The Vitamin D Assessment (ViDA) study - Design and main findings

The Lebanese GRADE-based vitamin D guidelines: a paradigm for the MENA region

BACKGROUND

The Middle East and North Africa region are traditionally known as regions with a high prevalence of vitamin D deficiency. However, serum 25-hydroxyvitamin D (25OHD) levels seem to be increasing lately. We developed guidelines on the screening and supplementation of adult Lebanese patients with vitamin D. These guidelines address community-dwelling and institutionalized individuals.

METHODS

Our guideline panel consisted of clinical and methodology experts that formulated the guidelines questions. We conducted a systematic review to gather global data on fracture (CRD42019129540), regional data on vitamin D trials (CRD42014010488), and on patients' values and preferences (CRD42022320022). We also complemented the latter with results from a cross-sectional local study. We followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology to assess the quality and certainty of evidence, and to develop recommendations.

RESULTS

For community-dwelling and institutionalized Lebanese adult population, the panel suggests no screening for vitamin D deficiency, over screening for vitamin D deficiency (conditional recommendation, based on very low certainty evidence). For community-dwelling Lebanese adult population, the panel suggests no supplementation with calcium and vitamin D, over supplementation (conditional recommendation, based on moderate certainty evidence). For institutionalized Lebanese adult population, the panel suggests supplementation with calcium and vitamin D, over no supplementation (conditional recommendation, based on moderate certainty evidence). The guidelines also identify high-risk subgroups, more likely to benefit from screening and supplementation. In community dwelling and institutionalized Lebanese adult individuals, for whom there is a decision to supplement with calcium and vitamin D, the panel suggests supplementation with a daily vitamin D equivalent of 600-2000 IU, as compared to doses higher than 2000 IU (conditional recommendation, very low certainty evidence).

CONCLUSION

The Lebanese GRADE-based vitamin D guidelines recommend against population screening and vitamin D supplementation. Subgroups at high risk are identified. The guidelines take into account contextual factors, and allow their adoption or adaptation in countries in the region.

Prevention and Treatment of Vitamin D Deficiency in India: An Expert Group Consensus

Vitamin D deficiency is highly prevalent in India, yet no standardized guidelines exist for classifying vitamin D status or its prevention and treatment. Even more, there is no consensus specific to vitamin D supplementation for the Indian population, and there are inconsistencies in the cut-off values for deficiency, severe deficiency, and insufficiency across various guidelines, which this evidence-based consensus seeks to resolve, thus guiding healthcare professionals in identifying, preventing, and managing vitamin D deficiency. An expert group of 41 endocrinologists from across India developed the consensus using the DELPHI method, achieving over 90% agreement on all recommendations. The consensus defines vitamin D deficiency, severe deficiency, and insufficiency, recommending supplementation strategies to maintain physiological 25(OH) D levels of 40-60 ng/mL (100-150 nmol/L). Tailored treatment regimens for neonates, infants, children, adolescents, adults, the elderly, pregnant and lactating women, and individuals with co-morbid conditions are provided to ensure optimal health for all age groups in India.

A Personalized Approach to Vitamin D Supplementation in Cardiovascular Health Beyond the Bone: An Expert Consensus by the Italian National Institute for Cardiovascular Research

Vitamin D is increasingly recognized for its role in cardiovascular health beyond its well-established effects on bone metabolism. This review synthesizes findings from observational studies, interventional trials, and meta-analyses to clarify the mechanisms through which vitamin D impacts cardiovascular health, including its influence on vascular function, inflammation, and metabolic pathways. Additionally, this review emphasizes the importance of a personalized approach to vitamin D supplementation, integrating individual cardiovascular risk profiles, baseline vitamin D levels, and comorbid conditions, such as hypertension and diabetes. While current evidence supports the association between low vitamin D levels and increased cardiovascular mortality, this work contributes novel insights by proposing tailored strategies for supplementation, particularly for high-risk subgroups. Practical recommendations for implementing these strategies in clinical practice are also discussed, providing a framework for optimizing cardiovascular outcomes through individualized vitamin D management.

The essential role of combined calcium and vitamin D supplementation in the osteoporosis scenario in italy: Expert opinion paper

An Italian multidisciplinary working group discussed the current Italian scenario of osteoporosis management during a meeting and highlighted the essential role of calcium and vitamin D supplementation in the prevention of fragility fractures.

PURPOSE

This paper aims to review and discuss data on calcium and vitamin D requirements and the role of combined calcium and vitamin D supplementation in the treatment of patients with osteoporosis.

METHODS

The discussion of the experts covered literature data on calcium and vitamin D supplementation, gaps in the diagnosis and treatment of osteoporosis, and the role of the primary care physician in identifying and treating patients with osteoporosis. Articles for consideration were identified through PubMed searches using different combinations of pertinent keywords.

RESULTS

The discussion highlighted that insufficient calcium or vitamin D intake increases the risk of fragility fractures. The experts also drew attention to the essential role of calcium and vitamin D supplementation in achieving an anti-fracture effect and supporting the efficacy of anti-osteoporotic agents without increasing nephrolithiasis and cardiovascular risks. In addition, the discussion underlined the role of the primary care physician in the initial clinical approach to patients with osteoporosis.

CONCLUSIONS

The experts believe that efficient treatment for patients with osteoporosis should include calcium and vitamin D supplementation to achieve adequate levels that are able to inhibit the parathyroid hormone and bone resorption.

