and cardiovascular health from one side, and the effect of vitamin D supplementation on prevention of cardiovascular diseases from the other side. In this review, we summarized studies highlighting the role of vitamin D on cardiovascular health, namely atherosclerosis, hypertension, heart failure, and metabolic syndrome, a recognized significant risk factor for cardiovascular diseases. Studies showed discrepancies between findings from cross-sectional and longitudinal cohorts and those from interventional trials, but also between one outcome and another. Cross-sectional studies found a strong association between low 25 hydroxyvitamin D (25(OH)D3) and acute coronary syndrome, and heart failure. These findings encouraged the promotion for vitamin D supplementation as a preventive measure for cardiovascular diseases in the elderly, namely in women. This fact, however, turned out into a myth with the results of large interventional trials that did not show any benefit from vitamin D supplementation in reducing ischemic events, heart failure or its outcomes, or hypertension. Although some clinical studies showed beneficial effect of vitamin D supplementation on insulin sensitivity and metabolic syndrome, this effect was not consistent across all studies.

Calcium status assessment at the population level: Candidate approaches and challenges

Inadequate dietary calcium intake is a global public health problem that disproportionately affects low- and middle-income countries. However, the calcium status of a population is challenging to measure, and there are no standard methods to identify high-risk communities even in settings with an elevated prevalence of a disease caused or exacerbated by low calcium intake (e.g., rickets). The calcium status of a population depends on numerous factors, including intake of calcium-rich foods; the bioavailability of the types of calcium consumed in foods and supplements; and population characteristics, including age, sex, vitamin D status, and genetic attributes that influence calcium retention and absorption. The aim of this narrative review was to assess candidate indicators of population-level calcium status based on a range of biomarkers and measurement methods, including dietary assessment, calcium balance studies, hormonal factors related to calcium, and health outcomes associated with low calcium status. Several promising approaches were identified, but there was insufficient evidence of the suitability of any single indicator to assess population calcium status. Further research is required to develop and validate specific indicators of calcium status that could be derived from the analysis of data or samples that are feasibly collected in population-based surveys.

Vitamin D status of the Russian adult population from 2013 to 2018

Vitamin D deficiency is widespread globally, however available data for the Russian adult population is fragmented. This cross-sectional study used secondary data for individuals undergoing testing for vitamin D concentrations from 2013 to 2018 by InVitro laboratory. 25(OH)D serum concentration was determined using chemiluminescent microparticle immunoassay. The mean, median, and proportion with severe, deficient, insufficient and sufficient 25-hydroxyvitamin D (25(OH)D) concentrations were estimated. Splines examined the effect of latitude on 25(OH)D concentrations. Data were available for 30,040 subjects age ≥ 18 years. 24.2% of the sampled population had sufficient (30-< 150 25(OH)D ng/mL), 34% deficient (10-19.9 ng/mL) and 5.6% severely deficient (< 10 ng/mL) status. Average 25(OH)D concentrations were highest among 30-44 years and lowest amongst older adults; females had modestly higher values. Concentrations were 15% higher in fall/summer vs. winter/spring. A non-linear relationship was observed by latitude; the highest 25(OH)D concentrations were observed near 54°N, decreasing at more southern latitudes for women and more northern latitudes for both sexes. These results are comparable to other Northern European publications and limited Russian samples demonstrating low concentrations. Acknowledging that nationally-representative and randomly sampled data are needed, the present data suggest the burden may be high and identifies some population sub-groups and geographic areas with a higher potential deficiency of vitamin D.

UVB-exposed wheat germ oil increases serum 25-hydroxyvitamin D2 without improving overall vitamin D status: a randomized controlled trial

PURPOSE

This study investigated whether UVB-exposed wheat germ oil (WGO) is capable to improving the vitamin D status in healthy volunteers.

METHODS

A randomized controlled human-intervention trial in parallel design was conducted in Jena (Germany) between February and April. Ultimately, 46 healthy males and females with low mean 25-hydroxyvitamin D (25(OH)D) levels (34.9 ± 10.6 nmol/L) were randomized into three groups receiving either no WGO oil (control, n = 14), 10 g non-exposed WGO per day (- UVB WGO, n = 16) or 10 g WGO, which was exposed for 10 min to ultraviolet B-light (UVB, intensity 500-630 µW/cm2) and provided 23.7 µg vitamin D (22.9 µg vitamin D2 and 0.89 µg vitamin D3) (+ UVB WGO, n = 16) for 6 weeks. Blood was obtained at baseline, after 3 and 6 weeks and analyzed for serum vitamin D-metabolite concentrations via LC-MS/MS.

RESULTS

Participants who received the UVB-exposed WGO were characterized by an increase of circulating 25(OH)D2 after 3 and 6 weeks of intervention. However, the 25(OH)D3 concentrations decreased in the + UVB WGO group, while they increased in the control groups. Finally, the total 25(OH)D concentration (25(OH)D2 + 25(OH)D3) in the + UVB WGO group was lower than that of the non-WGO receiving control group after 6 weeks of treatment. In contrast, circulating vitamin D (vitamin D2 + vitamin D3) was higher in the + UVB WGO group than in the control group receiving no WGO.

CONCLUSION

UVB-exposed WGO containing 23.7 µg vitamin D can increase 25(OH)D2 levels but do no improve total serum levels of 25(OH)D of vitamin D-insufficient subjects.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03499327 (registered, April 13, 2018).

Adherence to Lifestyle Recommendations for Bone Health in Older Adults with and without Osteoporosis: Cross-Sectional Results of the OUTDOOR ACTIVE Study

Sustaining good bone health into older age is key for preventing osteoporosis. Bone health is associated with several lifestyle factors. This study investigates older adults' adherence to bone health-promoting lifestyle recommendations dependent on osteoporosis status. Cross-sectional data of 1610 community-dwelling older adults (65-75 years) residing in Bremen, Germany (53.4% female) were included. The Osteoporosis Self-Assessment Tool and self-reported osteoporosis diagnosis were used to classify participants by osteoporosis status (low risk, high risk, diagnosis). Adherence to bone health recommendations regarding calcium and vitamin D intake, sun exposure, alcohol consumption, resistance/weight-bearing exercise, and physical activity were assessed. Descriptive statistics were applied, stratified by sex and osteoporosis status. A total of 91 women (10.6%) and 15 men (2.0%) reported an osteoporosis diagnosis, 457 women (43.2%) and 311 men (41.4%) were classified as having a high risk, and 311 women (36.2%) and 425 men (56.6%) as having a low risk. Adherence to bone health recommendations was high for calcium intake (93.3-100.0%), vitamin D intake (77.8-93.3%), and sun exposure (86.7-97.7%). Lower adherence was observed regarding resistance/weight-bearing exercise (36.3-54.4%), physical activity (14.3-57.7%), and alcohol consumption (40.0-72.4%). In conclusion, tailored prevention strategies are needed that focus on older adults with an osteoporosis diagnosis or who are at high risk.

Plasma Levels of Bioactive Vitamin D and A5 Ligands Positively Correlate with Clinical Atopic Dermatitis Markers

BACKGROUND

Over the past decade, several controversial studies described a relationship between vitamin D and atopic diseases. Low plasma vitamin D levels or even vitamin D deficiency was associated with an increased incidence of atopic disease, postulating that a higher dietary intake of vitamin D may be a beneficial strategy against atopic diseases such as atopic dermatitis (AD).

OBJECTIVE

Our aim was to determine the relationship between plasma 25-hydroxyvitamin D3 (25(OH)D3) levels, the levels of the ligand of the vitamin D receptor (VDR) heterodimerization partner as well as the retinoid X receptor (RXR) and the active vitamin A5 derivative 9-cis-13,14-dihydroretinoic acid (9CDHRA) and AD severity.

METHODS/RESULTS

Samples from AD patients (n = 20) and healthy volunteers (n = 20) were assessed. In our study, the frequently measured VDR ligand precursor 25(OH)D3 in addition to the VDR-ligand 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and 9CDHRA displayed no different levels when compared with the plasma of AD patients and healthy volunteers. When performing further correlation studies focusing on AD patients, plasma 25(OH)D3 levels showed a negative correlation with eosinophils in blood (EOS) and SCORing Atopic Dermatitis (SCORAD) values, while 1,25(OH)2D3 and 9CDHRA levels correlated positively with plasma IgE, EOS, and SCORAD values.

