Vitamin D Metabolism and Guidelines for Vitamin D Supplementation

Vitamin D supplementation and calcium: Many-faced gods or nobody in fighting against Corona Virus Disease 2019

In December 2019, Corona Virus Disease 2019 (COVID-19) was first identified and designated as a pandemic in March 2020 due to rapid spread of the virus globally. At the beginning of the pandemic, only a few treatment options, mainly focused on supportive care and repurposing medications, were available. Due to its effects on immune system, vitamin D was a topic of interest during the pandemic, and researchers investigated its potential impact on COVID-19 outcomes. However, the results of studies about the impact of vitamin D on the disease are inconclusive. In the present narrative review, different roles of vitamin D regarding the COVID-19 have been discussed to show that vitamin D supplementation should be recommended carefully.

Natural products for the treatment of age-related macular degeneration

BACKGROUND

Age-related macular degeneration (AMD) is a chronic retinal disease that significantly influences the vision of the elderly.

PURPOSE

There is no effective treatment and prevention method. The pathogenic process behind AMD is complex, including oxidative stress, inflammation, and neovascularization. It has been demonstrated that several natural products can be used to manage AMD, but systematic summaries are lacking.

STUDY DESIGN AND METHODS

PubMed, Web of Science, and ClinicalTrials.gov were searched using the keywords "Biological Products" AND "Macular Degeneration" for studies published within the last decade until May 2023 to summarize the latest findings on the prevention and treatment of age-related macular degeneration through the herbal medicines and functional foods.

RESULTS

The eligible studies were screened, and the relevant information about the therapeutic action and mechanism of natural products used to treat AMD was extracted. Our findings demonstrate that natural substances, including retinol, phenols, and other natural products, prevent the development of new blood vessels and protect the retina from oxidative stress in cells and animal models. However, they have barely been examined in clinical studies.

CONCLUSION

Natural products could be highly prospective candidate drugs used to treat AMD, and further preclinical and clinical research is required to validate it to control the disease.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system’s surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.

Unraveling colorectal cancer prevention: The vitamin D - gut flora - immune system nexus

Colorectal cancer (CRC) is one of the most common cancers diagnosed in the world. Although environmental and genetic factors play a major role in the pathogenesis of CRC, extensive research has suggested that vitamin D may play a pivotal role in the development of CRC. Vitamin D, primarily obtained through sunlight exposure, dietary sources, and supplements, has long been recognized for its essential functions in maintaining health, including immune regulation. This article delves into the intricate relationship between vitamin D, the immune system, gut flora, and the prevention of CRC. It presents a synthesis of epidemiological data, experimental studies, and clinical trials, highlighting the mechanisms by which vitamin D influences immune cell function, cytokine production, and inflammation. By enhancing the immune system’s surveillance and anti-tumor activity, vitamin D may offer a promising avenue for CRC prevention. Furthermore, this comprehensive review delves into the prospective clinical applications of vitamin D supplementation and delineates the forthcoming avenues of research in this dynamic domain. Additionally, the paper tentatively outlines a spectrum of prophylactic impacts of vitamin D on CRC, emphasizing its significant potential in reducing CRC risk through shedding light on its mechanisms, encompassing antineoplastic mechanisms, influences on the immune system, and modulation of the gut microbiome.

Determining the vitamin D supplementation duration to reach an adequate or optimal vitamin D status and its effect on blood lipid profiles: a longitudinal study

BACKGROUND

Recently, Serum vitamin D (Vit. D) levels evaluation and the use of Vit. D supplements have increased substantially. There is no specific guideline for the duration of Vit. D supplementation, so yet Vit. D supplementation duration has remained a critical and controversial issue. This study aimed to determine the vit. D supplementation duration to reach an adequate or optimal Vit. D status and its effect on lipid profile.

METHODS

In this longitudinal study, 345 women with different status of Vit. D levels were enrolled and followed up for one year. Eligible participants received 50,000 IU Vit. D3 (cholecalciferol) once a month for 12 consecutive months. The serum Vit. D levels and lipid profiles were measured at baseline, 3rd, 6th, and 12th months after the intervention. Participants were categorized based on Vit. D level at baseline into deficiency (< 20 ng/mL), inadequate (20-30 ng/mL), and adequate (> 30 ng/mL) groups, and the data were compared at different times between the three groups.

RESULTS

Three deficiency (n = 73), inadequate (n = 138) and adequate (n = 134) groups of participants were followed. In all participants the average amount of Vit. D level changes were 8 ng/mL after one year of supplementation. The mean changes of serum Vit. D level in 6th and 12th months vs. 3th month was as below: In deficiency group: 4.08 ± 0.85 and 10.01 ± 1.02 ng/mL; (p < 0.001), in inadequate group: 3.07 ± 0.59 and 7.26 ± 0.78 ng/mL; (p = 0.001) and in adequate group: 2.02 ± 0.88 and 6.44 ± 1.005 ng/ml; (p = 0.001). Lipid profiles were improved in three groups. So, the mean changes of lipid profiles at the end of the study comparing with the baseline were: -5.86 ± 2.09, -7.22 ± 1.43 and - 6.17 ± 1.72 (mg/dl) for LDL (p < 0.05); -12.24 ± 3.08, -13.64 ± 3.21 and - 17.81 ± 2.94 (mg/dl) for cholesterol (p < 0.05) in deficiency, inadequate and adequate groups, respectively. For triglyceride, the mean changes were - 13.24 ± 5.78 and - 15.85 ± 7.49 (mg/dl) in deficiency and adequate groups, respectively (p < 0.05). Although the triglyceride decreased in the inadequate group at the end of the study but this difference was not significant (p = 0.67).

CONCLUSION

Taking of 50,000 IU Vit. D 3 monthly for 12 months resulted in reaching its level to adequate level in both deficiency and insufficient groups; however, in the adequate group its level did not reach above than 50 ng/mL. Therefore, 50,000 IU Vit. D3 supplementation monthly for one year can have beneficial effects on lipid profiles and there is no risk of toxicity in healthy women.

