The Biphasic Effect of Vitamin D on the Musculoskeletal and Cardiovascular System

Vitamin D Levels and Temporomandibular Disorders: A Bidirectional Two-Sample Mendelian Randomization Analysis

Objective

Growing researches explore vitamin D's role in temporomandibular disorders (TMDs), but the link between vitamin D and TMDs remains debated. To clarify the causal relationship, we conducted a Mendelian randomization (MR) analysis using data from genome-wide association studies (GWAS).

Subjects and Methods

The GWAS dataset of vitamin D (GWAS ID: ukb-d-30890_irnt; sample size: 329247) was obtained from the IEU Open GWAS project. And that of TMDs (GWAS ID: finn-b-TEMPORO; sample size: 134280), initiated on August 25th, 2017 and publicly released on December 18th, 2023, was extracted from the FinnGen dataset, whose cases were diagnosed based on the revised International Classification of Diseases, 10th Edition (ICD-10) code K07.6. Both datasets were obtained from the European population. According to three assumptions of MR analysis, a bi-directional MR analysis was performed to measure the causal relationship, with Inverse variance weighted (IVW) as the primary method and MR Egger and Weighted median as supplement. Moreover, diverse sensitivity analyses, including Cochran's Q test, MR Egger intercept, Mendelian randomized polymorphism RESidual Sum and Outlier (MR-PRESSO), and leave-one-out analysis, were used to verify the stability of the findings.

Results

The MR analysis supported causal effects of vitamin D levels on TMDs risks within the European population using IVW method [odds ratio = 1.316; 95% confidence interval = 1.086 to 1.595; P = 0.005], supported by MR Egger and Weighted median. While there was no indication that TMDs have a direct impact on vitamin D levels [β: -0.00738, standard error = 0.00665; P = 0.568].

Conclusion

The study revealed that within the European population higher levels of vitamin D led to higher risks of developing temporomandibular disorders, but found no obvious evidence that TMDs are causally associated with vitamin D. The conclusion should be cautiously interpreted, given the selection bias of TMDs patients sample.

Factors Associated with Vitamin D Deficiency and Their Relative Importance among Indian Adolescents: An Application of Dominance Analysis

Vitamin D deficiency is a serious issue in developing nations, including India. This study investigates the determinants of vitamin D deficiency among Indian adolescents and assesses their relative importance using dominance analysis. Data from the Comprehensive National Nutrition Survey (CNNS) conducted between 2016 and 2018 were utilized in this study. Vitamin D levels were assessed based on serum 25-hydroxyvitamin D concentration, with a sample size encompassing 13,065 adolescents aged between 10 and 19 years. Backward stepwise multivariate logistic regression was used to identify the correlates of vitamin D deficiency, and the relative importance of these factors was assessed using dominance analysis. The study identified nine predictors that were significantly associated with vitamin D deficiency at a 1% level of significance (α = 0.001). Among these factors, sex was found to be the most significant predictor, with female adolescents being 2.66 (95% CI: 95% CI: 2.39-2.96) times more likely to be vitamin D deficient compared to male adolescents. Lifestyle and behavioral factors, such as "sex," "wealth index," and "place of residence," were more dominant in predicting vitamin D deficiency than biological indicators like "BMI" and "serum creatinine." This underscores the vital role of sunlight exposure in maintaining sufficient vitamin D levels. In summary, this study sheds light on the multifaceted factors contributing to vitamin D deficiency among Indian adolescents, emphasizing the significance of targeted interventions and public health awareness campaigns to mitigate this pressing issue.

A comprehensive review on the impact of calcium and vitamin D insufficiency and allied metabolic disorders in females

Calcium is imperative in maintaining a quality life, particularly during later ages. Its deficiency results in a wide range of metabolic disorders such as dental changes, cataracts, alterations in brain function, and osteoporosis. These deficiencies are more pronounced in females due to increased calcium turnover throughout their life cycle, especially during pregnancy and lactation. Vitamin D perform a central role in the metabolism of calcium. Recent scientific interventions have linked calcium with an array of metabolic disorders in females including hypertension, obesity, premenstrual dysphoric disorder, polycystic ovary syndrome (PCOS), multiple sclerosis, and breast cancer. This review encompasses these female metabolic disorders with special reference to calcium and vitamin D deficiency. This review article aims to present and elaborate on available data regarding the worldwide occurrence of insufficient calcium consumption in females and allied health risks, to provide a basis for formulating strategies and population-level scientific studies to adequately boost calcium intake and position where required.