CONCLUSION

In consequence, the metabolic activation of vitamin D from 25(OH)D3 towards 1,25(OH)2D3 as well as the co-liganding of the RXR by 9CDHRA may be an important signalling mechanism, an important marker for AD development and severity as well as the basis for novel nutritional and pharmaceutical AD treatment options.

Prevalence of low vitamin D levels in patients with Hidradenitis suppurativa in Jordan: A comparative cross-sectional study

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the apocrine gland bearing skin, presenting various stages of flexural skin pain, erythema, painful nodules, abscesses, sinuses, and fistulas. We aimed to assess serum vitamin D levels in patients with (HS) in Jordan. a cross-sectional comparative study conducted among 110 patients with HS and 110 matched controls, who didn't previously receive vitamin D therapy. Serum vitamin D was measured and classified into normal (>30 ng/ml), insufficient (20-30 ng/ml), and low (<20 ng/ml). The mean age of the cases was 43.1 ± 12.9 years and the mean disease duration was 19.4 months. The mean body mass index among patients with HS was 30 and about 34% of them were smokers. The mean Vitamin D level was 8.4 ng/ml and all HS patients were vitamin D deficient. Patients of HS were more likely to have vitamin D deficiency compared to healthy controls. Most of the study subjects and particularly all of the patients with HS have low vitamin D levels. Smoking and high BMI, were associated with HS. We suggest the implementation standard public dietary recommendations of Vitamin D supplementation, smoking cessation, and weight reduction behaviors with further assessment of disease course among HS patients.

Insuficiência de vitamina D e fatores associados: um estudo com idosos assistidos por serviços de atenção básica à saúde

Resumo O objetivo deste artigo é analisar a insuficiência de vitamina D e fatores associados em idosos assistidos na atenção primária à saúde. Trata-se de um estudo transversal que avaliou 533 idosos (≥ 60 anos) em três cidades do estado de São Paulo, Brasil. Foi avaliada a 25-hidroxivitamina D (25 OH D) sérica por quimioluminescência. Os fatores avaliados foram condições sociodemográficas (sexo, faixa etária, etnia, escolaridade, renda, estado civil), de saúde (doenças referidas), composição corporal (IMC, circunferência da cintura), estilo de vida (atividade física e tabagismo) e exposição solar (finalidade, duração, frequência e horário de exposição, partes expostas, uso de protetor solar, tipo de pele). A prevalência de insuficiência foi de 64,5%, com associação para sexo feminino, etnia não brancos/não declarados, baixo peso, circunferência da cintura elevada (risco para DCV) e inatividade física. Houve associação negativa para exposição solar habitual de mãos, braços e pernas, durante atividade de lazer, deslocamentos diários e atividade física e entre as 9h e 15h. Os achados mostram a relevância de fatores como sexo, etnia, composição corporal, atividade física e hábitos de exposição solar na alta prevalência de níveis inadequados de vitamina D em idosos.

VITAMIN D STATUS IN A HEALTHY TUNISIAN POPULATION

Background

Vitamin D deficiency is one of the most common medical conditions worldwide. In Tunisia, several studies evaluated Vitamin D status, but this was concerning specific populations (pregnant women, obese or diabetic patients and children with asthma). The only study that evaluated Vitamin D status in a healthy Tunisian population was conducted by Meddeb and associeties in 2002. The update of data available, based on the currently recommended limits, is necessary. This study aimed to estimate the prevalence of hypovitaminosis D in a healthy Tunisian population, and correlate the values with potential risk factors.

Methods

It was conducted on 209 Tunisian healthy subjects. Data collected included clinical characteristics and dietary intakes. We measured 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), glycemia, creatinine, calcium, phosphorus, and alkaline phosphatase concentrations. Hypovitaminosis D was retained for 25(OH)D concentrations <75 nmol/L. Vitamin D deficiency was defined by 25(OH)D concentrations <25 nmol/L.

Results

The prevalence of hypovitaminosis D and vitamin D deficiency were respectively 92.3% and 47.6%. The main factors that were significantly associated with low vitamin D levels in our multivariate analysis were veiling, living in rural areas and sunscreen use. However, sex, age, socioeconomic level, phototype, solar exposure score, smoking and bone mass index, were not statistically associated with hypovitaminosis D. The study of relationship between vitamin D status and serum PTH levels showed a significative and negative correlation (P < 0.005).

Conclusions

Given the high prevalence of vitamin D, an adapted health policy is essential. A widespread vitamin D supplementation and food fortification seems to be necessary in Tunisia.

Vitamin D status is favorably associated with the cardiovascular risk factors in adults with obesity

BACKGROUND & AIMS

Previous investigations have been indicated that vitamin D deficiency is an amendable risk for cardiovascular disease (CVD) in the general populations. Limited data is available concerning the relationship of vitamin D status and risk factors of CVD in the individuals with obesity and the existing data are highly controversial. We investigated whether serum vitamin D situation is related to multiple traditional CVD risk factors in Iranian obese subjects.

METHODS

A cross-sectional study was done among 214 Iranian adults with obesity (94 males and 120 females) aged 20-60 years, who attended the specialized outpatient clinics in Zabol city. Participants were categorized as vitamin D sufficient, insufficient, and deficient according to their serum 25(OH)D concentrations. Afterward, the presence of hypercholesterolemia, hypertriglyceridemia, low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C) as well as diabetes, hypertension, and high serum concentrations of high-sensitivity C-reactive protein (hs-CRP) as CVD risk factors were evaluated in the participants.

RESULTS

There was a noticeable regular trend regarding hypercholesterolemia (p = 0.008), high LDL-C (p = 0.024), hypertension (p = 0.021), and high hs-CRP (p < 0.0001) across various categories of vitamin D status. In adjusted model, vitamin D-deficient subjects were at higher risk for having hypercholesterolemia (OR: 3.22, p = 0.031), high LDL-C (OR: 2.37, p = 0.047), hypertension (OR: 2.32, p = 0.042), and high hs-CRP (OR: 5.49, p = 0.001) than ones with sufficient vitamin D status.

CONCLUSIONS

Vitamin D deficiency in obese subjects was found to be strongly related to higher risk of unfavorable lipid profile, hypertension, and high hs-CRP.

Gender difference in the relationship between anemia and vitamin D in Korean adults: the fifth Korea National Health and Nutrition Examination Survey

This study was conducted to assess the relationship between vitamin D deficiency and anemia, by gender, in Korean adults. The data of 16,060 adults were analyzed (men, 6,840; premenopausal women, 4,916; postmenopausal women, 4,340) from the fifth Korean National Health and Nutrition Examination Survey (KNHANES V) (2010–2012). There were several key findings. First, after adjusting for related variables, the odds ratio (OR) of anemia [hemoglobin (Hb) <13 g/dl in men or Hb <12 g/dl in women] using the vitamin D normal group {25-hydroxyvitamin [25(OH)D] ≥15.0 ng/ml} as reference, was significant for the vitamin D deficient group [25(OH)D <15.0 ng/ml] in the overall population [OR, 1.310; 95% confidence interval (CI), 1.168–1.470]. Second, the OR of anemia, using the vitamin D normal group as reference, was significant for the vitamin D deficient group in premenopausal women (OR, 1.293; 95% CI, 1.105–1.513). However, vitamin D deficiency in the vitamin D normal group in men (OR, 1.093; 95% CI, 0.806–1.484) and postmenopausal women (OR, 1.130; 95% CI, 0.906–1.409) was not significant. In conclusion, Vitamin D deficiency is positively associated with anemia in premenopausal women, but not in men and postmenopausal women.