Emerging perspectives: unraveling the anticancer potential of vitamin D3

Vitamin D3, a fat-soluble vitamin known for its critical function in calcium homeostasis and bone health, is gaining interest for its anticancer properties. Observational studies have suggested a negative relationship between vitamin D levels and the incidence of some malignancies throughout the years, prompting substantial investigation to find its anticancer effects. The purpose of this comprehensive review is to investigate the diverse function of vitamin D3 in cancer prevention and therapy. We explored the molecular mechanism underlying its effects on cancer cells, which range from cell cycle control and death to angiogenesis and immune response modulation. Insights from in vitro and in vivo studies provide valuable evidence supporting its anticancer potential. Furthermore, we look at epidemiological and clinical studies that investigate the relationship between vitamin D3 levels and cancer risk or treatment results. Vitamin D3 supplementation's safety profile and cost-effectiveness increase its attractiveness as an adjuvant therapy in conjunction with traditional treatment regimens. Our critical review of the current literature provides an in-depth understanding of vitamin D3's anticancer effect, covering the obstacles and possibilities in realizing its promise for cancer prevention and therapy. The findings of this study might pave the way for the development of innovative treatment techniques that take use of the advantages of vitamin D3 to fight cancer and improve patient care. As research progresses, a better understanding of vitamin D3's anticancer processes will surely simplify its incorporation into personalized cancer care techniques, hence enhancing patient outcomes in the battle against cancer.

The Power of Vitamin D: Is the Future in Precision Nutrition through Personalized Supplementation Plans?

In the last few decades, vitamin D has undeniably been one of the most studied nutrients. Despite our ability to produce vitamin D through sunlight exposure, its presence in several natural food sources and fortified foods, and its widespread availability as a dietary supplement, vitamin D deficiency is a serious public health problem, affecting nearly 50% of the global population. Low serum levels of vitamin D are being associated with increased susceptibility to numerous health conditions, including respiratory infections, mental health, autoimmune diseases, and different cancer types. Although the association between vitamin D status and health is well-established, the exact beneficial effects of vitamin D are still inconclusive and indefinite, especially when considering the prevention and treatment of different health conditions and the determination of an appropriate dosage to exert those beneficial effects in various population groups. Therefore, further research is needed. With constant improvements in our understanding of individual variations in vitamin D metabolism and requirements, in the future, precision nutrition and personalized supplementation plans could prove beneficial.

Mushrooms: a food-based solution to vitamin D deficiency to include in dietary guidelines

Vitamin D deficiency and insufficiency is a public health issue, with low dietary vitamin D intakes a contributing factor. Rates of vitamin D deficiency are 31% in Australia, and up to 72% in some regions globally. While supplementation is often prescribed as an alternative to additional sun exposure, complementary approaches including food-based solutions are needed. Yet, food-centric dietary guidelines are not always adequate for meeting vitamin D needs. Edible mushrooms such as Agaricus bisporus can produce over 100% of vitamin D recommendations (10 μg/day, Institute of Medicine) per 75 g serve (18 μg) on exposure to UV-light, with the vitamin D2 produced showing good stability during cooking and processing. However, mushrooms are overlooked as a vitamin D source in dietary guidelines. Our dietary modelling shows that four serves/week of UV-exposed button mushrooms can support most Australian adults in meeting vitamin D recommendations, and UV-exposed mushrooms have been found to increase vitamin D status in deficient individuals. While recent evidence suggests some differences between vitamin D2 and vitamin D3 in physiological activities, vitamin D2 from mushrooms can be part of a larger solution to increasing dietary vitamin D intakes, as well as an important focus for public health policy. Mushrooms exposed to UV represent an important tool in the strategic toolkit for addressing vitamin D deficiency in Australia and globally. Health authorities lead the recognition and promotion of mushrooms as a natural, vegan, safe, and sustainable vitamin D food source.

Association between vitamin D levels and risk of periodontitis in patients with metabolic syndrome

Background/purpose

The relationship between Vitamin D (VD) and periodontitis in patients with metabolic syndrome (MetS) was unclear. This study was to investigate the relationship between VD and periodontitis in MetS patients.

Materials and methods

This cross-sectional study collected the data of 2165 MetS patients from the National Health and Nutrition Examination Survey (NHANES). The weighted univariate and multivariable Logistic regression models were applied to identify covariates and evaluate the association between 25-hydroxy vitamin D (25(OH)D) [25(OH)D]2 + 25(OH)D3 and periodontitis in patients. Odds ratio (OR) [95% confidence interval (CI)] was effect size. Subgroup analysis was performed in people with or without diabetes, dyslipidemia, hypertension, cardiovascular disease (CVD) and central obesity groups.

Results

In the unadjusted model, compared with patients with 25(OH)D2 + 25(OH)D3 < 50 nmol/L, those with 25(OH)D2 + 25(OH)D3 ≥ 50 nmol/L might be associated with decreased risk of periodontitis in MetS patients (OR = 0.70, 95% CI: 0.57-0.85). After adjusting for confounders including age, gender, race, education, poverty income ratio (PIR), smoking, diabetes, VD intake and supplement and number of missing teeth, 25(OH)D2 + 25(OH)D3 ≥ 50 nmol/L was correlated with reduced risk of periodontitis in MetS patients (OR = 0.76, 95% CI: 0.60-0.97). Subgroup analysis revealed that in patients with CVD (OR = 0.60, 95% CI: 0.37-0.98), dyslipidemia (OR = 0.75, 95% CI: 0.57-0.97), and patients with central obesity (OR = 0.73, 95% CI: 0.57-0.95), decreased risk of periodontitis was identified in 25(OH)D2 + 25(OH)D3 ≥ 50 nmol/L.

Conclusion

VD was associated with the risk of periodontitis in patients with MetS, which suggest the importance of VD supplement in patients with MetS and provide a reference for the management of periodontitis in patients with MetS.

Postprandial Micronutrient Variability and Bioavailability: An Interventional Meal Study in Young vs. Old Participants

This study explores age- and time-dependent variations in postprandial micronutrient absorption after a micronutrient-rich intervention meal within the Biomiel (bioavailability of micronutrients in elderly) study. Comprising 43 healthy participants, the study compares young (n = 21; mean age 26.90 years) and old (n = 22; mean age 66.77 years) men and women, analyzing baseline concentrations and six-hour postprandial dynamics of iron (Fe), copper (Cu), zinc (Zn), selenium (Se), iodine (I), free zinc (fZn), vitamin C, retinol, lycopene, β-carotene, α-tocopherol, and γ-tocopherol, along with 25(OH) vitamin D (quantified only at baseline). Methodologically, quantifications in serum or plasma were performed at baseline and also at 90, 180, 270, and 360 min postprandially. Results reveal higher baseline serum Zn and plasma lycopene concentrations in the young group, whereas Cu, Se, Cu/Zn ratio, 25(OH) vitamin D, α-tocopherol, and γ-tocopherol were higher in old participants. Postprandial variability of Zn, vitamin C, and lycopene showed a strong time-dependency. Age-related differences in postprandial metabolism were observed for Se, Cu, and I. Nevertheless, most of the variance was explained by individuality. Despite some limitations, this study provides insights into postprandial micronutrient metabolism (in serum/plasma), emphasizing the need for further research for a comprehensive understanding of this complex field. Our discoveries offer valuable insights for designing targeted interventions to address and mitigate micronutrient deficiencies in older adults, fostering optimal health and well-being across the lifespan.