The effect of maternal vitamin D deficiency during pregnancy on glycolipid metabolism of offspring rats and the improvement of vitamin D intervention after weaning

Background

Vitamin D deficiency during pregnancy is common, but whether maternal vitamin D status affects glycolipid metabolism of offspring remains unclear.

Objective

To evaluate the effect of maternal vitamin D deficiency during pregnancy on the glycolipid metabolism of offspring at different life-cycles (from birth to adulthood) and to explore the improvement of different dosages of vitamin D supplementation.

Methods

Sprague-Dawley rats were fed vitamin D-deprived (VDD group) or standard vitamin D diets (SC group) during pregnancy, and their diets were changed to standard vitamin D diets during lactation (the offspring were sorted into VDDoffspring and SCoffspring groups). After weaning, rats in the VDDoffspring group were randomly assigned to the VDDoffspring, VDDoffspring-S3300 and VDDoffspring-S10000 groups with diets containing standard, medium and high dosages of vitamin D for 12 wk. Serum was collected for biochemical analyses at postnatal Day 21, postnatal Day 56 and postnatal Day 84. Oral glucose tolerance test (OGTT) was performed at postnatal Day 70.

Results

Compared to SCoffspring, rats in the VDDoffspring group had significantly lower birth weight with faster weight gain and higher levels of lipid metabolism in early life. After near adulthood, the differences in weight and lipid metabolism between the two groups disappeared. OGTT showed significantly higher blood glucose levels in the VDDoffspring group at 30 min, 60 min, and 90 min. The continuation of vitamin D supplementation at medium and high dosages after weaning did not cause any obvious changes in weight or glycolipid metabolism (except for postprandial hyperglycemia). OGTT demonstrated that the glucose levels in the VDDoffspring-S3300 group were lowest at all the time points and that those in the VDDoffspring-S10000 group were the highest at 30 min, 60 min, and 90 min among the three groups.

Conclusion

The adverse effects of vitamin D deficiency during pregnancy on glycolipid metabolism in offspring vary in different stages. Over a long time period, adequate vitamin D supplementation is beneficial to glycolipid metabolism for the offspring of subjects with vitamin D deficiency during pregnancy; however, further improvement is required.

The relationship of biochemical factors related to calcium metabolism with temporomandibular disorders

OBJECTIVE

The aim of this study is to investigate the relationship between calcium metabolism-related biochemical factors (alkaline phosphatase, vitamin D, parathyroid hormone (PTH), calcium, phosphorus and magnesium), and temporomandibular joint (TMJ) disk displacement with reduction (DDWR).

MATERIALS AND METHODS

This prospective observational study included patients with temporomandibular disorders (TMDs) (n = 50) and healthy controls (n = 50) of similar age and sex. The diagnosis of TMJ DDWR was made using the diagnostic criteria for temporomandibular joint disorders (DC/TMD). Both groups were compared in terms of serum alkaline phosphatase, 25 (OH) vitamin D, PTH, calcium, magnesium, and phosphorus levels. P<0.005 was accepted as a significant difference.

RESULTS

There was no significant difference between the groups in terms of age, gender, and body mass index (BMI). Calcium levels of patients with TMD were statistically significantly lower than control patients (p<0.05). While there was no significant difference between the two groups in terms of mean VIT D, the number of people with severe Vit D deficiency (<10 ng) in the TMD group was significantly higher than in the control group (p<0.05). There was no statistically significant difference between the groups in terms of serum alkaline phosphatase, magnesium, phosphorus and PTH levels.

CONCLUSION

The differences in serum calcium and vitamin D levels seen in the study indicate that biochemical factors related to calcium metabolism may be associated with TMJ DDWR. These results suggest that calcium and vitamin D deficiency should be evaluated and corrected in patients with TMD.

Analysis of hot trends in research on the association between vitamin D and cardiovascular disease

Objective

Vitamin D deficiency is the most common nutrient deficiency. Numerous studies suggest that vitamin D is an independent risk factor for cardiovascular disease. The objective is to visualize the research hotspots and evolution trends of the correlation between vitamin D and cardiovascular disease by using multivariate statistics and social network analysis techniques and to compare adult research with that of children in this field.

Methods

(Vitamin D [MeSH Major Topic]) AND (cardiovascular disease [MeSH Major Topic]) were retrieved from the PubMed database by time period. The bibliographic items co-occurrence matrix builder (BICOMB) was adopted to extract high-frequency subject terms and establish the core subject term co-occurrence matrix. With the Netdraw function of Ucinet 6.0 software, the social network of core subject terms was completed.