Vitamin D3 reduces the expression of M1 and M2 macrophage markers in breast cancer patients

Vitamin D3 (VD) is known for its immunomodulatory and anticancer effects. This study aimed to characterize tumor-associated macrophages (TAMs) in breast cancer (BC) and assess the influence of VD and its active metabolite, calcitriol, on their polarization. TAMs were isolated from BC patients and characterized. Monocytes were differentiated into macrophage classes (M0, M1, M2a, M2c) and treated ex vivo with calcitriol. The expression of VD-related proteins in tumor tissue was correlated with TAMs and monocyte-derived macrophages (MDMs) characteristics. TAM expression of CD200R, CD204, CD80, HLA-DR, and CD44 was negatively correlated with CYP27B1 in selected patient groups. Patients with high CYP27B1 tumor expression showed significantly lower CD200R, CD204, and CD44 expression. In patients with normal VD levels and premenopausal, CD80 expression in M2a and M2c MDMs (control, untreated ex vivo with calcitriol) was negatively correlated with plasma VD. Calcitriol reduced HLA-DR during MDM differentiation in all patients; CD80 decrease significantly except in patients with normal VD levels or metastasis. Calcitriol also decreased CD163 expression. The decrease in both M1 and M2 macrophage markers by calcitriol or their negative correlation with CYP27B1 indicate the modulatory, but rather anticancer activity of VD. The intensity of these effects was the strongest in postmenopausal patients and those without metastases.

The complex relationship between vitamin D and kidney stones: balance, risks, and prevention strategies

The association between vitamin D and kidney stones is characterized by a remarkable multi-dimensional complexity involving numerous physiological and metabolic pathways. Vitamin D is pivotal in maintaining calcium-phosphorus metabolic homeostasis and bone health. However, fluctuations in its intake, whether excessive or insufficient, May potentially increase the risk of kidney stones. Vitamin D exerts its influence on kidney stone formation indirectly by increasing the efficiency of intestinal calcium absorption and regulating renal calcium excretion. Moreover, there is a robust correlation between various states of vitamin D, particularly its active form, 1,25-dihydroxyvitamin D, and the development of numerous kidney stones. This finding underscores the necessity of individualized medical treatment in vitamin D supplementation and kidney stone prevention. When developing treatment strategies, it is essential to consider the patient's genetic background, lifestyle, environmental factors, and overall health. To prevent the formation of kidney stones, it is recommended that patients adopt a comprehensive approach, which May include measures such as moderate sun exposure, dietary modification, moderate exercise, and weight management. These preventive measures are designed to maintain healthy calcium and phosphorus metabolism and reduce kidney stone formation risk. Future studies should aim to elucidate the detailed mechanisms of vitamin D metabolism, individual differences, and the role of genes in this process. Furthermore, the role of lifestyle interventions in preventing kidney stones requires greater attention. Moreover, the implementation of large-scale, long-term prospective studies and randomized controlled trials will facilitate the assessment of the actual effects of diverse vitamin D supplementation strategies, thereby providing a robust scientific foundation for advancing more precise prevention strategies and clinical guidelines.

Consensus Statement on Vitamin D Status Assessment and Supplementation: Whys, Whens, and Hows

The 6th International Conference, "Controversies in Vitamin D," was convened to discuss controversial topics, such as vitamin D metabolism, assessment, actions, and supplementation. Novel insights into vitamin D mechanisms of action suggest links with conditions that do not depend only on reduced solar exposure or diet intake and that can be detected with distinctive noncanonical vitamin D metabolites. Optimal 25-hydroxyvitamin D (25(OH)D) levels remain debated. Varying recommendations from different societies arise from evaluating different clinical or public health approaches. The lack of assay standardization also poses challenges in interpreting data from available studies, hindering rational data pooling and meta-analyses. Beyond the well-known skeletal features, interest in vitamin D's extraskeletal effects has led to clinical trials on cancer, cardiovascular risk, respiratory effects, autoimmune diseases, diabetes, and mortality. The initial negative results are likely due to enrollment of vitamin D-replete individuals. Subsequent post hoc analyses have suggested, nevertheless, potential benefits in reducing cancer incidence, autoimmune diseases, cardiovascular events, and diabetes. Oral administration of vitamin D is the preferred route. Parenteral administration is reserved for specific clinical situations. Cholecalciferol is favored due to safety and minimal monitoring requirements. Calcifediol may be used in certain conditions, while calcitriol should be limited to specific disorders in which the active metabolite is not readily produced in vivo. Further studies are needed to investigate vitamin D effects in relation to the different recommended 25(OH)D levels and the efficacy of the different supplementary formulations in achieving biochemical and clinical outcomes within the multifaced skeletal and extraskeletal potential effects of vitamin D.

High-dose vitamin D3 supplementation shows no beneficial effects on white blood cell counts, acute phase reactants, or frequency of respiratory infections

BACKGROUND

Vitamin D has been suggested to influence the immune system, and vitamin D metabolites and the vitamin D receptor (VDR) are generated and expressed in white blood cells (WBC). Moreover, vitamin D status has been associated with incidence and prognosis of some respiratory tract infections (RTI). Therefore, we investigated the effect of vitamin D3 supplementation on WBC, acute phase reactants (APR), and the risk of developing RTIs.

METHODS

A double-blinded, randomized, placebo-controlled clinical trial of 307 infertile men with multiple secondary immunological endpoints. The vitamin D3 group (n = 151) initially received 300,000 IU (7,500 µg) cholecalciferol once - followed by 1,400 IU (35 µg) daily for 150 days. The placebo group (n = 156) did not receive active ingredients.

RESULTS

At baseline, stratification into clinically relevant groups of vitamin D status (< 25; 25-50; 50-75; >75 nmol/L), showed an inverse association with total leucocyte concentrations (7.0 vs. 6.0 vs. 6.0 vs. 5.5 (109/L); p = 0.007), lymphocytes (2.4 vs. 2.1 vs. 2.0 vs. 2.0 (109/L); p = 0.048), CRP (2.0 vs. 1.7 vs. 1.2 vs. 1.2 (mg/L); p = 0.037), and orosomucoid (0.82 vs. 0.77 vs. 0.76 vs. 0.70 (g/L); p = 0.015). After 150 days, no differences were detected in WBC counts or APRs between the vitamin D3 and the placebo group. However, vitamin D3 treated men had a higher prevalence of self-reported RTIs compared with the placebo group (55% vs. 39%; p = 0.005).