Vitamin D and cancer

The role of vitamin D in the prevention of chronic diseases including cancer, has received a great deal of attention during the past few decades. The term "Cancer" represents multiple disease states with varying biological complexities. The strongest link between vitamin D and cancer is provided by ecological and studies like observational, in preclinical models. It is apparent that vitamin D exerts diverse biological responses in a tissue specific manner. Moreover, several human factors could affect bioactivity of vitamin D. The mechanism(s) underlying vitamin D initiated anti-carcinogenic effects are diverse and includes changes at the muti-system levels. The oncogenic environment could easily corrupt the traditional role of vitamin D or could ensure resistance to vitamin D mediated responses. Several researchers have identified gaps in our knowledge pertaining to the role of vitamin D in cancer. Further areas are identified to solidify the role of vitamin D in cancer control strategies.

Ukrainian Consensus on Diagnosis and Management of Vitamin D Deficiency in Adults

Vitamin D deficiency (VDD) is a global problem, however, there were no Ukrainian guidelines devoted to its screening, prevention, and treatment, which became the reason for the Consensus creation. This article aimed to present the Consensus of Ukrainian experts devoted to VDD management. Following the creation of the multidisciplinary Consensus group, consent on the formation process, drafting and fine-tuning of key recommendations, and two rounds of voting, 14 final recommendations were successfully voted upon. Despite a recent decrease in VDD prevalence in Ukraine, we recommend raising awareness regarding VDD's importance and improving the strategies for its decline. We recommend screening the serum 25-hydroxyvitamin D (25(OH)D) level in risk groups while maintaining a target concentration of 75-125 nmol/L (30-50 ng/mL). We recommend prophylactic cholecalciferol supplementation (800-2000 IU/d for youthful healthy subjects, and 3000-5000 IU/d for subjects from the risk groups). For a VDD treatment, we recommend a short-term administration of increased doses of cholecalciferol (4000-10,000 IU/d) with 25(OH)D levels monitored after 4-12 weeks of treatment, followed by the use of maintenance doses. Additionally, we recommend assessing serum 25(OH)D levels before antiosteoporotic treatment and providing vitamin D and calcium supplementation throughout the full course of the antiosteoporotic therapy.

Has a High Dose of Vitamin D3 Impacted Health Conditions in Older Adults?-A Systematic Review and Meta-Analysis Focusing on Dose 100,000 IU

BACKGROUND

Older adults are prone to vitamin D3 (VD3) deficiency, which may impair their health. A high dose of VD3 (HDVD3 = 100,000 IU) could improve their 25-hydroxyvitamin D3 [25(OH)D] level and health outcomes. However, evidence for such a beneficial effect of HDVD3 in older adults coming from clinical trials is mixed.

OBJECTIVE

To review the literature on the efficacy of a single dose of 100,000 IU of VD3 in older people.

METHODS

We searched PubMed/Medline, Science Direct, and NIH's clinical trials registry for clinical studies on the effect of a single high dose of VD3 on various health outcomes in older people. We also performed a meta-analysis using the standardized mean difference to assess the effect of VD3 on its blood level. Due to expected high heterogeneity, its amount (i.e., tau2) was estimated using the DerSimonian-Laird estimator. To estimate tau2, the Q-test for heterogeneity and the I2 statistic were calculated.

RESULTS

Search results identify 13 studies that reported diverse health outcomes, such as lung and cardiovascular function, skin cancer progression, intensive care unit mortality, immune system response, and bone density. The meta-analysis showed a significant increase in 25(OH)D blood levels after treatment in 10 studies, with an average standardized mean difference of 2.60 ng/mL (95% CI: 2.07 to 3.13). Their results suggested that a single high dose of VD3 may benefit intensive care unit patients and skin cancer patients in remission. However, evidence for other beneficial health effects of HDVD3 was mixed due to high heterogeneity among studies.

CONCLUSIONS

A single high dose of VD3 may positively affect some health outcomes in older people, possibly due to its pleiotropic and immunomodulatory effects. However, the evidence needs to be more extensive and consistent, and more rigorous studies are required to confirm the benefits and safety of VD3 high doses in older patients.

Mexican consensus on cow's milk protein allergy

BACKGROUND

The aim of this study is to present the current views of a diverse group of experts on the diagnosis and treatment of Cow's Milk Protein Allergy (CMPA) in children under 2 years of age in Mexico.

MATERIAL AND METHODS

The study, led by a scientific committee of five experts in CMPA, was divided into six phases, including a modified Delphi process. A total of 20 panelists, all of whom were pediatric specialists, participated in administering a comprehensive 38-item questionnaire. The questionnaire was divided into two blocks: Diagnosis and Treatment (20 items each).

RESULTS

Consensus was reached on all the proposed items, with an agreement rate of over 70% for each of them. As a result, a diagnostic and treatment algorithm was developed that emphasized the reduction of unnecessary diagnostic studies and encouraged breastfeeding whenever possible. In cases where breast milk is not available, appropriate use of hypoallergenic formulas was recommended. In addition, recommendations on treatment duration and gradual reintroduction of cow's milk protein were provided.

CONCLUSIONS

The recommendations endorsed by 20 Mexican pediatricians through this study are applicable to everyday clinical practice, thereby enhancing the diagnosis and treatment of children under 2 years of age with CMPA. This, in turn, will foster improved health outcomes and optimize the utilization of healthcare resources.

Relationship between vitamin D and adolescents' hypothyroidism - a cross-sectional study

Introduction

To detect the relationship between 25(OH)D and hypothyroidism in adolescents.

Material and methods

A total of 180 adolescents were included in the current study, which was conducted in West Kazakhstan (Aktobe) over 2 years. After thorough evaluation, blood samples were collected from the studied participants to measure the thyroid stimulating hormone (TSH), free thyroxine (T4), prolactin, glycosylated haemoglobin, and 25(OH)D. Participants were classified into a 25(OH)D-deficient group (study group) and controls. MedCalc and correlation analysis (Pearson's correlation) were used to detect the odds of hypothyroidism and the relationship between 25(OH)D and adolescents' hypothyroidism, respectively.