Results

Before 2010, there was a slow increase in the number of research papers covering all age groups in this field (157, 54, 84, and 211 papers were published in stages 1-4, respectively). From 2010 to 2020, there were 1,423 papers retrieved, showing a significantly increased research heat. The overall development trend of the research on the association between vitamin D and cardiovascular disease in children is similar to that in all age groups. From 2010 to 2020, 122 related papers were published (while before 2009, there were only 43 papers in all), presenting a good overall development trend. The social network analysis of core subject terms showed gradually increased correlations between research hotspots, from the early studies limited on the physiological function of vitamin D in cardiovascular diseases, to the role of vitamin D in the comorbidities of various cardiovascular diseases and its value as an intervention measure. Researches on the association between vitamin D and cardiovascular disease has a good overall development trend. Study of the mechanisms and the role of vitamin D in the common co-morbidities of cardiovascular disease and its therapeutic value will be the focus of future research.

Temporomandibular Disorders and Vitamin D Deficiency: What Is the Linkage between These Conditions? A Systematic Review

Although a growing body of literature has been emphasizing the role of vitamin D in oral health, there is still a gap of knowledge regarding the correlation between temporomandibular disorders (TMDs) and vitamin D. Therefore, the aim of this systematic review was to assess the linkage between hypovitaminosis D and TMDs to map the current literature in this field. On 10 September 2022, PubMed, Scopus, and Web of Science databases were systematically searched from the date of their inception to identify the studies that had assessed patients with TMDs. The primary outcome assessed in this review was the relationship between hypovitaminosis D and TMDs. Out of the 329 studies identified, 13 studies met the eligibility criteria and were included in the present work. Seven studies assessed the relationship between vitamin D and TMDs, reporting that vitamin D serum levels are lower in patients with TMDs. Our results suggested that vitamin D receptor (VDR) polymorphisms might have a role in TMDs' development. However, the quality assessed underlined that only one study did not present a serious risk of bias. Further good-quality studies are needed to clarify the linkage between vitamin D deficiency and TMDs, but the evidence currently available has suggested potential correlations.

Vitamin D status in chimpanzees in human care: a Europe wide study

While vitamin D deficiency is a public health concern in humans, comparatively little is known about vitamin D levels in non-human primates. Vitamin D plays a crucial role in overall health and its deficiency is associated with a range of disorders, including cardiovascular disease, which is a leading cause of death in great apes. Serum samples (n = 245) from chimpanzees (Pan troglodytes) housed at 32 European zoos were measured for 25-hydroxyvitamin D2, 25-hydroxyvitamin D3 and total 25-hydroxyvitamin D (25-OHD) using liquid chromatography and tandem mass spectrometry. Of these samples, 33.1% indicated inadequate vitamin D status, using the human reference interval (25-OHD < 50 nmol/L). The season of the year, health status of the animal, and the provision of daily outdoor access had a significant effect on vitamin D status. This is the first large-scale study on vitamin D status of non-human great apes in human care. Inadequate 25-OHD serum concentrations are widespread in the chimpanzee population in Europe and could be a risk factor for the development of idiopathic myocardial fibrosis, a major cause of mortality in this species, as well as other diseases. A review of husbandry and nutrition practices is recommended to ensure optimal vitamin D supply for these endangered animals.

Association between bruxism severity and serum concentrations of 25-hydroxyvitamin D levels

Objectives

The aim of this study was to investigate the possible relationship between bruxism and blood levels of 25‐hydroxyvitamin D.

Material and Methods

One hundred male and female patients from Damascus joined the study. Their ages were in the range of 18–40 years. Two groups were considered in this study, the first group included patients who were already suffering from bruxism (76 patients) and the second group consisted of patients who were not suffering from any bruxism (24 patients). The analysis of the blood samples for 25‐hydroxyvitamin D levels of the two groups was carried out.

Results

The recorded results showed that there is a relationship between the levels of bruxism and 25‐hydroxyvitamin D concentration in the blood (p < .05), enhancing that the bruxism activity has been shown the associated deficiency in 25‐hydroxyvitamin D levels, which can be divided into five different categories.

Conclusions

Within the limitations of this study in spite of the number of patients (one hundred), according to the reported study, it appears that there is a significant relationship between bruxism and the level of 25‐hydroxyvitamin D in the blood.

Vitamin D and Temporomandibular Disorders: What Do We Know So Far?