CONCLUSIONS

High-dose vitamin D3 supplementation did not alter WBCs or APRs, but a higher prevalence of respiratory infections was observed in the vitamin D3 group. Serum 25(OH)D3 was negatively correlated with most WBCs, indicating that vitamin D status may be linked with inflammation and WBC turnover, but not an important determinant of developing RTIs.

TRIAL REGISTRATION

NCT01304927 (ClinicalTrials.gov). Registered February 20, 2011.

Supplementing Vitamin D in Different Patient Groups to Reduce Deficiency

INTRODUCTION

Studies indicate a high prevalence of vitamin D deficiency in both the general population and at-risk groups. Given the association between vitamin D deficiency and various diseases, addressing this concern becomes crucial, especially in situations where routine monitoring is challenging.

MATERIALS AND METHODS

A systematic literature review of the current knowledge on vitamin D dosing in diverse at-risk populations and the application of the findings to a broader clinical perspective.

RESULTS

The reviewed studies revealed a high prevalence of vitamin D deficiency among patients with musculoskeletal disorders, systemic connective tissue diseases, corticosteroid use, endocrine and metabolic conditions, malabsorption syndromes, obesity, chronic kidney disease, cancer, and central nervous system diseases. Vitamin D deficiency was often more severe compared to the general population. Higher dosages of vitamin D beyond the recommended levels for the general population were shown to be effective in improving vitamin D status in these at-risk individuals. Additionally, some studies suggested a potential link between intermittent vitamin D administration and improved adherence.

CONCLUSION

Simplified dosing could empower clinicians to address vitamin D deficiency, particularly in high-risk populations, even without routine monitoring. Further research is needed to establish the optimal dosing regimens for specific at-risk populations.

Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate

Following two requests from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for vitamin D and to propose a conversion factor (CF) for calcidiol monohydrate into vitamin D3 for labelling purposes. Vitamin D refers to ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), and calcidiol monohydrate. Systematic reviews of the literature were conducted to assess the relative bioavailability of calcidiol monohydrate versus vitamin D3 on serum 25(OH)D concentrations, and for priority adverse health effects of excess vitamin D intake, namely persistent hypercalcaemia/hypercalciuria and endpoints related to musculoskeletal health (i.e. falls, bone fractures, bone mass/density and indices thereof). Based on the available evidence, the Panel proposes a CF for calcidiol monohydrates of 2.5 for labelling purposes. Persistent hypercalciuria, which may be an earlier sign of excess vitamin D than persistent hypercalcaemia, is selected as the critical endpoint on which to base the UL for vitamin D. A lowest-observed-adverse-effect-level (LOAEL) of 250 μg/day is identified from two randomised controlled trials in humans, to which an uncertainty factor of 2.5 is applied to account for the absence of a no-observed-adverse-effect-level (NOAEL). A UL of 100 μg vitamin D equivalents (VDE)/day is established for adults (including pregnant and lactating women) and for adolescents aged 11-17 years, as there is no reason to believe that adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults. For children aged 1-10 years, a UL of 50 μg VDE/day is established by considering their smaller body size. Based on available intake data, European populations are unlikely to exceed the UL, except for regular users of food supplements containing high doses of vitamin D.

The Role of Vitamin D in Health and Disease: A Narrative Review on the Mechanisms Linking Vitamin D with Disease and the Effects of Supplementation

Vitamin D insufficiency or deficiency (VDD) is a very prevalent condition in the general population. Vitamin D is necessary for optimal bone mineralization, but apart from the bone effects, preclinical and observational studies have suggested that vitamin D may have pleiotropic actions, whereas VDD has been linked to several diseases and higher all-cause mortality. Thus, supplementing vitamin D has been considered a safe and inexpensive approach to generate better health outcomes-and especially so in frail populations. Whereas it is generally accepted that prescribing of vitamin D in VDD subjects has demonstrable health benefits, most randomized clinical trials, although with design constraints, assessing the effects of vitamin D supplementation on a variety of diseases have failed to demonstrate any positive effects of vitamin D supplementation. In this narrative review, we first describe mechanisms through which vitamin D may exert an important role in the pathophysiology of the discussed disorder, and then provide studies that have addressed the impact of VDD and of vitamin D supplementation on each disorder, focusing especially on randomized clinical trials and meta-analyses. Despite there already being vast literature on the pleiotropic actions of vitamin D, future research approaches that consider and circumvent the inherent difficulties in studying the effects of vitamin D supplementation on health outcomes are needed to assess the potential beneficial effects of vitamin D. The evaluation of the whole vitamin D endocrine system, rather than only of 25-hydroxyvitamin D levels before and after treatment, use of adequate and physiologic vitamin D dosing, grouping based on the achieved vitamin D levels rather than the amount of vitamin D supplementation subjects may receive, and sufficiently long follow-up are some of the aspects that need to be carefully considered in future studies.

Vitamin D in the older population: a consensus statement

BACKGROUND

This paper reports results from the 5th International Conference "Controversies in Vitamin D" that was held in Stresa, Italy, 15-18 September 2021. The conference is part of this series that started in 2017 and has been conducted annually since. The objective of these conferences is to identify timely and controversial topics related to Vitamin D. Dissemination of the results of the conference through publications in peer-reviewed journals is an important means by which the most up to date information can be shared with physicians, investigators, and other health care professionals. Vitamin D and aging, the subject of this paper was featured at the conference.

METHODS

Participants were selected to review available literature on assigned topics related to vitamin D and aging and to present their findings with illustrative material, the intent of which was to stimulate discussion and to arrive at a consensus. The presentations were directed towards the following areas: impact of aging on vitamin D production and levels; skeletal effects of vitamin D deficiency in the older population; falls and vitamin D in the aging; potential extra skeletal effects of vitamin D; and strategies to prevent vitamin D deficiency. A final topic was related to how vitamin D might influence the efficacy of vaccines for Covid-19.