Results

Thyroid-stimulating hormone was statistically higher in the 25(OH)D-deficient group than in the normal controls (3.71 ±1.4 mIU/ml vs. 2.67 ±0.99) (p = 0.0006), and the free T4 was statistically lower in the 25(OH)D-deficient group than in normal controls (1.4 ±0.56 ng/ml vs. 1.5 ±0.4) (p = 0.0008). The 25(OH)D deficient group had higher odds of subclinical (OR 4.89; p = 0.016), and clinical hypothyroidism (OR 4.3; p = 0.013) compared to controls. A significant negative correlation between the 25(OH)D and TSH (r = -0.793; p < 0.00001), and a significant positive correlation between the 25(OH)D and free T4 (r 0.55; p < 0.00001) were detected in this study.

Conclusions

The thyroid-stimulating hormone was statistically higher and the free T4 was statistically lower in the 25(OH)D-deficient group than in normal controls. The 25(OH)D-deficient group had higher odds of both subclinical and clinical hypothyroidism compared to controls. A significant negative correlation between the 25(OH)D and TSH, and a significant positive correlation between the 25(OH)D and the free T4 were detected in this study.

Relation between vitamin D and adolescents' serum prolactin

Introduction

To detect whether there is a relation between vitamin D (Vit. D) and adolescents' serum prolactin (PRL) or not.

Material and methods

Hundred and seventy-six adolescent girls were recruited for the current study, which was conducted in West Kazakhstan (Aktobe) over two years. After thorough evaluation, blood samples were taken from adolescents to measure thyroid stimulating hormone (TSH), free thyroxine (T4), PRL, glycosylated hemoglobin and 25(OH)D. The studied adolescents were classified into study group [25(OH)D deficient] and controls [normal 25(OH)D]. The acquired adolescents' variables were analyzed using the Student t-test and Pearson's correlation.

Results

The serum TSH and PRL were statistically higher in the study group than normal controls (3.73 ±1.45 mIU/ml and 47.5 ±7.6 ng/ml vs. 2.67 ±1.0 and 10.8 ±5.1, respectively), (p = 0.0003 and p = 0.0001, respectively). The free T4 was statistically lower in the study group than normal controls (1.4 ±0.6 ng/ml vs. 1.5 ±0.4), (p = 0.0001). Strong negative associations between the serum PRL and 25(OH)D [r = -0.803 (p < 0.00001)], and between the serum PRL and free T4 [r = -0.6959 (p < 0.00001)] were detected in this study. Additionally, there was a strong positive association between the serum PRL and TSH [r = 0.8137 (p < 0.00001)].

Conclusions

A strong negative association between the serum PRL and 25(OH)D and a strong positive association between the serum PRL and TSH were detected in this study. This study recommends further studies to confirm the relation between Vit. D and PRL and screening Vit. D deficient adolescents for PRL and thyroid disorders.

Effects of vitamin D supplementation on cardiometabolic parameters among patients with metabolic syndrome: A systematic review and GRADE evidence synthesis of randomized controlled trials

Various pathophysiologic mechanisms were proposed to underlie the effect of vitamin D on MetS components. In this systematic review, we reviewed randomized control clinical trials to verify whether vitamin D supplementation (VDS) at different doses is effective concomitantly in controlling high-density lipoprotein cholesterol (HDL-c), triglycerides (TG), fasting glucose level, blood pressure, and central obesity in adults diagnosed with MetS. The following scientific databases were searched from 1998 until April 2023: EMBASE, MEDLINE (PubMed), Web of Science, Latin American and Caribbean Health Sciences Literature (Lilacs), the Cochrane Central Register of Controlled Trials, clinicaltrial.gov, and Google Scholar. No language restrictions were applied. Seven studies were included, and they showed a high level of heterogeneity. All studies reported a significant increase in serum 25(OH)D levels in the intervention groups. Of these, only two noted a significant decrease in triglyceride (TG) level and waist circumference. However, the certainty levels of the evidence rating were very low and low for triglyceride (TG) level and waist circumference, respectively, and moderate for fasting glucose level, blood pressure, and HDL-c. In conclusion, despite these benefits, considering the low certainty, the evidence does not support that VDS decreases triglyceride (TG) level and waist circumference in adults with MetS.

Biological variation of plasma 25-Hydroxyvitamin D3, Serum vitamin B12, folate and ferritin in Turkish healthy subject

Biological variation (BV) plays a crucial role in determining analytical performance specifications, assessing serial measurements of individuals, and establishing the use of population-based reference intervals. Our study aimed to calculate the BV and BV-based quality goals of 25-hydroxyvitamin D3 (25-OH D3), ferritin, folate and vitamin B12 tests. We included a total of 22 apparently healthy volunteers (9 women and 13 men) aged 18-55 years in the study that we conducted in Turkey. Blood samples were collected from the participants once a week for five weeks. Serum ferritin, folate and vitamin B12 levels were measured using immunochemical method, while plasma 25-OH D3 levels were determined using the high-performance liquid chromatography method. Analysis of variance (ANOVA) was used to estimate analytical variation(CVA), within-subject BV(CVI) and between-subject BV(CVG). The individuality index (II) and reference change value (RCV) were calculated based on these data. The CVI of 25-OH D3, ferritin, folate, and vitamin B12 were found to be 1.8% (0.6%-2.5%), 16.9% (14.4%-20.2%), 10.7% (9.2%-12.7%), and 8.6% (6.8%-10.5%), respectively. CVG were 44.2% (34.3%-69.9%), 132% (87.7%-238%), 19.4% (14.4%-28.8%), and 39.6% (29.8%-59.0%) for the same biomarkers, while CVA were 3.2% (2.81%-3.71%), 3.5% (3.1%-4.1%), 4.0% (3.5%-4.6%), and 7.5% (6.6%-8.6%), respectively. The II values for 25-OH D3, ferritin, folate, and vitamin B12 were calculated as 0.04, 0.13, 0.55, and 0.22, respectively. The RCV were 10.2%, 47.8%, 31.7%, and 31.6%, respectively. Because the tests analyzed in this study exhibit high individuality, RCV should be preferred rather than population-based reference ranges in clinical interpretation of results.