Background and aims. Vitamin D is synthesized in the skin with the aid of ultraviolet-B radiation, playing a variety of roles in the body. Temporomandibular disorders (TMDs) are a group of pathological conditions involving the temporomandibular joints as well as the masticatory muscles and othersurrounding tissues. In the present narrative review, we investigated the potential role of vitamin D in the etiology of temporomandibular disorders in order todetermine whether the current knowledge supports 25-hidroxyvitamin D (25-OHD) supplementation in temporomandibular disorders associated with insufficient or deficient levels of vitamin D. Methods. A literature research was performed in PubMed, Scopus, Science Direct, and Google Scholar databases, and a total of 10 articles were included for analysis. Results.Among the observational studies published to date, investigating the role for vitamin D in the etiology of TMDs, six of them suggest that there is a connection between the two aspects. In this context, patients suffering from TMD, with deficient levels of vitamin D (<30 ng/mL), are most likely to benefit from supplementation, whereas individuals with vitamin D level >50ng/mL probably have little benefit from supplementation.Conclusion.Vitamin D might be a safe, simple, and potentially beneficial way to prevent TMDs or to reduce pain; however, more randomized and placebo-controlled trials are required before any firm conclusions can be drawn.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Effect of one-anastomosis gastric bypass on cardiovascular risk factors in patients with vitamin D deficiency and morbid obesity: A secondary analysis

BACKGROUND AND AIMS

Bariatric patients often suffer from vitamin D (VD) deficiency, and both, morbid obesity and VD deficiency, are related to an adverse effect on cardiovascular disease (CVD) risk. Therefore, we assessed the change of known CVD risk factors and its associations during the first 12 months following one-anastomosis gastric bypass (OAGB).

METHODS AND RESULTS

In this secondary analysis, CVD risk factors, medical history and anthropometric data were assessed in fifty VD deficient (25-hydroxy-vitamin D (25(OH)D) <75 nmol/l) patients, recruited for a randomized controlled trial of VD supplementation. Based on previous results regarding bone-mass loss and the association between VD and CVD risk, the study population was divided into patients with 25(OH)D ≥50 nmol/l (adequate VD group; AVD) and into those <50 nmol/l (inadequate VD group; IVD) at 6 and 12 months (T6/12) postoperatively. In the whole cohort, substantial remission rates for hypertension (38%), diabetes (30%), and dyslipidaemia (41%) and a significant reduction in CVD risk factors were observed at T12. Changes of insulin resistance markers were associated with changes of total body fat mass (TBF%), 25(OH)D, and ferritin. Moreover, significant differences in insulin resistance markers between AVD and IVD became evident at T12.

CONCLUSION

These findings show that OAGB leads to a significant reduction in CVD risk factors and amelioration of insulin resistance markers, which might be connected to reduced TBF%, change in 25(OH)D and ferritin levels, as an indicator for subclinical inflammation, and an adequate VD status. REGISTERED AT CLINICALTRIALS.GOV: (Identifier: NCT02092376) and EudraCT (Identifier: 2013-003546-16).

Widespread vitamin D deficiency and its sex-specific association with adiposity in Chinese children and adolescents

OBJECTIVES

Vitamin D is involved in various physiologic and pathologic processes in the human body. The aim of this study was to determine the prevalence of vitamin D deficiency and the association of adiposity indicators with 25-hydroxyvitamin D (25[OH]D) in Chinese children and adolescents.

METHODS

This was a population-based, nationwide, multicenter cross-sectional study involving 10 696 participants (51.2% boys) 6 to 18 y of age. Total body fat mass was assessed by dual-energy x-ray absorptiometry, and measures of body mass index (BMI), fat mass index (FMI), fat mass percentage (FMP), and plasma 25(OH)D concentrations were obtained.

RESULTS

The adjusted mean of 25(OH)D was 39.3 nmol/L for all participants, 40.7 nmol/L for boys, and 37.9 nmol/L for girls. Of the children, 30% had vitamin D deficiency (25[OH]D <30 nmol/L) and 80% had vitamin D insufficiency (25[OH]D <50 nmol/L). The prevalence rates of vitamin D deficiency and insufficiency were higher in girls (31%, 83.4%, respectively) than in boys (22.8%, 78.7%, respectively). An L-shape relationship between age and 25(OH)D was observed in all children, with a threshold age of 14 y. Also, there was an inverted U-shaped association of BMI with 25(OH)D, and multivariable linear models shown FMI and FMP were inversely associated with 25(OH)D concentrations, particularly in boys (β = -0.86 and -0.83, respectively, all P < 0.05).