Low serum 25-Hydroxy (OH) vitamin D levels are associated with increased arterial stiffness in healthy children: An echocardiographic study from Turkey

OBJECTIVE

Arterial stiffness refers to arterial wall rigidity, particularly in central vessels, and is an independent predictor of cardiovascular disease in many chronic diseases. 25-Hydroxy (OH) vitamin D has beneficial effects on blood pressure, vascular endothelial function, and arterial stiffness; most importantly, its deficiency is common worldwide. Therefore, we aimed to elucidate the role of 25-OH vitamin D deficiency in arterial stiffness development and its relationship with arterial stiffness in healthy children.

METHODS

This study included 80 patients with low levels of 25-OH vitamin D and 40 healthy control subjects. The study participants were then divided into three groups: group 1 consisted of patients with a deficient 25-OH D level of < 19.9 ng/ml, group 2 with an insufficient 25-OH D level between 20 and 29.9 ng/ml; group 3 were considered control group with a sufficient serum 25-OH vitamin D level of ≥30 ng/ml. Aortic strain, distensibility, stiffness index, and standard left ventricular measurements were calculated using M-mode echocardiographic data.

RESULTS

Left ventricular mass index (LVMI) and inter-ventricular septal diastolic thickness (IVST) appeared to increase in group 1 compared to groups 2 and 3. Aortic strain and distensibility were significantly decreased in group 1, whereas aortic stiffness index and elastic modulus were significantly increased. The aortic stiffness index was negatively correlated with serum 25-OH vitamin D levels; however, aortic strain, aortic distensibility, and LVMI were positively correlated.

CONCLUSIONS

Our study results revealed a significant relationship between 25-OH vitamin D levels indicative of a deficiency and aortic stiffness. Hence, we suggest that arterial stiffness may also occur in healthy children with a 25-OH vitamin D deficiency. Future in-depth studies are needed to understand the exact mechanisms underlying the aortic stiffness development associated with 25-OH vitamin D deficiency.

Vitamin D oral intermittent treatment (DO IT) study, a randomized clinical trial with individual loading regimen

Comparison of several regimens of oral vitamin D including an individually calculated loading regimen with the aim of achieving serum values > 75 nmol/l. Interventional, randomized, 3-arm study in vitamin D-deficient outpatients. Participants were allocated to supplementation of 24,000 IU vitamin D monthly over three months, using either a monthly drinking solution (Vi-De 3) or capsule (D3 VitaCaps), or an individualized loading regimen with the capsules taken weekly. For the loading regimen, the cumulative dose was calculated according to baseline 25-hydroxy-vitamin D (25(OH)D) serum value and body weight. Main inclusion criteria were age ≥ 18 years and 25(OH)D serum concentration < 50 nmol/l. The primary outcome was 25(OH)D serum concentration one week after treatment termination. Secondary endpoints were patient's preferences and adverse events. Full datasets were obtained from 52 patients. Mean 25(OH)D values were statistically significant higher after a loading regimen compared to a monthly administration of 24,000 IU vitamin D (76.4 ± 15.8 vs 61.4 ± 10.8 nmol/l; p < 0.01). All patients treated with the loading regimen reached sufficient 25(OH)D values > 50 nmol/l. Serum 25(OH)D values > 75 nmol/l were observed more frequently in patients taking the loading regimen (47% vs 11% drinking solution vs 12% capsules). Vitamin D-related adverse effects did not occur in any treatment groups. Capsules were preferred by 88.5% of the patients. Compared to treatments with monthly intake of 24,000 IU vitamin D, the intake of an individually calculated weekly loading regimen was able to raise serum concentrations > 50 nmol/l in all cases within a safe range.

Analysis of the Impact of Selected Vitamins Deficiencies on the Risk of Disability in Older People

Vitamin deficiencies have a serious impact on healthy aging in older people. Many age-related disorders have a direct or indirect impact on nutrition, both in terms of nutrient assimilation and food access, which may result in vitamin deficiencies and may lead to or worsen disabilities. Frailty is characterized by reduced functional abilities, with a key role of malnutrition in its pathogenesis. Aging is associated with various changes in body composition that lead to sarcopenia. Frailty, aging, and sarcopenia all favor malnutrition, and poor nutritional status is a major cause of geriatric morbidity and mortality. In the present narrative review, we focused on vitamins with a significant risk of deficiency in high-income countries: D, C, and B (B6/B9/B12). We also focused on vitamin E as the main lipophilic antioxidant, synergistic to vitamin C. We first discuss the role and needs of these vitamins, the prevalence of deficiencies, and their causes and consequences. We then look at how these vitamins are involved in the biological pathways associated with sarcopenia and frailty. Lastly, we discuss the critical early diagnosis and management of these deficiencies and summarize potential ways of screening malnutrition. A focused nutritional approach might improve the diagnosis of nutritional deficiencies and the initiation of appropriate clinical interventions for reducing the risk of frailty. Further comprehensive research programs on nutritional interventions are needed, with a view to lowering deficiencies in older people and thus decreasing the risk of frailty and sarcopenia.

The Prevalence of Vitamin D and Calcium Supplement use and Association with Serum 25-Hydroxy-vitamin D (25(OH)D) and Demographic and Socioeconomic Variables in Iranian Elderly

AIMS

The objective of this study was to determine the prevalence of vitamin D and calcium supplement use, and association with serum 25-hydroxy-vitamin D(25(OH)D) and demographic and socioeconomic variables in Iranian elderly.

SETTINGS AND DESIGN

This cross-sectional study was conducted in health centers of Tehran, capital of Iran.

METHODS

A total of 600 men and women were recruited using a two-stage cluster sampling method from 60 health centers. Participant's inclusion criteria included enrolling older adults over 60 years old who able to answer questions. We used valid and reliable questionnaires to record dietary intake of vitamin D and calcium. Any dietary supplements which included vitamin D/calcium were recorded. 25(OH)D level was measured. Participants were categorized as supplement users if they had taken supplements during last month.

RESULTS

The mean age of participants was 67.16 ± 6.07 years. Vitamin D supplements were used more often by females (OR = 11.89, 95% confidence interval (CI): 4.82-29.34), high educated subjects (OR = 3.49, 95% CI: 1.45-8.44), participants who did more physical activities (OR = 2.75, 95% CI: 1.52-5.00), and subjects who took antiosteoporosis medications (OR = 6.90, 95% CI: 2.84‑16.78). Calcium supplements were used more often by females (OR = 13.05, 95% CI: 5.19-32.81), more physical activities participants (OR = 2.17, 95% CI: 1.20-3.92), and antiosteoporosis users (OR = 8.31, 95% CI: 3.43-20.14). Significant positive associations were seen between 25(OH) D levels and osteoporosis (P = 0.020), vitamin D supplement use (P < 0.0001), and sun exposure (P = 0.093).

CONCLUSION

In this population of Tehranian adults, the prevalence of vitamin D and calcium supplement use may be attributed to educational level and underlying disease. Vitamin D supplementation, osteoporosis, and sun exposure were the strong predictors of vitamin D status.

Vitamin D and cardiovascular health

The principal source of vitamin D in humans is its biosynthesis in the skin through a chemical reaction dependent on sun exposure. In lesser amounts, the vitamin can be obtained from the diet, mostly from fatty fish, fish liver oil and mushrooms. Individuals with vitamin D deficiency, defined as a serum level of 25 hydroxyvitamin D < 20 ng/dl, should be supplemented. Vitamin D deficiency is a prevalent global problem caused mainly by low exposure to sunlight. The main role of 1,25 dihydroxyvitamin D is the maintenance of calcium and phosphorus homeostasis. However, vitamin D receptors are found in most human cells and tissues, indicating many extra-skeletal effects of the vitamin, particularly in the immune and cardiovascular (CV) systems. Vitamin D regulates blood pressure by acting on endothelial cells and smooth muscle cells. Its deficiency has been associated with various CV risk factors and appears to be linked to a higher mortality and incidence of CV disease (CVD). Several mechanisms have been proposed relating vitamin D deficiency to CV risk factors such as renin-angiotensin-aldosterone system activation, abnormal nitric oxide regulation, oxidative stress or altered inflammatory pathways. However, in the latest randomized controlled trials no benefits of vitamin D supplementation for CVD have been confirmed. Although more work is needed to establish the protective role of vitamin D in this setting, according to current evidences vitamin D supplements should not be recommended for CVD prevention.