Calcifediol: Mechanisms of Action

Due to its essential role in calcium and phosphate homeostasis, the secosteroid hormone calcitriol has received growing attention over the last few years. Calcitriol, like other steroid hormones, may function through both genomic and non-genomic mechanisms. In the traditional function, the interaction between the biologically active form of vitamin D and the vitamin D receptor (VDR) affects the transcription of thousands of genes by binding to repeated sequences present in their promoter region, named vitamin D-responsive elements (VDREs). Non-transcriptional effects, on the other hand, occur quickly and are unaffected by inhibitors of transcription and protein synthesis. Recently, calcifediol, the immediate precursor metabolite of calcitriol, has also been shown to bind to the VDR with weaker affinity than calcitriol, thus exerting gene-regulatory properties. Moreover, calcifediol may also trigger rapid non-genomic responses through its interaction with specific membrane vitamin D receptors. Membrane-associated VDR (mVDR) and protein disulfide isomerase family A member 3 (Pdia3) are the best-studied candidates for mediating these rapid responses to vitamin D metabolites. This paper provides an overview of the calcifediol-related mechanisms of action, which may help to better understand the vitamin D endocrine system and to identify new therapeutic targets that could be important for treating diseases closely associated with vitamin D deficiency.

The Sunlight-Vitamin D Connection: Implications for Patient Outcomes in the Surgical Intensive Care Unit

This review delves into the intricate relationship between Vitamin D and patient outcomes in the Surgical Intensive Care Unit (SICU). Vitamin D, known for its multifaceted roles in immune modulation, inflammation regulation, and maintenance of calcium homeostasis, emerges as a pivotal factor in the care of critically ill patients. Our exploration reveals a high prevalence of Vitamin D deficiency in the SICU, primarily attributable to limited sunlight exposure, comorbidities, and medication use. Importantly, Vitamin D status impacts infection rates, mortality, and length of stay in the SICU, making it a clinically relevant consideration. Mechanistic insights into the immunomodulatory and anti-inflammatory effects of Vitamin D shed light on its potential benefits in critical care. However, challenges, including accurate assessment, individualised supplementation, and ethical considerations regarding sunlight exposure, are evident. The prospect of personalised Vitamin D supplementation strategies offers promise for optimising patient care. In conclusion, the Sunlight-Vitamin D Connection holds significant potential to improve outcomes in the SICU, emphasising the importance of further research and tailored approaches for the well-being of critically ill individuals.

Long-term effects of vitamin D supplementation and maintaining sufficient vitamin D on knee osteoarthritis over 5 years

OBJECTIVES

This study aimed to investigate the long-term effect of vitamin D supplementation compared to placebo over 5 years in participants with knee osteoarthritis (OA). We also aimed to describe the effect of maintaining sufficient serum vitamin D levels over five years in knee OA.

METHODS

Participants (n = 173) from the Hobart centre of the Vitamin D Effects on Osteoarthritis (VIDEO) trial were extensively followed up 3 years after the cessation of 2-year investigational treatment. Participants were classified as maintaining sufficient vitamin D (n = 79) and not maintaining sufficient vitamin D (n = 61) groups.

RESULTS

There was no significant difference in change in the knee symptoms, depression, and serum levels of IL6 and hs-CRP between both comparisons after 3 years of cessation of the clinical trial. However, among participants who reported no knee surgery (KS), there was a significant improvement in WOMAC function (β: - 83.7, 95% CI: - 167.3, 0) and depression scores (β: - 1.3, 95% CI: - 2.3, - 0.2) in vitamin D group compared to the placebo group. Similarly, those who maintained adequate vitamin D levels over 5 years had significantly less WOMAC knee pain (β: - 33.9, 95% CI: - 65.7, - 2) and physical dysfunction (β: - 105.5, 95% CI: - 198.2, - 12.8) than participants with vitamin D deficiency over 5 years.

CONCLUSION

Vitamin D supplementation over 2 years or maintaining vitamin D sufficiency for 5 years was not associated with statistically significant differences in change in knee symptom scores over 5 years. However, among participants who did not report KS, 2-year vitamin D supplementation and maintaining sufficient vitamin D was linked to modest improvements in knee symptoms and depression scores in knee OA.

Wearable Device for Cumulative Chlorobenzene Detection and Accessible Mitigation Strategies

Chronic exposure to low concentrations of volatile organic compounds (VOCs), such as chlorobenzene, is not being monitored in industrializing countries, although VOC exposure is associated with carcinogenic, organ-toxic, and endocrine-disrupting effects. Current VOC-sensing technologies are inaccessible due to high cost, size, and maintenance or are ineffective due to poor sensitivity or reliability. In particular, marginalized individuals face barriers to traditional prescription VOC treatments due to cost, lack of transportation, and limited access to physicians; thus, alternative treatments are needed. Here, we created a novel cumulative wearable color-changing VOC sensor with a paper-based polydiacetylene sensor array for chlorobenzene. With a single smartphone picture, the sensor displays 14 days of logged chlorobenzene exposure data, interpreted by machine-learning (ML) techniques, including principal component analysis. Further, we explored the efficacy of affordable and accessible treatment options to mitigate a VOC's toxic effects. Vitamin D and sulforaphane are naturally found in cruciferous vegetables, like broccoli, and can be used to treat chlorobenzene-mediated bone degradation. Our platform combines these components into a smartphone app that photographs the sensor's colorimetric data, analyzes the data via ML techniques, and offers accessible treatments based on exposure data.

Vitamin D Levels in Children During Winter and the Relationship Between Sunscreen and Sun Protection Behaviors

INTRODUCTION

Sunlight is the major source of vitamin D, thus, the use of sunscreens could result in vitamin D insufficiency or deficiency.

OBJECTIVES

Our study aimed to assess serum vitamin D levels in healthy children aged 0-18 years in the winter season and determine the association between sunscreen use and sun protection behaviors on vitamin D status.

METHODS

The demographic data, clothing style, skin type, history of sunburn, history of visiting seaside towns in summer, sun protection behaviors including sunscreen use, wearing sunglasses and hats, and further detailed information about sunscreen use were recorded. Vitamin D status was assessed by measuring blood levels of total 25(OH)D during winter.