RESULTS

Hypovitaminosis D can lead to several skeletal and extra-skeletal outcomes. Older adults are at risk for vitamin D deficiency as both production and metabolism of vitamin D change with aging due to factors, such as reduced sun exposure and reduced production capacity of the skin. Skeletal consequences of these age-related changes can include reduced bone mineral density, osteomalacia and fractures. Potential extra-skeletal effects can include added risks for falls, reduced muscle strength, diabetes, cancer, and cardiovascular disease. Strategies to avoid these vitamin D deficiency-related negative outcomes include sun exposure, food fortification, and supplementation. While aging does not diminish sufficient reserve capacity for cutaneous vitamin D production, concerns about skin cancers and practical matters for the institutionalized elderly limit this option. Supplementation with vitamin D is the best option either pharmacologically or through food fortification. Regardless of treatment strategies, interventions to restore sufficient vitamin D status will show positive results only in those who are truly deficient. Thus, treatment goals should focus on avoiding 25(OH)D serum levels <30 nmol/l, with a goal to reach levels >50 nmol/l.

CONCLUSIONS

The results of this conference has led to consensus on several issues. Vitamin D supplementation should be combined with calcium to reduce fractures in the older population. The goal for adequate Vitamin D status should be to reach a serum level of 25(OH)D >50 nmol/l. It appears that daily low-dose vitamin D regimens reduce the risk of falling, especially in the elderly, compared with infrequent, large bolus doses that may increase it. The role of Vitamin D supplementation on muscle strength remains to be clarified. On the other hand, supplementation decreases the risk of progression to T2D from prediabetes among those who are Vitamin Ddeficient. Of three possible strategies to establish vitamin D sufficiency - sunshine exposure, food fortification, and supplementation - the latter seems to be the most effective and practical in the aging population.

Effect of supplemental vitamin D3 on bone mineral density: a systematic review and meta-analysis

Context

There is still controversy over the effect of vitamin D3 supplementation on bone health.

Objective

The effects of vitamin D3 supplementation on bone mineral density (BMD) and markers of bone turnover, as well as the dose-response relationship between vitamin D3 and bone health in adults, were evaluated.

Data Sources

The PubMed, Scopus, Cochrane, Web of Science, and AGRIS databases were searched for articles published through April 30, 2022. Thirty-nine of the 6409 records identified met the inclusion criteria

Data Extraction

Data were extracted from articles by 2 authors, and data extraction was cross-checked independently. A random-effects model was used to estimate the pooled effect size and the associated 95%CI for the effect of vitamin D3 for each outcome. A one-stage random-effects dose-response model was used to estimate the dose-response relationship between vitamin D3 supplementation and BMD.

Data Analysis

Results of meta-analysis showed a beneficial effect of vitamin D3 at the lumbar spine (standardized mean difference [SMD] = 0.06; 95%CI, 0.01–0.12) and femoral neck (SMD = 0.25; 95%CI, 0.09–0.41). Dose-response analysis revealed a linear relationship between vitamin D3 supplementation doses and BMD at the femoral neck, lumbar spine, and total hip sites. No significant effect of vitamin D3 supplementation on whole-body or total hip BMD was observed (P &gt; 0.05). Vitamin D3 supplementation significantly decreased BMD at both proximal and distal forearm (SMD = −0.16; 95%CI, −0.26 to −0.06). The variables of ethnicity, age, baseline 25-hydroxyvitamin D (25[OH]D), menopause status, vitamin D3 dosing frequency, and bone health status (P interaction = 0.02) altered the effect of vitamin D3 supplementation on BMD. Additionally, a nonlinear relationship between vitamin D3 supplement doses and markers of bone turnover was found.

Conclusion

A protective effect of vitamin D3 supplementation on BMD of the lumbar spine, femoral neck, and total hip is implicated.

Systematic Review Registration

PROSPERO registration number CRD42017054132.

Factors associated with self-reported sun exposure in a multi-ethnic community sample from New Zealand

Sun exposure, the main source of vitamin D, may have beneficial effects in humans, including for cardiovascular health. However, little is known about the characteristics related to sun exposure. Previous studies have surveyed participants with a demographic profile that is restricted by sex and ethnicity. We carried out an analysis to identify factors associated with self-reported sun exposure in a large multi-ethnic study of men and women. The study was a cross-sectional analysis of baseline data collected in a large vitamin D supplementation randomized controlled trial. The weekly amount of sun exposure in the past three months was assessed using a questionnaire. Multivariable prevalence ratios (PR) of high sun exposure (≥ 15 h/ week) associated with demographic and lifestyle variables were calculated using Poisson regression to adjust for covariates. A P-value of < 0.05 (2-tail) was used to determine statistical significance. A total of 5039 participants aged 50-84 years were analysed, who comprised 330 Pacific Islanders, 267 Māori, 242 South Asian and 4200 Other ethnicities (mostly European ancestry). For demographic variables, high sun exposure was associated with sex (higher in males), ethnicity (highest in Māori, lowest in South Asian), and education (highest in those completing secondary level education), but was lowest in the oldest age-group (80-84 years). For lifestyle variables, high sun exposure was associated with higher levels of alcohol drinking, TV watching and physical activity, but was not associated with tobacco smoking. Weekly sun exposure was lower in participants who were overweight or obese (compared to those with normal body mass index), and in those who reported a skin reaction to sun exposure of burning only (compared to those who reported tanning). These associations remained when all variables were included in the same model. In conclusion, several demographic and lifestyle factors were associated independently with the sun exposure, the primary source of vitamin D. Understanding how these factors are associated with sun exposure may refine strategies to minimise vitamin D deficiency.