Vitamin D and Kidney Diseases: A Narrative Review

Vitamin D (Vit. D) is among the most important elements of the human body that play pivotal roles in health and disease. It belongs to the fat-soluble secosteroid family, which is provided by either foods or direct exposure to sunlight that converts 7-hydroxycholesterol to the Vit. D precursor. An alternative step is bio-activation, which delivers an active form of Vit. D (Vit. D3), which participates in various noticeable functions including calcium regulation, bone remodeling, fertility, glucose control, and detoxification. The most recent literature is carefully reviewed (2049 articles) and the relative information was collected and discussed meticulously. Inclusion criteria were the articles that mentioned the relationship between Vit. D, adipokine, and kidney disease and exclusion criteria were nonrelevant articles. Vit. D plays several roles in the normal function of the kidney and metabolism. It has been revealed that Vit. D has a crucial impact on kidney disease and that its deficiency leads to kidney dysfunction and further renal disorder. Apart from the direct relationship of Vit. D with kidney disease, the association of adipocytes and adipokines with Vit. D and kidney function has also been studied. The noticeable role of Vit. D in kidney disease is investigated in various studies. It has been found that Vit. D has a pivotal role in kidney function and metabolism. Further study can reveal the better-detailed information about the exact relation of Vit. D and kidney disorders. The aim of the review was to provide a better insight into the exact role of Vit. D and adipokine in the kidney disease.

Vitamin D status in adults and children in Transcarpathia, Ukraine in 2019

Background

Vitamin D deficiency is a global health problem, it is assessed by measuring serum 25-hydroxivitamin D (25(OH) D), nevertheless epidemiological data for many countries remains underreported.

Objectives

To study the prevalence of vitamin D deficiency throughout the calendar year in a large cohort recruited ina multiethnic Transcarpathian region of Ukraine.

Methods

In this retrospective study 25(OH) D serum concentration was measured during all 12 months of the year 2019 by electrochemoluminescent assay on the automatic analyzer Cobas e411 in 1823 subjects, including both children and adults (1551 females (85.03%) and 273 males (14.97%)).

Results

The mean 25(OH) D concentration in adults demonstrates significantly lower levels compared to children (22.67 ± 8.63 ng/ml vs. 26.00 ± 10.72 ng/ml respectively, p < 0.001). Adult women expressed significantly lower mean annual serum 25 (OH) D concentrations in comparison to men (22.29 ± 8.46 ng/ml vs. 25.75 ± 9.38 ng/ml respectively, p < 0.001). In contrast, children did not show a significant difference between sexes (girls 24.98 ± 10.38 ng/ml vs. boys 27.01 ± 11.01 ng/ml, p = 0.2003). In the winter months, 25(OH) D levels fell below 20 ng/ml in 51,74% of adult population of Thranscarpathia, and in 12.91%, − below 12 ng/ml.

Conclusions

The results of this study contradict the previously reported evaluations of the vitamin D levels in Ukraine which were assessed by measuring serum 25(OH) D. Specifically, only approximately half of the studied population is vitamin D deficient during winter season. This study features the most representative sample size in Ukraine to date.

Effects of androgen excess and glucocorticoid exposure on bone health in adult patients with 21-hydroxylase deficiency

CONTEXT

This study aimed to determine the role of modifiable predictors on bone health in congenital adrenal hyperplasia (CAH).

DESIGN

Cross-sectional, single center study, including 97 patients (N = 42 men) with classic CAH due to 21-hydroxylase deficiency (N = 65 salt wasting, N = 32 simple virilizing).

MAIN OUTCOME MEASURES

Treatment-related predictors of bone health.

RESULTS

Average T scores (-0.9 ± 1.4 vs. -0.4 ± 1.4; p = 0.036) as well as Z scores (-1.0 ± 1.3 vs. -0.1 ± 1.4; p = 0.012) at the spine in patients with CAH were significantly lower in men than women. While osteoporosis was rare in women, it was documented in 9.1% of men with CAH. There was a significant positive correlation of Z scores at the spine with advancing age in women with CAH (R² = 0.178; p = 0.003). In multivariate analysis, the intake of conventional hydrocortisone (HC) instead of synthetic glucocorticoids was independently associated with a higher bone mineral density (BMD) at the hip region in both sexes. In women, there was a positive association with vitamin D concentrations. Interestingly, higher sodium levels were associated with a lower BMD independent of renin levels and fludrocortisone dosage. Neither in men nor in women, markers of androgen control were predictive for BMD at any site. Markers of bone turnover indicated low bone turnover. No pathological fractures were documented.

CONCLUSIONS

Men with CAH are particularly prone to low bone density, while women seem to be relatively protected by androgen excess compared to the general female population. The use of HC instead of synthetic GCs for hormone replacement may translate into better bone health.

Does vitamin D deficiency predict tumour malignancy in patients with bone tumours? Data from a multi-center cohort analysis

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Vitamin D deficiency is common in patients with bone tumours.

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Potential association between pre-diagnostic vitamin D status and tumour malignancy in patients with bone tumours.

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25(OH)D status should routinely be assessed and monitored in patients with bone tumours.

Vitamin D deficiency is a global health concern that is estimated to afflict over one billion people globally. The major role of vitamin D is that of a regulator of calcium and phosphate metabolism, thus, being essential for proper bone mineralisation. Concomitantly, vitamin D is known to exert numerous extra-skeletal actions. For example, it has become evident that vitamin D has direct anti-proliferative, pro-differentiation and pro-apoptotic actions on cancer cells. Hence, vitamin D deficiency has been associated with increased cancer risk and worse prognosis in several malignancies. We have recently demonstrated that vitamin D deficiency promotes secondary cancer growth in bone. These findings were partly attributable to an increase in bone remodelling but also through direct effects of vitamin D on cancer cells. To date, very little is known about vitamin D status of patients with bone tumours in general. Thus, the objective of this study was to assess vitamin D status of patients with diverse bone tumours. Moreover, the aim was to elucidate whether or not there is an association between pre-diagnostic vitamin D status and tumour malignancy in patients with bone tumours.

In a multi-center analysis, 25(OH)D, PTH and calcium levels of 225 patients that presented with various bone tumours between 2017 and 2018 were assessed. Collectively, 76% of all patients had insufficient vitamin D levels with a total mean 25(OH)D level of 21.43 ng/ml (53.58 nmol/L). In particular, 52% (117/225) of patients were identified as vitamin D deficient and further 24% of patients (55/225) were vitamin D insufficient. Notably, patients diagnosed with malignant bone tumours had significantly lower 25(OH)D levels than patients diagnosed with benign bone tumours [19.3 vs. 22.75 ng/ml (48.25 vs. 56.86 nmol/L); p = 0.04).

In conclusion, we found a widespread and distressing rate of vitamin D deficiency and insufficiency in patients with bone tumours. However, especially for patients with bone tumours sufficient vitamin D levels seem to be of great importance. Thus, we believe that 25(OH)D status should routinely be monitored in these patients. Collectively, there should be an increased awareness for physicians to assess and if necessary correct vitamin D status of patients with bone tumours in general or of those at great risk of developing bone tumours.

Evidence of protective role of Ultraviolet-B (UVB) radiation in reducing COVID-19 deaths

Prior studies indicate the protective role of Ultraviolet-B (UVB) radiation in human health, mediated by vitamin D synthesis. In this observational study, we empirically outline a negative association of UVB radiation as measured by ultraviolet index (UVI) with the number of COVID-19 deaths. We apply a fixed-effect log-linear regression model to a panel dataset of 152 countries over 108 days (n = 6524). We use the cumulative number of COVID-19 deaths and case-fatality rate (CFR) as the main dependent variables and isolate the UVI effect from potential confounding factors. After controlling for time-constant and time-varying factors, we find that a permanent unit increase in UVI is associated with a 1.2 percentage points decline in daily growth rates of cumulative COVID-19 deaths [p < 0.01] and a 1.0 percentage points decline in the CFR daily growth rate [p < 0.05]. These results represent a significant percentage reduction in terms of daily growth rates of cumulative COVID-19 deaths (− 12%) and CFR (− 38%). We find a significant negative association between UVI and COVID-19 deaths, indicating evidence of the protective role of UVB in mitigating COVID-19 deaths. If confirmed via clinical studies, then the possibility of mitigating COVID-19 deaths via sensible sunlight exposure or vitamin D intervention would be very attractive.