RESULTS

Three hundred seventy-six children (172 boys and 204 girls) with a mean age of 128.38±56.39 months were enrolled. The mean serum level of 25(OH)D was 15.32±8.64 ng/mL. The mean values of vitamin D were associated with age, sex, traditional clothing style, having a sunburn history, and sunscreen use (P < 0.05). Adolescents and girls had vitamin D deficiency and inadequacy more than younger children and boys (P < 0.05). Sunscreen use in the adequacy group was lower than in the inadequacy and deficiency groups (P = 0.001). There was no significant difference between vitamin D status according to the sunscreen details (sun protection factor, product source, season, and body areas) (P > 0.05).

CONCLUSIONS

Sunscreen use appears to reduce vitamin D levels measured in winter. Children, especially girls and adolescents, should be exposed to sufficient sunlight to maintain normal serum vitamin D levels. Vitamin D supplementation should be given to children, especially during winter.

Clarifying the Heterogeneity in Response to Vitamin D in the Development, Prevention, and Treatment of Type 2 Diabetes Mellitus: A Narrative Review

In this review, we explore the potential drivers of heterogeneity in response to Vitamin D (VitD) therapy, such as bioavailability, sex-specific response, and autoimmune pathology, in those at risk for and diagnosed with T2DM. In addition, we propose distinct populations for future interventions with VitD. The literature concerning VitD supplementation in the prevention, treatment, and remission of type 2 diabetes mellitus (T2DM) spans decades, is complex, and is often contradictory with mixed findings upon intervention. By association, VitD status is powerfully predictive with deficient subjects reporting greater risk for T2DM, conversion to T2DM from prediabetes, and enhanced response to VitD therapy. Preclinical models strongly favor intervention with VitD owing to the pleiotropic influence of VitD on multiple systems. Additional research is crucial as there remain many questions unanswered that are related to VitD status and conditions such as T2DM. Future research must be conducted to better understand the potentially spurious relationships between VitD status, supplementation, sun exposure, health behaviors, and the diagnosis and management of T2DM. Public health practice can greatly benefit from a better understanding of the mechanisms by which we can reliably increase VitD status and how this can be used to develop education and improve health behaviors.

Non-Melanoma Skin Cancer and Vitamin D: The "Lost Sunlight" Paradox and the Oxidative Stress Explanation

UV radiation (UVR) is responsible for inducing both harmful and beneficial effects on skin health. Specifically, it has been reported to disrupt oxidant and antioxidant levels, leading to oxidative stress conditions in skin tissue. This phenomenon might trigger photo-carcinogenesis, resulting in melanoma, NMSC (non-melanoma skin cancer), such as BCC (basal cell carcinoma) and SCC (squamous cell carcinoma), and actinic keratosis. On the other hand, UVR is essential for the production of adequate vitamin D levels, a hormone with important antioxidant, anticancer and immunomodulatory properties. The exact mechanisms implicated in this two-fold action are not well understood, as there still no clear relation established between skin cancer and vitamin D status. Oxidative stress seems to be a neglected aspect of this complex relation, despite its role in both skin cancer development and vitamin D deficiency. Therefore, the aim of the present study is to examine the correlation between vitamin D and oxidative stress in skin cancer patients. A total of 100 subjects (25 with SCC, 26 with BCC, 23 with actinic keratosis, and 27 controls) were assessed in terms of 25-hydroxyvitamin D (25(OH) D) and redox markers such as thiobarbituric acid reactive substances (TBARS), protein carbonyls, total antioxidant capacity (TAC) in plasma, glutathione (GSH) levels and catalase activity in erythrocytes. The majority of our patients revealed low vitamin D levels; 37% of the subjects showed deficiency (<20 ng/mL) and 35% insufficiency (21-29 ng/mL). The mean 25(OH) D level of the NMSC patients (20.87 ng/mL) was also found to be significantly lower (p = 0.004) than that of the non-cancer patients (28.14 ng/mL). Furthermore, higher vitamin D levels were also correlated with lower oxidative stress (positive correlation with GSH, catalase activity TAC index and negative correlation with TBARS and CARBS indices). NMSC patients diagnosed with SCC showed lower catalase activity values compared to non-cancer patients (p < 0.001), with the lowest values occurring in patients with a chronic cancer diagnosis (p < 0.001) and vitamin D deficiency (p < 0.001). Higher GSH levels (p = 0.001) and lower TBARS levels (p = 0.016) were found in the control group compared to the NMSC group, and to patients with actinic keratosis. Higher levels of CARBS were observed in patients with SCC (p < 0.001). Non-cancer patients with vitamin D sufficiency showed higher TAC values compared to non-cancer patients with vitamin D deficiency (p = 0.023) and to NMSC patients (p = 0.036). The above-mentioned results indicate that NMSC patients reveal increased levels of oxidative damage markers compared to control levels, while vitamin D status plays a critical role in the determination of individuals' oxidative status.

Associations between vitamin D levels and dietary patterns in patients with Hashimoto's thyroiditis

Introduction

Vitamin D insufficiency is a global health problem affecting healthy and diseased individuals, including patients with Hashimoto's thyroiditis (HT). Identifying dietary factors that may affect vitamin D levels and providing dietary guidelines accordingly can alleviate this problem. We therefore aimed to identify still unknown associations of dietary patterns, assessed through the Food Frequency Questionnaire (FFQ) with vitamin D blood levels.

Materials and methods

FFQ was collected from 459 patients from Croatian Biobank of Patients with Hashimoto's thyroiditis (CROHT), while total 25(OH)D was measured from their stored serum samples. We performed linear regression analysis between vitamin D levels and weekly intake of 24 food groups in 459 patients with HT (ALL), and in two disease-severity groups (MILD and OVERT).

Results

The main results of our study are observations of: (1) an inverse association between vitamin D levels and coffee consumption (ALL: β = -0.433, p = 0.005; OVERT: β = -0.62, p = 0.008); (2) an inverse association between vitamin D levels and sweets consumption (ALL: β = -0.195, p = 0.034; OVERT: β = -0.431, p = 0.006); (3) positive association between vitamin D levels and vegetable consumption (ALL: β = 0.182, p = 0.019; OVERT, β = 0.311, p = 0.009). Importantly, effect sizes of all three associations were more prominent in HT patients with prolonged and more severe disease (OVERT).

Conclusion

Further research into the functional and causal relationships of the observed associations is important to provide guidance regarding coffee/sugar intake on vitamin D status. A well-balanced diet can help prevent vitamin D deficiency and improve the quality of life of patients with HT, especially those in later stages of disease characterized by greater metabolic imbalance.