Effects of Perceived Benefit on Vitamin D Supplementation Intention: A Theory of Planned Behaviour Perspective

There are many factors that affect vitamin D supplementation, including those from the theory of planned behaviour (TPB); however, how the perceived benefit acts in the model remains unknown. In the current study, we tested the efficacy of the TPB and the impacts of the perceived benefit (PBE) in the model. The subjects were 287 customers who purchased vitD from pharmacies in major cities in Taiwan. A structured questionnaire was used to collect the data. t-tests, analysis of variance (ANOVA), regression analyses, and path analysis via SPSS and AMOS were used to analyse the data. The original TPB model explained 47.5% of the variance of intention with the three variables of attitude (β = 0.261), perceived behavioural control (β = 0.183), and subjective norms (β = 0.169). The model that incorporated PBE increased the explained variance to 59.7%, and PBE became the strongest predictor (β = 0.310) and a significant mediator linking attitude, subjective norms, perceived control (ANC) with supplementation intention. PBE and attitude were the two most important variables in predicting vitD supplementation intention. We suggest that updated information regarding dietary sources of vitD and its benefits should be included in health- or nutrition-related courses in education programs for the overall health of the nation.

Critical Appraisal of Large Vitamin D Randomized Controlled Trials

As a consequence of epidemiological studies showing significant associations of vitamin D deficiency with a variety of adverse extra-skeletal clinical outcomes including cardiovascular diseases, cancer, and mortality, large vitamin D randomized controlled trials (RCTs) have been designed and conducted over the last few years. The vast majority of these trials did not restrict their study populations to individuals with vitamin D deficiency, and some even allowed moderate vitamin D supplementation in the placebo groups. In these RCTs, there were no significant effects on the primary outcomes, including cancer, cardiovascular events, and mortality, but explorative outcome analyses and meta-analyses revealed indications for potential benefits such as reductions in cancer mortality or acute respiratory infections. Importantly, data from RCTs with relatively high doses of vitamin D supplementation did, by the vast majority, not show significant safety issues, except for trials in critically or severely ill patients or in those using very high intermittent vitamin D doses. The recent large vitamin D RCTs did not challenge the beneficial effects of vitamin D regarding rickets and osteomalacia, that therefore continue to provide the scientific basis for nutritional vitamin D guidelines and recommendations. There remains a great need to evaluate the effects of vitamin D treatment in populations with vitamin D deficiency or certain characteristics suggesting a high sensitivity to treatment. Outcomes and limitations of recently published large vitamin D RCTs must inform the design of future vitamin D or nutrition trials that should use more personalized approaches.

Assessment of factors associated with PSA level in prostate cancer cases and controls from three geographical regions

It is being debated whether prostate-specific antigen (PSA)-based screening effectively reduces prostate cancer mortality. Some of the uncertainty could be related to deficiencies in the age-based PSA cut-off thresholds used in screening. Current study considered 2779 men with prostate cancer and 1606 men without a cancer diagnosis, recruited for various studies in New Zealand, US, and Taiwan. Association of PSA with demographic, lifestyle, clinical characteristics (for cases), and the aldo–keto reductase 1C3 (AKR1C3) rs12529 genetic polymorphisms were analysed using multiple linear regression and univariate modelling. Pooled multivariable analysis of cases showed that PSA was significantly associated with demographic, lifestyle, and clinical data with an interaction between ethnicity and age further modifying the association. Pooled multivariable analysis of controls data also showed that demographic and lifestyle are significantly associated with PSA level. Independent case and control analyses indicated that factors associated with PSA were specific for each cohort. Univariate analyses showed a significant age and PSA correlation among all cases and controls except for the US-European cases while genetic stratification in cases showed variability of correlation. Data suggests that unique PSA cut-off thresholds factorized with demographics, lifestyle and genetics may be more appropriate for prostate cancer screening.

Calcium and vitamin D supplementation: when and why

Osteoporosis is a common disease, with fragility fractures representing its dreaded complications. The role of calcium and vitamin D supplementation needs to be addressed in the context of a heavy health burden, with a massive impact on individuals, healthcare systems, and societies as a whole. Calcium and vitamin D are often discussed together as interventions for promoting bone health. Still, it is essential to remember that they are quite distinct entities that play different roles in mineral metabolism. Insufficient calcium intake and vitamin D deficiency are common and widespread. Furthermore, a strong association between vitamin D deficiency and extra-skeletal outcomes has emerged over the last decades. When dietary intake is insufficient, with little room for improvement, several supplementation strategies have proved to be effective and safe. Adequate calcium intake and vitamin D serum levels should be pursued efficiently in the general population, and deficiency should be considered unacceptable in subsets particularly at risk. The aim of this narrative review was to present an overview of calcium and vitamin D intake and their supplementation.

Where are we now? Emerging opportunities and challenges in the management of secondary hyperparathyroidism in patients with non-dialysis chronic kidney disease

Rising levels of parathyroid hormone (PTH) are common in patients with chronic kidney disease (CKD) not on dialysis and are associated with an elevated risk of morbidity (including progression to dialysis) and mortality. However, there are several challenges for the clinical management of secondary hyperparathyroidism (SHPT) in this population. While no recognised target level for PTH currently exists, it is accepted that patients with non-dialysis CKD should receive early and regular monitoring of PTH from CKD stage G3a. However, studies indicate that adherence to monitoring recommendations in non-dialysis CKD may be suboptimal. SHPT is linked to vitamin D [25(OH)D] insufficiency in non-dialysis CKD, and correction of low 25(OH)D levels is a recognised management approach. A second challenge is that target 25(OH)D levels are unclear in this population, with recent evidence suggesting that the level of 25(OH)D above which suppression of PTH progressively diminishes may be considerably higher than that recommended for the general population. Few therapeutic agents are licensed for use in non-dialysis CKD patients with SHPT and optimal management remains controversial. Novel approaches include the development of calcifediol in an extended-release formulation, which has been shown to increase 25(OH)D gradually and provide a physiologically-regulated increase in 1,25(OH)2D that can reliably lower PTH in CKD stage G3-G4 without clinically meaningful increases in serum calcium and phosphate levels. Additional studies would be beneficial to assess the comparative effects of available treatments, and to more clearly elucidate the overall benefits of lowering PTH in non-dialysis CKD, particularly in terms of hard clinical outcomes.