Oral intermittent vitamin D substitution: influence of pharmaceutical form and dosage frequency on medication adherence: a randomized clinical trial

Background

To assess adherence to and preference for vitamin D substitution with different pharmaceutical forms and frequencies of administration.

Methods

A focus group of stakeholders aimed at preparing the design of an interventional, randomized, cross-over study with 2 × 2 groups obtaining monthly or weekly vitamin D products in liquid or solid form for 3 months each. Dosage corresponds to cumulated amount of recommended 800 IU daily (5.600 IU weekly / 24.000 IU monthly). Main inclusion criteria were a vitamin D serum value < 50 nmol/l and age ≥ 18 years. Primary endpoint was adherence, secondary endpoints were preferences and vitamin D serum levels.

Results

The focus group reached consensus for preference of a monthly administration of solid forms to adults.

Full datasets were obtained from 97 participants. Adherence was significantly higher with monthly (79.5–100.0%) than weekly (66.4–98.1%) administration. Vitamin D levels increased significantly (p < 0.001) in all participants. An optimal value of > 75 nmol/l was achieved by 32% after 3 months and by 50% after 6 months. Preferred formulation was solid form (tablets, capsules) for 71% of participants, and preferred dosage frequency was monthly for 39% of participants.

Conclusions

Monthly oral vitamin D in solid form lead to the highest adherence, and is preferred by the participants. However, only one third of study participants achieved values in the optimal range of > 75 nmol/l cholecalciferol using weekly or monthly administration providing an average daily cholecalciferol dose of 800 IU.

Trial registration

NCT03121593 | SNCTP000002251. Registered 30. May 2017,. Prospectively registered.

Determination of serum 25-hydroxyvitamin D status among population in southern China by a high accuracy LC-MS/MS method traced to reference measurement procedure

Objective

We aimed to describe the 25-hydroxyvitamin D (25(OH)D) status of southern Chinese individuals by a high-accuracy liquid chromatography tandem mass spectrometry (LC-MS/MS) method which can trace to reference measurement procedure.

Materials and methods

From January 2018 to June 2019, a total of 4775 southern Chinese individuals were evaluated in our study. The serum levels of parathyroid hormone (PTH) were detected simultaneously in 162 cases. 25(OH)D was determined by LC-MS/MS, and PTH was detected using routine automated analysers. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D in males and females of different age groups were studied.

Results

The mean 25(OH)D concentration in our study was 32.57 ng/mL (4.20-101.40 ng/mL). The global 25(OH)D concentration in males was higher than that in females of different age group. The prevalence of vitamin D deficiency (< 20 ng/mL) in females (16.65%) was higher than that in males (6.83%). The prevalence of vitamin D deficiency (< 20 ng/mL) was most common in winter (22.98% of all women and 15.49% of all men). 25(OH)D concentrations were higher in those from whom blood samples were collected in summer and autumn than in winter and spring. 25(OH)D₂ was detected in 672 serum samples (14.07%). In addition, there was a negative correlation between the concentrations of 25(OH)D and serum PTH (r = - 0.149, P < 0.05).

Conclusion

Our study demonstrated that the average serum 25(OH)D concentration in southern Chinese individuals was higher than that in other Chinese cohorts by a high-accuracy LC-MS/MS method. The global 25(OH)D concentration in males was higher than that in females of different ages, and the prevalence of vitamin D deficiency in females was higher than that in males. Seasonal change was an important aspect of 25(OH)D concentration in young and middle-aged people but became less relevant for that in older subjects. 25(OH)D₂ detection was of minor practical significance in our study. In addition, we also found that there was a negative correlation between the serum levels of 25(OH)D and PTH in southern Chinese individuals.

Elevated Levels of 1,25-Dihydroxyvitamin D in Plasma as a Missing Risk Factor for Celiac Disease

The prevalence of celiac disease (CD) has increased significantly in some developed countries in recent decades. Potential risk factors that have been considered in the literature do not appear to provide a convincing explanation for this increase. This has led some researchers to hypothesize that there is a "missing environmental factor" that increases the risk of CD. Based on evidence from the literature, the author proposes that elevation in plasma levels of 1,25-dihydroxyvitamin D [1,25(OH)₂D] is a missing risk factor for CD, and relatedly that significant oral vitamin D exposure is a "missing environmental factor" for CD. First, elevated plasma levels of 1,25(OH)₂D are common in CD, especially in the newly diagnosed. Second, nine distinct conditions that increase plasma levels of 1,25(OH)₂D are either associated with CD or have indications of such an association in the literature. Third, a retrospective study shows that sustained oral vitamin D supplementation in infancy is associated with increased CD risk, and other studies on comorbid conditions support this association. Fourth, large doses of oral vitamin D upregulate many of the same cytokines, chemokines, and toll-like receptors that are upregulated in CD. Fifth, epidemiological evidence, such as the timing of the inception of a CD "epidemic" in Sweden, the increased prevalence of CD in Finland and the United States in recent decades, the unusually low prevalence of CD in Germany, and the differential in prevalence between Finnish Karelians and Russian Karelians, may all be explained by oral vitamin D exposure increasing CD risk. The same is true of some seemingly contradictory results in the literature on the effects of breastfeeding on CD risk. If future research validates this hypothesis, adjustments to oral vitamin D consumption among those who have genetic susceptibility may decrease the risk of CD in these individuals.

The association between circulating 25-hydroxyvitamin D and cardiovascular diseases: a meta-analysis of prospective cohort studies

BACKGROUND

There is a controversy about the association between vitamin D and cardiovascular diseases (CVDs). The effect of serum 25-OH-vitD on the risk of CVDs was evaluated.

METHODS

Major electronic databases including Scopus, Science Direct, and PubMed were searched. All prospective cohort studies on the relationship between vitamin D status and CVDs conducted between April 2000 and September 2017 were included, regardless language. The study participants were evaluated regardless of their age, sex, and ethnicity. The Newcastle-Ottawa Scale was used to assess the quality of the studies. Two investigators independently selected the studies and extracted the data. The designated effects were risk ratio (RR) and hazard ratio (HR). The random effects model was used to combine the results.

RESULTS

A meta-analysis of 25 studies with 10,099 cases of CVDs was performed. In general, a decrease in the level of vitamin D was associated with a higher relative risk of CVDs (incidence-mortality combined) (RR = 1.44, 95% CI: 1.24-1.69). This accounts for 54% of CVDs mortality rate (RR = 1.54, 95% CI: 1.29-1.84(. However, no significant relationship was observed between the vitamin D status and incidence of CVDs (RR = 1.18, 95% CI: 1-1.39). In general, low serum vitamin D level increased the risk of CVD by 44% (RR = 1.44, 95% CI: 1.24-1.69). It also increased the risk of CVD mortality (RR = 1.54, 95% CI: 1.29-1.84) and incidence rates (RR = 1.18, 95% CI: 1-1.39).

CONCLUSIONS

The findings showed that vitamin D deficiency increases the CVDs mortality rate. Due to the limited number of studies on patients of the both genders, further research is suggested to separately evaluate the effect of vitamin D status on CVD in men and women.