Effect of Single High Dose Vitamin D Substitution in Hospitalized COVID-19 Patients with Vitamin D Deficiency on Length of Hospital Stay

Vitamin D and its role in the coronavirus-19 disease (COVID-19) pandemic has been controversially discussed, with inconclusive evidence about vitamin D3 (cholecalciferol) supplementation in COVID-19 patients. Vitamin D metabolites play an important role in the initiation of the immune response and can be an easily modifiable risk factor in 25-hydroxyvitamin D₃ (25(OH)D₃)-deficient patients. This is a multicenter, randomized, placebo-controlled double-blind trial to compare the effect of a single high dose of vitamin D₃ followed by treatment as usual (TAU) of daily vitamin D₃ daily until discharge versus placebo plus TAU in hospitalized patients with COVID-19 and 25(OH)D₃-deficiency on length hospital stay. We included 40 patients per group and did not observe a significant difference in the median length of hospital stay (6 days in both groups, p = 0.920). We adjusted the length of stay for COVID-19 risk factors (β = 0.44; 95% CI: -2.17-2.22), and center (β = 0.74; 95% CI: -1.25-2.73). The subgroup analysis in patients with severe 25(OH)D₃-deficiency (<25 nmol/L) showed a non-significant reduction in the median length of hospital stay in the intervention group (5.5 vs. 9 days, p = 0.299). The competing risk model with death did not reveal significant differences between the group in the length of stay (HR = 0.96, 95% CI 0.62-1.48, p = 0.850). Serum 25(OH)D₃ level increased significantly in the intervention group (mean change in nmol/L; intervention: +26.35 vs. control: -2.73, p < 0.001). The intervention with 140,000 IU vitamin D₃ + TAU did not significantly shorten the length of hospital stay but was effective and safe for the elevation of serum 25(OH)D₃ levels.

Calcifediol: Why, When, How Much?

Vitamin D deficiency is a constantly growing health problem worldwide. Adults affected with hypovitaminosis D could experience negative consequences on their musculoskeletal system and extra-skeletal health. In fact, an optimal vitamin D status is essential to ensure the correct bone, calcium, and phosphate homeostasis. To improve vitamin D status, it is important to not only increase the intake of food fortified with vitamin D, but also to administer vitamin D supplementation when required. Vitamin D3 (cholecalciferol) is the most widely used supplement. In recent years, the administration of calcifediol (25(OH)D3), the direct precursor of the biologically active form of vitamin D3, as oral vitamin D supplementation has progressively grown. Here, we report the potential medical benefits of some peculiar biological actions of calcifediol, discussing the possible specific clinical scenarios in which the oral intake of calcifediol could be most effective to restore the correct serum levels of 25(OH)D3. In summary, the aim of this review is to provide insights into calcifediol-related rapid non-genomic responses and the possible use of this vitamin D metabolite as a supplement for the treatment of people with a higher risk of hypovitaminosis D.

Vitamin D Metabolites: Analytical Challenges and Clinical Relevance

Recent research activities have provided new insights in vitamin D metabolism in various conditions. Furthermore, substantial progress has been made in the analysis of vitamin D metabolites and related biomarkers, such as vitamin D binding protein. Liquid chromatography tandem mass spectrometric (LC-MS/MS) methods are capable of accurately measuring multiple vitamin D metabolites in parallel. Nevertheless, only 25(OH)D and the biologically active form 1,25(OH)2D are routinely measured in clinical practice. While 25(OH)D remains the analyte of choice for the diagnosis of vitamin D deficiency, 1,25(OH)2D is only recommended in a few conditions with a dysregulated D metabolism. 24,25(OH)2D, free and bioavailable 25(OH)D, and the vitamin D metabolite ratio (VMR) have shown promising results, but technical pitfalls in their quantification, limited clinical data and the lack of reference values, impede their use in clinical practice. LC-MS/MS is the preferred method for the measurement of all vitamin D related analytes as it offers high sensitivity and specificity. In particular, 25(OH)D and 24,25(OH)2D can accurately be measured with this technology. When interpreted together, they seem to provide a functional measure of vitamin D metabolism beyond the analysis of 25(OH)D alone. The determination of VDBP, free and bioavailable 25(OH)D is compromised by unresolved analytical issues, lacking reference intervals and insufficient clinical data. Therefore, future research activities should focus on analytical standardization and exploration of their clinical value. This review provides an overview on established and new vitamin D related biomarkers including their pathophysiological role, preanalytical and analytical aspects, expected values, indications and influencing conditions.

Evaluating the effects of vitamin D Level on airway obstruction in two asthma endotypes in humans and in two mouse models with different intake of vitamin D during early-life

Introduction

Asthma is primarily divided into two categories: type 2 (T2-high) and non-type 2 (T2-low). A relationship between asthma severity and vitamin D deficiency has been identified, but its impact on each asthma endotype remains unknown.

Methods

We clinically examined the influence of vitamin D on patients with T2-high (n = 60) or T2-low asthma (n = 36) compared with controls (n = 40). Serum 25(OH)D levels, inflammatory cytokines and spirometry were measured. Mouse models were then used to further analyze the effects of vitamin D on both asthmatic endotypes. BALB/c mice were fed with vitamin D-deficient (LVD), -sufficient (NVD), or -supplemented diets (HVD) throughout lactation and offspring followed the same diet after weaning. Offspring were sensitized/challenged with ovalbumin (OVA) to establish "T2-high" asthma or OVA combined with ozone exposure (OVA + ozone) to induce "T2-low" asthma. Spirometry and serum, bronchoalveolar lavage fluid (BALF), and lung tissues were analyzed.

Results

Serum 25(OH)D levels were decreased in asthmatic patients compared with controls. Patients with vitamin D deficiency (Lo) had varying degrees of elevation of the pro-inflammatory cytokines IL-5, IL-6, and IL-17A, decreased expression of the anti-inflammatory cytokine IL-10, and altered forced expiratory volume in the first second as a percentage of predicted value (FEV₁%pred) in both asthmatic endotypes. Vitamin D status had a stronger correlation with FEV₁%pred in T2-low asthma than T2-high asthma, and 25(OH)D level was only positively linked to maximal mid-expiratory flow as a percentage of predicted value (MMEF%pred) in the T2-low group. Inflammation, hyperresponsiveness, and airway resistance (R_L) was increased in both asthma models compared with controls while vitamin D deficiency further increased airway inflammation and airway obstruction. These findings were particularly prominent in T2-low asthma.