Effect of monthly vitamin D supplementation on antibiotic prescribing in older adults: a post hoc analysis of a randomized controlled trial

BACKGROUND

Observational studies have reported that low vitamin D status is associated with increased risk of antibiotic use. However, trials on the effect of vitamin D supplementation on antibiotics are limited and inconclusive.

OBJECTIVES

The main objective of this study was to determine the effect of monthly vitamin D supplementation on the proportion of adults with ≥1 prescriptions of antibiotics. The secondary outcomes were to determine the effect of monthly vitamin D supplementation on the number of antibiotic prescriptions and the number of days on antibiotics.

METHODS

This was a post hoc analysis of a randomized, double-blinded, placebo-controlled trial with community-based older adults who were randomly assigned to receive monthly 100,000 IU of vitamin D or identical placebo. All analyses were based on the principle of "intention to treat." RR from log-binomial models and the incidence rate ratio (IRR) from negative binomial models were estimated for primary and secondary outcomes after adjusting for age, sex, and ethnicity.

RESULTS

A total of 5108 participants aged 50-84 y were randomly assigned to vitamin D supplementation (n = 2558) or placebo (n = 2550) groups. During a median follow-up of 3.3 y, 4211 (82%) participants were prescribed antibiotics. There was no difference in the proportion of participants prescribed antibiotics between vitamin D (82%) and placebo (83%) groups (adjusted RR: 0.99; 95% CI: 0.97, 1.01; P = 0.42). Similarly, the number of antibiotic prescriptions per person-year did not differ between the 2 treatment groups (adjusted IRR: 0.98; 95% CI: 0.93, 1.04; P = 0.58). However, the number of days on antibiotics per person-year was significantly lower in the vitamin D group (mean ± SEM: 15 ± 0.7) compared with the placebo group (mean ± SEM: 17 ± 0.8) (adjusted IRR: 0.90; 95% CI: 0.82, 0.98; P = 0.01), especially for the tetracyclines (IRR: 0.65; 95% CI: 0.50, 0.85; P = 0.002).

CONCLUSIONS

Long-term, monthly, high-dose vitamin D3 supplementation did not prevent antibiotic prescribing in older adults, but the vitamin D group had fewer days per person-year on antibiotics. Further research is required to replicate these findings. This trial was registered at www.anzctr.org.au as ACTRN12611000402943.

The Role of Nutrition in COVID-19 Susceptibility and Severity of Disease: A Systematic Review

BACKGROUND

Many nutrients have powerful immunomodulatory actions with the potential to alter susceptibility to coronavirus disease 2019 (COVID-19) infection, progression to symptoms, likelihood of severe disease, and survival.

OBJECTIVE

The aim was to review the latest evidence on how malnutrition across all its forms (under- and overnutrition and micronutrient status) may influence both susceptibility to, and progression of, COVID-19.

METHODS

We synthesized information on 13 nutrition-related components and their potential interactions with COVID-19: overweight, obesity, and diabetes; protein-energy malnutrition; anemia; vitamins A, C, D, and E; PUFAs; iron; selenium; zinc; antioxidants; and nutritional support. For each section we provide: 1) a landscape review of pertinent material; 2) a systematic search of the literature in PubMed and EMBASE databases, including a wide range of preprint servers; and 3) a screen of 6 clinical trial registries. All original research was considered, without restriction to study design, and included if it covered: 1) severe acute respiratory syndrome coronavirus (CoV) 2 (SARS-CoV-2), Middle East respiratory syndrome CoV (MERS-CoV), or SARS-CoV viruses and 2) disease susceptibility or 3) disease progression, and 4) the nutritional component of interest. Searches took place between 16 May and 11 August 2020.

RESULTS

Across the 13 searches, 2732 articles from PubMed and EMBASE, 4164 articles from the preprint servers, and 433 trials were returned. In the final narrative synthesis, we include 22 published articles, 38 preprint articles, and 79 trials.

CONCLUSIONS

Currently there is limited evidence that high-dose supplements of micronutrients will either prevent severe disease or speed up recovery. However, results of clinical trials are eagerly awaited. Given the known impacts of all forms of malnutrition on the immune system, public health strategies to reduce micronutrient deficiencies and undernutrition remain of critical importance. Furthermore, there is strong evidence that prevention of obesity and type 2 diabetes will reduce the risk of serious COVID-19 outcomes. This review is registered at PROSPERO as CRD42020186194.

Restoration of Vitamin D Levels Improves Endothelial Function and Increases TASK-Like K+ Currents in Pulmonary Arterial Hypertension Associated with Vitamin D Deficiency

Background: Vitamin D (vitD) deficiency is highly prevalent in patients with pulmonary arterial hypertension (PAH). Moreover, PAH-patients with lower levels of vitD have worse prognosis. We hypothesize that recovering optimal levels of vitD in an animal model of PAH previously depleted of vitD improves the hemodynamics, the endothelial dysfunction and the ionic remodeling. Methods: Male Wistar rats were fed a vitD-free diet for five weeks and then received a single dose of Su5416 (20 mg/Kg) and were exposed to vitD-free diet and chronic hypoxia (10% O₂) for three weeks to induce PAH. Following this, vitD deficient rats with PAH were housed in room air and randomly divided into two groups: (a) continued on vitD-free diet or (b) received an oral dose of 100,000 IU/Kg of vitD plus standard diet for three weeks. Hemodynamics, pulmonary vascular remodeling, pulmonary arterial contractility, and K⁺ currents were analyzed. Results: Recovering optimal levels of vitD improved endothelial function, measured by an increase in the endothelium-dependent vasodilator response to acetylcholine. It also increased the activity of TASK-1 potassium channels. However, vitD supplementation did not reduce pulmonary pressure and did not ameliorate pulmonary vascular remodeling and right ventricle hypertrophy. Conclusions: Altogether, these data suggest that in animals with PAH and severe deficit of vitD, restoring vitD levels to an optimal range partially improves some pathophysiological features of PAH.