A Critical Appraisal of Strategies to Optimize Vitamin D Status in Germany, a Population with a Western Diet

During the last decade, our scientific knowledge of the pleiotropic biological effects of vitamin D metabolites and their relevance to human health has expanded widely. Beyond the well-known key role of vitamin D in calcium homeostasis and bone health, it has been shown that vitamin D deficiency is associated with a broad variety of independent diseases, including several types of cancer, and with increased overall mortality. Moreover, recent findings have demonstrated biological effects of the vitamin D endocrine system that are not mediated via activation of the classical nuclear vitamin D receptor (VDR) by binding with high affinity to its corresponding ligand, the biologically active vitamin D metabolite 1,25-dihydroxyvitamin D (1,25(OH)₂D). In contrast, many of these new biological effects of vitamin D compounds, including regulation of the circadian clock and many metabolic functions, are mediated by other vitamin D metabolites, including 20-hydroxyvitamin D and 20,23-dihydroxyvitamin D, and involve their binding to the aryl hydrocarbon receptor (AhR) and retinoid-orphan receptor (ROR). In most populations, including the German population, UVB-induced cutaneous vitamin D production is the main source for fulfilling the human body’s requirements of vitamin D. However, this causes a dilemma because solar or artificial UVR exposure is associated with skin cancer risk. In addition to UVB-induced vitamin D production in skin, in humans, there are two other possible sources of vitamin D: from diet and supplements. However, only a few natural foods contain substantial amounts of vitamin D, and in most populations, the dietary source of vitamin D cannot fulfill the body´s requirements. Because an increasing body of evidence has convincingly demonstrated that vitamin D deficiency is very common worldwide, it is the aim of this paper to (i) give an update of the vitamin D status in a population with a western diet, namely, the German population, and to (ii) develop strategies to optimize the vitamin D supply that consider both the advantages as well as the disadvantages/risks of different approaches, including increasing vitamin D status by dietary intake, by supplements, or by UVB-induced cutaneous synthesis of vitamin D.

Vitamin D Deficiency in Patients With Idiopathic and Traumatic Osteochondritis Dissecans of the Talus

BACKGROUND

Low vitamin D levels are common in patients with foot and ankle disorders. We have previously demonstrated that juveniles diagnosed with osteochondritis dissecans (OCD) have a high prevalence of vitamin D deficiency. Moreover, there is evidence that OCD might be related to vitamin D deficiency in general. However, whether or not hypovitaminosis D is associated with OCD of the talus has yet to be elucidated.

METHODS

The aim of this study was to determine serum vitamin D levels [25(OH)D] of patients diagnosed with traumatic and idiopathic OCD of the talus. The vitamin D status of patients was measured and correlated to age, sex, season, etiology, laterality, degree of disease, and nicotine abuse. Moreover, parathyroid hormone and serum calcium levels of patients were obtained to assess for severe vitamin D deficiency and secondary hyperparathyroidism. Between January 2015 and December 2017, 65 patients with a mean age of 38.9 years and a total of 68 lesions were identified.

RESULTS

In total, 75.4% of patients had low vitamin D levels with a mean overall 25(OH)D level of 24.2 ng/mL. Specifically, 35.4% of patients were vitamin D deficient; another 40% were vitamin D insufficient, and only 24.6% of patients presented with sufficient vitamin D levels. Statistical analysis showed no significant difference comparing vitamin D levels of patients with idiopathic OCD to patients with traumatic OCD.

CONCLUSION

We could not find any significant differences in the vitamin D status of patients with OCD of the talus compared with patients with foot and ankle disorders in general. However, we found that vitamin D deficiency was frequent in patients presenting with traumatic and idiopathic OCD of the talus. We believe it might be beneficial to routinely assess and treat the vitamin D status of patients.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Vitamin D history part III: the "modern times"-new questions for orthopaedic practice: deficiency, cell therapy, osteomalacia, fractures, supplementation, infections

PURPOSE

The nutritional basis for rickets was described between 1880 and 1915, at the same period of discovery of other "vital substances" or vitamins. In contrast, rickets could also be prevented or cured by sunshine. But as the capacity to produce vitamin D depends on exposure to ultraviolet B rays (UVB) from sunlight or artificial sources, vitamin D became one of the most frequently used "drugs" in the twentieth century to compensate for insufficient exposure to UVB of humans. Furthermore, as the understanding of vitamin D metabolism grew during the twentieth century, other concerns than rickets occurred for the orthopaedic surgeon: In recent history, deficiency is explored as being an associated factor of different bone pathologies as fracture or prosthetic infection. The aim of this review is to analyze these new data on vitamin D.

MATERIALS AND METHODS

During the twentieth century, there were many concerns for the orthopaedic surgeon: sources and synthesis of vitamin D, regulation of the calcium deposition process for both children and adults, when vitamin D deficiency is observed, and what the best method of vitamin D supplementation is. As target genes regulated by vitamin D are not limited to those involved in mineral homeostasis, orthopedists recently discovered that vitamin D might prevent periprosthetic infection.

RESULTS

The primary source (80%) of vitamin D is dermal synthesis related to the sun. Dietary sources (20%) of vitamin D are fat fishe, beef, liver, and eggs. Vitamin D is produced industrially to be used in fortified foods and supplements. Maintenance of skeletal calcium balance is mediated through vitamin D receptors. Progenitor cells, chondrocytes, osteoblasts, and osteoclasts contain these receptors which explains the role of vitamin D in cell therapy, in the prevention of rickets and osteomalacia. Despite fortified foods, the prevalence of deficiency remains endemic in north latitudes. However, the definition of vitamin D insufficiency or deficiency remains controversial. Vitamin D has been evaluated in patients undergoing fractures and elective orthopaedic procedures Although supplementation may not be able to prevent or cure all the orthopaedic pathologies, oral supplementation is able to improve the vitamin D levels of deficient patients. These vitamin D level improvements might be associated with better functional and clinical outcomes after some surgical procedures and improvement of immunity to decrease the risk of infection in arthroplasties.

CONCLUSION

Vitamin D deficiency is frequent and concerns millions of people in the world. It is therefore normal to find hypovitaminosis in various orthopaedic populations including trauma and arthroplasties. However, we do not know exactly if this phenomenon only reflects the general prevalence of vitamin D deficiency or has an influence on the outcome of some pathologies on specific populations at risk. After the success of treatment of rickets, it is disappointing that we are still wondering in the twenty-first century whether supplementation of a substance synthetized millions of years ago by plankton and necessary for growth of all the animals may improve (or not) clinical and functional outcomes of a simple fracture in humans.

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.

Serum vitamin D levels in Berliners of Turkish descent -a cross-sectional study

BACKGROUND

Vitamin D levels may differ between migrant and non-migrant populations, especially among non-western immigrants living in a country with limited sun exposure such as Germany. This study examined serum vitamin D concentration and associated factors among Berliners with and without Turkish background.

METHODS

Two samples (with and without Turkish roots) were recruited in the inner city of Berlin for a cross-sectional study assessing serum vitamin D concentration. Linear regression analyses were used to examine sociodemographic, lifestyle and medical factors associated with serum vitamin D levels.

RESULTS

In the analyses, we included 537 subjects (39% men and 61% women, age 43.2 ± 12.5 (mean ± standard deviation) years) with and 112 without Turkish background (46% men and 54% women, age 46.7 ± 14.6 years). The Turkish sample had lower mean (95%-Confidence Interval) vitamin D levels than the non-Turkish sample: 22.7 nmol/L (21.5;23.9) vs 34.7 nmol/L (31.9;37.5), p < 0.001. In the Turkish female subgroup, veiled women had considerably lower levels than unveiled women: 14.4 nmol/L (11.5;17.3) vs 24.9 nmol/L (23.1;26.7), p < 0.001. Multivariable regression analysis revealed that among the Berliners of Turkish descent, being active less than 150 min per day, and being overweight/obese were independently associated with a lower vitamin D concentration. In the non-migrant sample besides being overweight and obese, female sex was associated with lower vitamin D concentrations.

CONCLUSIONS

Serum vitamin D levels were considerably low in Berliners of Turkish descent, and especially in veiled women. Potentially modifiable factors of low vitamin D levels were high BMI and low physical activity. These findings should be considered in the development of future public health strategies for subpopulations with Turkish migration background.

Vitamin D status and its association with season, depression in stroke

BACKGROUND

Vitamin D plays a key role in depression. In this study, we aimed to assess the prevalence of vitamin D deficiency or insufficiency and the association between vitamin D status and depression in patients with acute stroke.