CONCLUSIONS

Vitamin D deficiency was widespread and its sex-specific association with an excess of body fat in Chinese children and adolescents. The findings indicate that targeted screening and treatment guidelines may be useful.

A New Light on Vitamin D in Obesity: A Novel Association with Trimethylamine-N-Oxide (TMAO)

Vitamin D deficiency and obesity are two public health problems extensively exacerbated over the last years. Among the several mechanisms proposed to account for the complex interplay between vitamin D and obesity, one that has gained particular attention is related to the emerging role of obesity-related changes in gut microbiota and gut-derived metabolites, such as Trimethylamine-N-oxide (TMAO). Vitamin D deficiency and high circulating TMAO levels are associated with body weight and the severity of non-alcoholic fatty liver disease (NAFLD). Considering the link of obesity with vitamin D on the one hand and obesity with TMAO on the other hand, and the central role of the liver in both the vitamin D and TMAO metabolism, the aim of this cross-sectional observational study was first, to confirm the possible inverse association between vitamin D and TMAO across different body mass index (BMI) classes and second, to investigate if this association could be influenced by the presence of NAFLD. One hundred and four adult subjects (50 males and 54 females; 35.38 ± 7.49 years) were enrolled. The fatty liver index (FLI) was used as a proxy for the diagnosis of NAFLD. Vitamin D deficiency was found in 65 participants (62.5%), while 33 subjects (31.7%) had insufficient levels, and the remaining subjects had sufficient levels of vitamin D. Subjects with both vitamin D deficiency and FLI-NAFLD had the highest TMAO levels (p < 0.001). By stratifying the sample population according to the BMI classes, vitamin D levels decreased significantly along with the increase of plasma TMAO concentrations, with the lowest vitamin D levels and highest TMAO, respectively, in class III obesity. Vitamin D levels showed significant opposite associations with circulating levels of TMAO (r = −0.588, p < 0.001), but this association was no longer significant after the adjustment for FLI values. The highest values of TMAO were significantly associated with the severity of obesity (OR 7.92; p < 0.001), deficiency of vitamin D (OR 1.62; p < 0.001), and FLI-NAFLD (OR 3.79; p < 0.001). The most sensitive and specific cut-off for vitamin D to predict the circulating levels of TMAO was ≤19.83 ng/mL (p < 0.001). In conclusion, our study suggests that high TMAO levels are associated with vitamin D deficiency and NAFLD. Further studies are required to investigate if there is a causality link or whether all of them are simply the consequence of obesity.

Continued Interest and Controversy: Vitamin D in HIV

PURPOSE OF REVIEW

Vitamin D (VitD) deficiency is highly prevalent among HIV-infected individuals. Given the overlapping risk for several chronic disease and immunomodulatory outcomes from both long-standing HIV and VitD deficiency, there is great interest in clarifying the clinical role of VitD for this population.

RECENT FINDINGS

Recent studies have expanded our knowledge regarding the epidemiology and mechanisms of VitD deficiency-associated outcomes in the setting of HIV. Clinical trials focusing on VitD supplementation have demonstrated a positive impact on bone mineral density in subgroups of HIV-infected individuals initiating ART or on suppressive ART regimens; however, significant heterogeneity exists between studies and data are less consistent with other clinical outcomes. Further research is needed to clarify uncertainly in several domains, including identifying patients at greatest risk for poor outcomes from VitD deficiency, standardizing definitions and measurement techniques, and better quantifying the benefits and risks of VitD supplementation across different demographic strata for skeletal and extra-skeletal outcomes.

Are certain factors involved in calcium metabolism associated with temporomandibular disorders?

Objective: The aim of the present study was to investigate whether there is an association between serum concentrations of calcium, phosphate, alkaline phosphatase, parathyroid hormone (PTH), and vitamin D and temporomandibular disorders (TMDs).Methods: In this case-control study, 51 patients with TMDs (28 patients with TMJ clicking, 5 patients with muscular disorders, and 18 osteoarthritis patients) and 29 healthy subjects within the age range of 20-50 years as the control group, were referred to the laboratory for calcium, phosphate, alkaline phosphatase, PTH, and vitamin D (25 OHD) analysis tests. The TMJ status of all participants was examined according to RDC-TMD criteria by a prosthodontist who is an expert in TMDs. The results were analyzed with Fisher's precise test.Results: No statistically significant difference was observed between TMD patients and healthy subjects.Conclusion: Serum concentrations of calcium, phosphate, alkaline phosphatase, PTH, and vitamin D are not associated with TMDs.