Vitamin D Deficiency Reduces Vascular Reactivity of Coronary Arterioles in Male Rats

BACKGROUND

Vitamin D deficiency (VDD) may be considered an independent cardiovascular (CV) risk factor, and it is well known that CV risk is higher in males. Our goal was to investigate the pharmacological reactivity and receptor expression of intramural coronary artery segments of male rats in cases of different vitamin D supply.

METHODS

Four-week-old male Wistar rats were divided into a control group (n = 11) with optimal vitamin D supply (300 IU/kgbw/day) and a VDD group (n = 11, <0.5 IU/kgbw/day). After 8 weeks of treatment, intramural coronary artery segments were microprepared, their pharmacological reactivity was examined by in vitro microangiometry, and their receptor expression was investigated by immunohistochemistry.

RESULTS

Thromboxane A2 (TXA2)-agonist induced reduced vasoconstriction, testosterone (T) and 17-β-estradiol (E2) relaxations were significantly decreased, a significant decrease in thromboxane receptor (TP) expression was shown, and the reduction in estrogen receptor-α (ERα) expression was on the border of significance in the VDD group.

CONCLUSIONS

VD-deficient male coronary arteries showed deteriorated pharmacological reactivity to TXA2 and sexual steroids (E2, T). Insufficient vasoconstrictor capacity was accompanied by decreased TP receptor expression, and vasodilator impairments were mainly functional. The decrease in vasoconstrictor and vasodilator responses results in narrowed adaptational range of coronaries, causing inadequate coronary perfusion that might contribute to the increased CV risk in VDD.

Supplementation with vitamin D in the COVID-19 pandemic?

The coronavirus disease 2019 (COVID-19) pandemic was declared a public health emergency of international concern by the World Health Organization. COVID-19 has high transmissibility and could result in acute lung injury in a fraction of patients. By counterbalancing the activity of the renin-angiotensin system, angiotensin-converting enzyme 2, which is the fusion receptor of the virus, plays a protective role against the development of complications of this viral infection. Vitamin D can induce the expression of angiotensin-converting enzyme 2 and regulate the immune system through different mechanisms. Epidemiologic studies of the relationship between vitamin D and various respiratory infections were reviewed and, here, the postulated mechanisms and clinical data supporting the protective role of vitamin D against COVID-19-mediated complications are discussed.

Vitamin D supplementation: upper limit for safety revisited?

Vitamin D overdosing includes hypercalcemia, hypercalciuria, and mineral deposits in soft tissues. A safety upper limit of 4000 IU/day, which is consistently accepted, has been challenged, since the risk of adverse events in other systems than calcium-phosphate homeostasis may depend not only on the dose, but on the outcome, the treatment regimen, and possibly the age, sex and vitamin D status. The therapeutic window of vitamin D supplementation may be narrower than hitherto recognized. The prevention and/or correction of vitamin D deficiency/insufficiency with 800–1000 IU/daily of vitamin D or 10 µg/day of calcifediol are safe. Because of their potential harm, larger doses given on the long term or in intermittent regimens should not be selected.

COVID-19 Disease and Vitamin D: A Mini-Review

Novel coronavirus disease (COVID-19) pandemic caused by SARS-CoV-2, for which there is no effective treatment except employing prevention strategies, has already instituted significant number of deaths. In this review, we provide a scientific view on the potential role of vitamin D in SARS-CoV-2 virus/COVID-19 disease. Vitamin D is well-known to play a significant role in maintaining the immune health of an individual. Moreover, it induces antimicrobial peptide expression that can decrease viral replication and regulate the levels of pro-inflammatory/anti-inflammatory cytokines. Therefore, supplementation of vitamin D has the potential to reduce the incidence, severity and the risk of death from pneumonia resulting from the cytokine storm of many viral infections including COVID-19. We suggest that supplementation of subjects at high risk of COVID-19 with vitamin D (1.000 to 3.000 IU) to maintain its optimum serum concentrations may be of significant benefit for both in the prevention and treatment of the COVID-19.

Vitamin D in obesity and obesity-related diseases: an overview

Hypovitaminosis D and obesity represent two pandemic conditions sometimes associated with each other. Although it is known that there is a close relationship between these two health problems, the underlying pathophysiological mechanism has not yet been fully clarified. In fact, on the one hand, obesity per se seems to involve low circulating levels of vitamin D due to low sun exposure, physical activity, and intake of foods rich in vitamin D, volumetric dilution and sequestration in the adipose tissue. Conversely, since preadipocytes and adipocytes express the receptors and are involved in the metabolism of vitamin D it would seem that low levels of this vitamin may be involved in adipogenesis and therefore in the development of obesity. This connection is extremely important when considering obesity-related diseases. In fact, low vitamin D levels and severe obesity are significantly associated with some cardio-metabolic risk factors, including high Body Mass Index, waist circumference, blood pressure, impaired lipid and glycemic profile and insulin resistance, as they would seem associated with worse cardiovascular outcomes and higher cancer incidence and mortality. Therefore, the purpose of this review was to examine the recent evidence linking low vitamin D status, obesity and obesity-related diseases, highlighting the scientific achievements and the gaps to be filled with further investigations.

Effect of monthly vitamin D on diverticular disease hospitalization: Post-hoc analysis of a randomized controlled trial

BACKGROUND & AIMS

Some studies have linked low vitamin D status and high risk of diverticular disease, but the causal relationship between vitamin D and diverticular disease remains unclear; clinical trial data are warranted. The objective was to assess the efficacy of vitamin D₃ supplementation on diverticular disease hospitalization.

METHODS

Post-hoc analysis of a community-based randomized double-blind placebo-controlled trial (RCT) with 5108 participants randomized to receive monthly 100,000 IU vitamin D (n = 2558) or identical placebo (n = 2550). The outcome was time to first diverticular disease hospitalization from randomization to the end of intervention (July 2015), including a prespecified subgroup analysis in participants with baseline deseasonalized 25-hydroxyvitamin D (25(OH)D) levels < 50 nmol/L.