METHODS

From September 2013 to May 2015, consecutive patients with acute stroke were enrolled in this study within 7 days of symptom onset. Clinical information was collected during admission, and stroke severity was assessed at discharge. Depressive symptoms were measured by the 17-item Hamilton Rating Scale for Depression at 1 month after stroke. Based on the depressive symptoms, diagnoses of depression were made in accordance with DSM-IV criteria. Serum vitamin D levels were measured at admission. Binary logistic regression models were used to determine the association between depression and vitamin D levels treated as either absolute values (categorized as deficiency, insufficiency and sufficiency) or month-specific tertiles. Vitamin D levels were categorized by month-specific tertiles (high, intermediate, low) to reflect seasonal variation of serum vitamin D levels.

RESULTS

A total of 442 patients were enrolled in this study. The prevalence of vitamin D deficiency (< 30 nmol/L) or insufficiency (30-49.99 nmol/L) was 46%. The prevalence of vitamin D deficiency was significantly different in winter compared to summer months (p < 0.001). One hundred seven patients (26.6%) were diagnosed with depression at 1 month. In multivariable analyses, after fully adjusting for other potential confounders, the prevalence of depression was significantly higher in patients in the low tertile (odds ratio(OR) 2.24, 95% confidence interval (CI)1.18-4.26; p = 0.014) compared to the high tertile, and the prevalence of depression was also significantly higher in patients with vitamin D deficiency (OR 2.66, 95% CI 1.48-4.77; p = 0.001) and insufficiency (OR 1.93, 95% CI 1.00-3.74; p = 0.049) compared to those with vitamin D sufficiency.

CONCLUSIONS

Vitamin D deficiency and insufficiency occur at high rates in acute stroke patients. Low serum vitamin D levels were associated with depression in patients with acute stroke as analyzed by both the absolute level of vitamin D and month-specific tertiles. Intervention studies are needed to determine the benefits of vitamin D supplementation for depression in poststroke patients.

Immunomodulation by vitamin D

Vitamin D exerts several immunological functions in addition to its homeostatic functions on calcium and bone metabolism. Current data show that relative vitamin D deficiency (< 75 nmol/l 25-hydroxyvitamin D) as well as acquired seasonal vitamin D deficiency (< 50 nmol/l) are frequent in Germany. As confirmed by our own data, UV exposure plays a major role for maintenance of vitamin D status, e.g., in patients with UV-triggered diseases, vitamin D deficiency is more frequent, even throughout the year. The beneficial impact of vitamin D on immune functions is highlighted by epidemiologic, genetic, and experimental evidence. In the past years, numerous publications have presented associations between vitamin D deficiency, on the one hand, and severity and prevalence of allergic asthma in children and adults, on the other hand.

Seasonal plasticity of cognition and related biological measures in adults with and without Alzheimer disease: Analysis of multiple cohorts

BACKGROUND

There are few data concerning the association between season and cognition and its neurobiological correlates in older persons-effects with important translational and therapeutic implications for the diagnosis and treatment of Alzheimer disease (AD). We aimed to measure these effects.

METHODS AND FINDINGS

We analyzed data from 3,353 participants from 3 observational community-based cohort studies of older persons (the Rush Memory and Aging Project [MAP], the Religious Orders Study [ROS], and the Minority Aging Research Study [MARS]) and 2 observational memory-clinic-based cohort studies (Centre de Neurologie Cognitive [CNC] study at Lariboisière Hospital and the Sunnybrook Dementia Study [SDS]). We performed neuropsychological testing and, in subsets of participants, evaluated cerebrospinal fluid AD biomarkers, standardized structured autopsy measures, and/or prefrontal cortex gene expression by RNA sequencing. We examined the association between season and these variables using nested multiple linear and logistic regression models. There was a robust association between season and cognition that was replicated in multiple cohorts (amplitude = 0.14 SD [a measure of the magnitude of seasonal variation relative to overall variability; 95% CI 0.07-0.23], p = 0.007, in the combined MAP, ROS, and MARS cohorts; amplitude = 0.50 SD [95% CI 0.07-0.66], p = 0.017, in the SDS cohort). Average composite global cognitive function was higher in the summer and fall compared to winter and spring, with the difference equivalent in cognitive effect to 4.8 years' difference in age (95% CI 2.1-8.4, p = 0.002). Further, the odds of meeting criteria for mild cognitive impairment or dementia were higher in the winter and spring (odds ratio 1.31 [95% CI 1.10-1.57], p = 0.003). These results were robust against multiple potential confounders including depressive symptoms, sleep, physical activity, and thyroid status and persisted in cases with AD pathology. Moreover, season had a marked effect on cerebrospinal fluid Aβ 42 level (amplitude 0.30 SD [95% CI 0.10-0.64], p = 0.003), which peaked in the summer, and on the brain expression of 4 cognition-associated modules of co-expressed genes (m6: amplitude = 0.44 SD [95% CI 0.21-0.65], p = 0.0021; m13: amplitude = 0.46 SD [95% CI 0.27-0.76], p = 0.0009; m109: amplitude = 0.43 SD [95% CI 0.24-0.67], p = 0.0021; and m122: amplitude 0.46 SD [95% CI 0.20-0.71], p = 0.0012), which were in phase or anti-phase to the rhythms of cognition and which were in turn associated with binding sites for several seasonally rhythmic transcription factors including BCL11A, CTCF, EGR1, MEF2C, and THAP1. Limitations include the evaluation of each participant or sample once per annual cycle, reliance on self-report for measurement of environmental and behavioral factors, and potentially limited generalizability to individuals in equatorial regions or in the southern hemisphere.

CONCLUSIONS

Season has a clinically significant association with cognition and its neurobiological correlates in older adults with and without AD pathology. There may be value in increasing dementia-related clinical resources in the winter and early spring, when symptoms are likely to be most pronounced. Moreover, the persistence of robust seasonal plasticity in cognition and its neurobiological correlates, even in the context of concomitant AD pathology, suggests that targeting environmental or behavioral drivers of seasonal cognitive plasticity, or the key transcription factors and genes identified in this study as potentially mediating these effects, may allow us to substantially improve cognition in adults with and without AD.

LC-MS/MS based 25(OH)D status in a large Southern European outpatient cohort: gender- and age-specific differences

BACKGROUND

Developed countries have a high prevalence of vitamin D deficiency. In previous studies, 25(OH)D was predominantly measured by immunoassays. The present study assessed serum 25(OH)D in a very large Southern European outpatient cohort by liquid chromatography tandem mass spectrometry (LC-MS/MS).

MATERIALS AND METHODS

74,235 serum 25(OH)D results generated under routine conditions between 2015 and 2016 were extracted from the laboratory information system of the Department of Clinical Pathology at Bolzano Hospital (Italy). In 3801 cases, parathyroid hormone (PTH) was requested in parallel. Serum 25(OH)D was measured by a NIST-972 aligned commercial LC-MS/MS method. The distribution of serum 25(OH)D concentrations in males and females of different age groups, the prevalence of 25(OH)D₂ and seasonal variability were studied.

RESULTS

The average 25(OH)D concentration in the entire cohort was 68.6 nmol/L (7.5-1880 nmol/L). Females had a 7 nmol/L higher average 25(OH)D concentration than males, which increased significantly with age. 37.9 and 28.3% of males and females, respectively, had a deficient 25(OH)D concentration of < 50 nmol/L. 620 samples (0.84%) had measureable amounts of 25(OH)D₂. In samples with a normal PTH, 25(OH)D was 11 nmol/L higher than in the entire cohort. Seasonal variation ranged between 20 and 30% and was most pronounced in young individuals. 25(OH)D₂ remained constant throughout the year.

CONCLUSION

Average serum 25(OH)D in South Tyrol is higher than in other parts of Europe. 25(OH)D and PTH show a continuous inverse relationship. Seasonal variation of serum 25(OH)D is an important aspect in young and middle-aged adults, but becomes less relevant in elderly subjects. 25(OH)D₂ is of minor practical importance in South Tyrol.