Sex, Residence and Fish Intake Predict Vitamin D Status in Chinese Centenarians

OBJECTIVES

This study aims to investigate the prevalence of vitamin D deficiency in Chinese centenarians and to identify the factors associated with vitamin D deficiency.

DESIGN

Cross-sectional population-based study.

SETTING

Hainan province in the south of China.

PARTICIPANTS

943 subjects aged 100 years old and older.

METHODS

Details on sociodemographics and lifestyle characteristics were collected using a structured questionnaire. Anthropometrics and blood samples were obtained. Vitamin D deficiency was defined as serum 25-hydroxyvitamin D concentration < 20ng/mL (50nmol/L).

RESULTS

The overall prevalence of vitamin D deficiency among these 943 centenarians was 39.9% (376 subjects) and the mean serum vitamin D concentrations were 22.7±9.5 (ng/mL). Female centenarians had higher prevalence of vitamin D deficiency than male (44.0% vs. 21.7%, P <0.001). Multivariate logistic regression analyses showed that being female, urban residency, lower body mass index, higher serum parathyroid hormone levels, no fish consumption, and less sun exposure time were all significant and independent determinants of vitamin D deficiency. No significant associations of vitamin D deficiency with ethnic, education, geographic location, tea drinking, alcohol use, or smoking were found in this study.

CONCLUSION

Vitamin D deficiency was common in Chinese centenarians, especially in women. Given that vitamin D deficiency is linked to numerous adverse health outcomes, dietary, outdoor activities and other intervention measures are needed to correct vitamin D deficiency in this population.

Rationale and Plan for Vitamin D Food Fortification: A Review and Guidance Paper

Vitamin D deficiency can lead to musculoskeletal diseases such as rickets and osteomalacia, but vitamin D supplementation may also prevent extraskeletal diseases such as respiratory tract infections, asthma exacerbations, pregnancy complications and premature deaths. Vitamin D has a unique metabolism as it is mainly obtained through synthesis in the skin under the influence of sunlight (i.e., ultraviolet-B radiation) whereas intake by nutrition traditionally plays a relatively minor role. Dietary guidelines for vitamin D are based on a consensus that serum 25-hydroxyvitamin D (25[OH]D) concentrations are used to assess vitamin D status, with the recommended target concentrations ranging from ≥25 to ≥50 nmol/L (≥10-≥20 ng/mL), corresponding to a daily vitamin D intake of 10 to 20 μg (400-800 international units). Most populations fail to meet these recommended dietary vitamin D requirements. In Europe, 25(OH)D concentrations <30 nmol/L (12 ng/mL) and <50 nmol/L (20 ng/mL) are present in 13.0 and 40.4% of the general population, respectively. This substantial gap between officially recommended dietary reference intakes for vitamin D and the high prevalence of vitamin D deficiency in the general population requires action from health authorities. Promotion of a healthier lifestyle with more outdoor activities and optimal nutrition are definitely warranted but will not erase vitamin D deficiency and must, in the case of sunlight exposure, be well balanced with regard to potential adverse effects such as skin cancer. Intake of vitamin D supplements is limited by relatively poor adherence (in particular in individuals with low-socioeconomic status) and potential for overdosing. Systematic vitamin D food fortification is, however, an effective approach to improve vitamin D status in the general population, and this has already been introduced by countries such as the US, Canada, India, and Finland. Recent advances in our knowledge on the safety of vitamin D treatment, the dose-response relationship of vitamin D intake and 25(OH)D levels, as well as data on the effectiveness of vitamin D fortification in countries such as Finland provide a solid basis to introduce and modify vitamin D food fortification in order to improve public health with this likewise cost-effective approach.

The Role of Toll-Like Receptors and Vitamin D in Cardiovascular Diseases-A Review

Cardiovascular diseases are the leading cause of mortality worldwide. Therefore, a better understanding of their pathomechanisms and the subsequent implementation of optimal prophylactic and therapeutic strategies are of utmost importance. A growing body of evidence states that low-grade inflammation is a common feature for most of the cardiovascular diseases in which the contributing factors are the activation of toll-like receptors (TLRs) and vitamin D deficiency. In this article, available data concerning the association of cardiovascular diseases with TLRs and vitamin D status are reviewed, followed by a discussion of new possible approaches to cardiovascular disease management.