RESULTS

Over a median of 3.3 years follow-up, 74 participants had diverticular disease hospitalization. There was no difference in the risk of diverticular disease hospitalization between vitamin D supplementation (35/2558 = 1.4%) and placebo (39/2550 = 1.5%) groups (adjusted hazard ratio (HR) = 0.90; p = 0.65), although in participants with deseasonalized 25(OH)D < 50 nmol/L (n = 1272), the risk was significantly lower in the vitamin D group than placebo (HR = 0.08, p = 0.02).

DISCUSSION

Monthly 100,000 IU vitamin D₃ does not reduce the risk of diverticular disease hospitalization in the general population. Further RCTs are required to investigate the effect of vitamin D supplementation on the diverticular disease in participants with low 25(OH)D levels.

Breaking the vicious circle of diet, malnutrition and oral health for the independent elderly

Aging impairs senses, mastication, oral status and function, causing nutritional needs and diet insufficiencies. The present needs of independent older adults suggest that health research and oral health care should shift from reductionist disease management to integral and personal treatment plans, including lifestyle, psychological, nutritional and oral health coaching approaches. Dentists and other medical professionals that work in the field of gerodontology should be educated on the macro and micronutrient needs of the elderly and incorporate certain nutritional plans early in the life of their patients with their approval and cooperation, in order to postpone tooth loss and masticatory impairment. Old recipes such as the Mediterranean diet should be kept as a base for all the elderly and be enriched in a customized interpersonal way from the dentist as well as the medical professional according to the specific needs of one's oral and general health status. In this nonsystematic review paper, the basic aspects of the vicious cycle of nutrition and oral health status are discussed and suggestions of major nutrients' influence and needs for independent elders are reported. Based on the scientific data collected, suggestions are made for the food industry for better quality and dosage of foods for this category of individuals. Such strategies can be a whole new area of interest for the food industry in order to obtain better quality of food packaging for the independent OA with accepted texture, odor, colors, macronutrients and micronutrients' consistency and in specific portions.

Plasma 25-Hydroxyvitamin D Levels and VDR Gene Expression in Peripheral Blood Mononuclear Cells of Leukemia Patients and Healthy Subjects in Central Kazakhstan

Low blood levels of the vitamin D metabolite 25-hydroxyvitamin D [25(OH)D] have been associated with an increased risk and poorer outcomes of various cancers, including hematological malignancies. The Central Kazakhstan area has a relatively high incidence rate of leukemia. However, the relationship between vitamin D status and leukemia or other types of cancer in Kazakhstan has not yet been addressed. Therefore, in this first pilot single-center study conducted in Central Kazakhstan, we compared plasma levels of 25(OH)D and the vitamin D receptor (VDR) gene expression levels in peripheral blood mononuclear cells of patients with leukemia and demographically matching healthy volunteers. The levels of 25(OH)D in patients were found to be significantly lower (10.8 ± 7.0 ng/mL; n = 31) than in healthy subjects (21.6 ± 7.8 ng/mL; n = 34; p < 0.0001). A similar difference was observed in both younger (<60 years old) and older (>60 years old) participants, though there was no association between 25(OH)D concentration and age within the patient group. In female patients, 25(OH)D levels were significantly lower than in male patients (p = 0.04). No significant seasonal variations of 25(OH)D were observed in either the patient or the control group. VDR gene expression levels appeared to be similar in leukemia patients and healthy subjects, and no correlation between the cellular VDR expression and plasma 25(OH)D concentrations was observed in either group of participants. We did not observe a significant association of 25(OH)D or VDR levels and overall survival of leukemia patients. This observational study conducted for the first time in Kazakhstan supports previous findings demonstrating reduced blood 25(OH)D levels in cancer (leukemia) patients. Larger studies are required to determine whether low 25(OH)D plasma concentrations represent a risk factor for leukemia development and/or progression.

Vitamin D insufficiency is associated with subclinical atherosclerosis in HIV-1-infected patients on combination antiretroviral therapy

Objectives: Vitamin D insufficiency has been associated with faster progression of atherosclerosis and increased cardiovascular disease risk, but limited data are available in HIV-infected people. So, we examined potential correlation between vitamin D status and atherosclerosis in people living with HIV.Methods: A cross-sectional study was performed including adult HIV-infected patients on stable antiretroviral therapy, aged 40-60 years, and with a recent carotid ultrasonography. Subclinical atherosclerosis was defined as a carotid intima-media thickness (IMT) ≥0.9 mm at any site. Patients with diabetes mellitus or atherosclerotic cardiovascular disease were excluded.Results: On the whole, 188 patients were enrolled: 86.2% were men and the mean age was 49.1 years. The mean CD4 T lymphocyte count was 567 cells/mm³, 176 (93.6%) had plasma HIV RNA <20 copies/mL, 51.1% were smoker, 29.2% had hypertension, 27.7% metabolic syndrome, and 44.7% LDL cholesterol >150 mg/dL. The mean serum concentration of vitamin D was 35.2 ng/mL, and 84 (44.6%) patients had a vitamin D insufficiency (<30 ng/mL). Subclinical atherosclerosis was reported in 105 (55.8%) and the mean vitamin D concentration was significantly lower among patients with subclinical atherosclerosis than among those without (18.2 vs 41.3 ng/mL, p < 0.001). Moreover, the multivariate linear regression analysis adjusted by confounding factors showed an independent association between subclinical atherosclerosis and vitamin D insufficiency, age >50 years, smoking, hypertension, metabolic syndrome, higher BMI, higher LDL cholesterol, longer duration of HIV infection, lower nadir CD4 cell count, and longer exposure to boosted protease inhibitors.Conclusion: In our study, vitamin D insufficiency is significantly associated with subclinical atherosclerosis, so its role in HIV-associated cardiovascular disease should be further evaluated as a possible target for intervention.