Update of the tolerable upper intake level for vitamin D for infants

Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to revise the tolerable upper intake level (UL) for vitamin D for infants (≤ 1 year) set in 2012. From its literature review, the Panel concluded that the available evidence on daily vitamin D intake and the risk of adverse health outcomes (hypercalciuria, hypercalcaemia, nephrocalcinosis and abnormal growth patterns) cannot be used alone for deriving the UL for infants. The Panel conducted a meta-regression analysis of collected data, to derive a dose-response relationship between daily supplemental intake of vitamin D and mean achieved serum 25(OH)D concentrations. Considering that a serum 25(OH)D concentration of 200 nmol/L or below is unlikely to pose a risk of adverse health outcomes in infants, the Panel estimated the percentage of infants reaching a concentration above this value at different intakes of vitamin D. Based on the overall evidence, the Panel kept the UL of 25 μg/day for infants aged up to 6 months and set a UL of 35 μg/day for infants 6-12 months. The Panel was also asked to advise on the safety of the consumption of infant formulae with an increased maximum vitamin D content of 3 μg/100 kcal (Commission Delegated Regulation (EU) 2016/127 repealing Directive 2006/141/EC in 2020). For infants aged up to 4 months, the intake assessment showed that the use of infant formulae containing vitamin D at 3 μg/100 kcal may lead some infants to receive an intake above the UL of 25 μg/day from formulae alone without considering vitamin D supplemental intake. For infants aged 4-12 months, the 95th percentile of vitamin D intake (high consumers) estimated from formulae and foods fortified or not with vitamin D does not exceed the ULs, without considering vitamin D supplemental intake.

Implications of standardization of serum 25-hydroxyvitamin D data for the evaluation of vitamin D status in Germany, including a temporal analysis

BACKGROUND

Comparability of 25-hydroxyvitamin D (25(OH)D) measurements is hampered by method-related differences in measurement values. International standardization of laboratory assays has been suggested to solve this problem.

METHODS

As part of the European Commission-funded project 'Food-based solutions for optimal vitamin D nutrition and health through the life cycle' (ODIN), original measurements of serum 25(OH)D of three German national health surveys conducted between 1998 and 2011 have been standardized retrospectively. In these representative population-based samples including persons aged between 1 and 79 years, the original 25(OH)D values were compared with those after standardization. Mean values and prevalences of vitamin D deficiency, insufficiency, and sufficiency (25(OH)D levels < 30, 30- < 50, and > =50 nmol/l, respectively) were calculated by sex and age groups based on original and standardized 25(OH)D data.

RESULTS

In comparison to the original 25(OH)D levels, the standardized levels showed higher means overall and in age- and sex-specific analyses. After standardization, the prevalence of vitamin D deficiency was lower in all surveys while the prevalence of vitamin D sufficiency was higher. Nevertheless, even after standardization ~ 15% of adults and 12.5% of children had serum 25(OH)D levels < 30 nmol/l. Thus, the proportion of deficient vitamin D levels in the German population is still considerable.

CONCLUSIONS

The use of standardization of 25(OH)D levels has a substantial impact on estimates of the vitamin D status in Germany. Since clinical diagnostic, therapeutic and public health decision-making require valid and comparable data, standardization and calibration of commercial, clinical and research laboratory assays for 25(OH)D measurement should become common practice. Until then, researchers, health practitioners and policy makers should be aware of the peculiarities of the measurement methods when comparing and interpreting 25(OH)D levels.

Vitamin D levels in actinic keratosis: a preliminary study

BACKGROUND

Recent studies that investigated the effect of vitamin D on skin cancer risk have exhibited inconsistent results.

OBJECTIVE

The aim of the study was to evaluate vitamin D status in patients with actinic keratosis.

METHODS

A cross-sectional study was conducted on 31 patients with actinic keratosis and 29 healthy controls. Serum vitamin D levels in the study group were determined by liquid chromatography/tandem mass spectrometry.

RESULTS

Serum 25(OH)D levels in patients with actinic keratosis were significantly higher than those of the healthy controls (P=0.04). Prevalence of 25(OH)D deficiency was significantly higher in the healthy controls (75.9%) compared to the patients with actinic keratosis (54.8%), but the difference was not statistically significant (P= 0.09).

STUDY LIMITATIONS

The cross-sectional design of the study, data on smoking based on patient self-report, and subjects' different dietary habits, which can influence 25(OH)D levels, are the study's limitations.

CONCLUSION

Serum vitamin D level can be used as a marker for ultraviolet B radiation from sun exposure; therefore, it can be used in individuals at risk of actinic keratosis. Oral intake of vitamin D through diet or supplements is proposed instead of prolonged ultraviolet exposure to maintain adequate vitamin D serum levels. Further research is needed to elucidate the role of vitamin D in skin carcinogenesis.

Effect of vitamin D on the variability of blood pressure in premenopausal and menopausal hypertensive women in the area of Blida (Algeria)

OBJECTIVE

To evaluate the effect of 25 (OH) vitamin D supplementation on blood pressure (BP) variability in hypertensive women in the pre-menopausal and post-menopausal periods.

MATERIALS AND METHODS

881 hypertensive women prospectively followed for an interventional study between January 2016 and September 2017, in specialized consultation at the department of internal medicine at the Blida University Hospital (Algeria). Four hundred and thiry nine premenopausal women (group I) and 442 menopausal women (group II). The initial serum 25 (OH) D level for each group was determined by the enzyme immunoassay. In groups I and II, we identified 2 subgroups, A: insufficiency (vit D between 29 and 20ng/ml) and B: deficiency (vit D less than 20ng/L). Antihypertensive therapy was supplemented with an additional 200000IU/month cholecalciferol for the two B subgroups. The variability in BP was calculated as the ratio of mean systolic and diastolic BP during daytime and nighttime, with performing ambulatory BP measurement at baseline, 3, 6, and 12 months of follow-up.

RESULTS

At inclusion, the level of 25 (OH) D was lower (P<0.05) in subgroups IB (19.3±8.5ng/ml) and IIB (18.2±9, 5ng/ml) compared to subgroups IA (28.1±10.7ng/ml) and IIA (25.2±10.1ng/ml). After supplementation, the level of 25 (OH) D increased in subgroup IB (38.3±11.9ng/ml) and in subgroup IIB (37.3±10, 5ng/ml) and became higher (P<0.001) than in subgroups IA and IIA. Between subgroups IA and IB, at inclusion, there is no difference (P>0.05) in the SBP and DBP variability during the day and at night. After treatment, the variability of the SBP at night became lower (P<0.02) in group IB compared to group IA. In subgroup IIB, daytime variability indices were higher (P=0.04) at inclusion than in group IIA. After treatment, the variability of SBP during the day decreased but remained the highest (P<0.05) in subgroup IIB (14.8±10.8mmHg) compared to subgroup IB (12.0±8.1mmHg), as well as to subgroups IIA (10.9±9.8mmHg) and IA (10±8.1mmHg). We found a significant correlation of cholecalciferol with the variability of SBP during the day.

CONCLUSIONS

Vitamin D deficiency appears to be a factor of BP variability. Although the variability of the postmenopausal group remains higher than that of the other groups, the correction of the level of 25 (OH) D by the supply of cholecalciferol 200000 IU per month leads to a reduction in the variability of BP in the studied hypertensive women could help to prevent morbimortal complications.

Vitamin D and the Skin: An Update for Dermatologists

Vitamin D plays a key role in skeletal and cardiovascular disorders, cancers, central nervous system diseases, reproductive diseases, infections, and autoimmune and dermatological disorders. The two main sources of vitamin D are sun exposure and oral intake, including vitamin D supplementation and dietary intake. Multiple factors are linked to vitamin D status, such as Fitzpatrick skin type, sex, body mass index, physical activity, alcohol intake, and vitamin D receptor polymorphisms. Patients with photosensitive disorders tend to avoid sun exposure, and this practice, along with photoprotection, can put this category of patients at risk for vitamin D deficiency. Maintaining a vitamin D serum concentration within normal levels is warranted in atopic dermatitis, psoriasis, vitiligo, polymorphous light eruption, mycosis fungoides, alopecia areata, systemic lupus erythematosus, and melanoma patients. The potential determinants of vitamin D status, as well as the benefits and risks of vitamin D (with a special focus on the skin), will be discussed in this article.