Discussion

The potential function and mechanisms of vitamin D and both asthma endotypes should be studied individually, and further analysis of the potential signaling pathways involved with vitamin D on T2-low asthma is warranted.

Vitamin D-induced hypercalcaemia and acute kidney injury in sarcoidosis

Vitamin D deficiency is relatively common, and its management in patients with sarcoidosis is challenging due to the risk of hypercalcaemia. Our patient had an autologous stem cell transplant for multiple sclerosis and was given high-dose vitamin D concurrently with immunosuppressive therapy. The patient subsequently presented with symptomatic hypercalcaemia and an acute kidney injury. A clinical and biochemical recovery was reached by withdrawing vitamin D and administering intravenous fluids. Interestingly, new evidence suggests that activated vitamin D can actually dampen the inflammatory process in sarcoidosis, and this was reflected in a reduction of our patient's serological markers of sarcoidosis activity. One large study found no significant risk of hypercalcaemia when low doses of vitamin D were used in sarcoidosis. Where indicated, and until clear guidelines are established, we suggest using low doses of vitamin D with cautious monitoring of calcium and renal function.

Dietary calcium intake in Brazilian preschoolers and schoolchhildren: review of the literature

Objective:

The objective of this study was to map and synthesize evidence on the adequacy of dietary calcium intake and dairy products in Brazilian preschoolers and schoolchildren.

Data source:

Evidence searches were performed in the MEDLINE (via PubMed) and Latin American and Caribbean Health Sciences Literature (LILACS; via BVS) databases, with no restriction on date or language of publication. Experimental or observational studies that evaluated healthy Brazilian children between 2 and 12 incomplete years old were included.

Data synthesis:

A total of 18 studies were included. Seven of 11 studies of 11 studies (63.6%) identified mean values of dietary calcium intake below the age recommendation, especially in schoolchildren, with the progression of the age group. Among preschoolers, studies with direct weighing of food showed higher mean values of dietary calcium ingested compared to those with dietary recall. Children attending public daycare centers on a part-time basis tended to have inadequate calcium intake. The consumption of milk and dairy products was lower among older children, especially schoolchildren.

Conclusions:

Inadequate dietary calcium intake seems to be prevalent in Brazil during childhood, especially among schoolchildren. Therefore, the evaluation of milk and dairy products intake must be considered in order to desgn appropriate corrective actions.

Plasma parathyroid hormone response to vitamin D3 supplementation among women of reproductive age: A randomized double-blind placebo-control trial

While vitamin D inadequacy occurs worldwide, there is a lack of consensus internationally on the optimum plasma levels of 25(OH)D to maximally suppress the level of parathyroid hormone toward reducing bone loss. This study aimed to investigate the response of intact parathyroid hormone (iPTH) to vitamin D3 supplementation among Malaysian women of reproductive age in a randomised double-blind placebo-control trial [NMRR-15-479-25680]. A total of 106 women who fulfilled the study inclusion criteria were randomly assigned to receive daily one of these three supplement doses (i) 600 IU vitamin D3 + 500 mg calcium; (ii) 1200 IU vitamin D3 + 500 mg calcium; or (iii) 4000 IU vitamin D3 + 500 mg calcium. The placebo group received daily 500 mg calcium. The outcome examined was change in plasma iPTH concentration in response to daily vitamin D3 supplementation for 16 weeks. Fasting blood sample was obtained at baseline and post-supplementation. A total of 78 subjects (73.6%) completed the intervention. None of the supplementation groups brought about any detectable suppression of iPTH concentration post-supplementation. Vitamin D3 supplementation resulted in overall increase in plasma 25(OH)D levels, but only the 4000 IU/day group showed a significant dose effect post-supplementation (mean 49.7 ± 26.5 nmol/L) compared to placebo (29.3 ± 13.3 nmol/L). The lack of iPTH suppression is attributed to high prevalence of vitamin D insufficiency at baseline and the supplementation regimen was inadequate to raise the 25(OH)D level to cause PTH suppression. Inadequate calcium intake of the participants was also a likely contributing factor to the result. As prolonged vitamin D insufficiency and hypocalcaemia could lead to a compensatory rise in PTH resulting in accelerated bone loss, as well as posing increasing risks of non-skeletal morbidities, further clinical trials with an adequately powered sample size should be undertaken over an appropriate study duration to verify the results obtained in this study.

Position Statement: Vitamin D Intake to Prevent Osteoporosis and Fracture in Adults

Adequate vitamin D status is essential for bone health. New randomized controlled trials investigating the effect of vitamin D supplementation on bone health have recently been published. This position statement updates and expands on the previous 2015 position statement of the Korean Society for Bone and Mineral Research on the adequate vitamin D status for healthy older adults (age ≥ 70 years) and those at high risk of osteoporosis and fracture (adults on osteoporosis medications) to maintain serum 25-hydroxy-vitamin D (25[OH]D) levels ≥ 20 ng/mL but < 50 ng/mL. A serum 25(OH)D level of 30 ng/mL may be beneficial for those on anti-resorptives. Vitamin D can be obtained from ultraviolet light exposure and diet. To reach the target vitamin D status through intake, adults must consume at least 400 IU/day to reach 20 ng/mL and 800 to 1,000 IU/day to reach 30 ng/mL. Foods familiar to the Korean diet that are high in vitamin D content or consumed frequently enough to positively impact vitamin D status are introduced in addition to the amount required to help reach one's target vitamin D status.

Changes in Metabolic Parameters in Patients with Diabetic Kidney Disease Depending on the Status of D3

BACKGROUND

Type 2 diabetes is a metabolic disease characterized by hyperglycemia as a result of insulin resistance and decreased insulin secretion. A relatively large number of patients with this type of diabetes have abdominal obesity, which also affects insulin resistance development. Chronic hyperglycemia can lead to damage and dysfunction of various organs, and a striking example is diabetic nephropathy. Diabetic nephropathy is a specific kind of kidney damage that occurs due to complications of diabetes and is accompanied by the formation of diffuse or nodular glomerulosclerosis, which can lead to terminal renal failure and requires immediate substitution through renal therapy or renal transplantation. Diabetic nephropathy is diagnosed with albuminuria and a decrease in the rate of glomerular filtration.

METHODS

This review was based on a literature search for the most important evidence of vitamin D as a possible method of prevention for obesity, type 2 diabetes, and diabetic nephropathy. Collected published articles were summarized according to their overall themes.

RESULTS

In this review, we considered vitamin D as a possible method of treatment for type 2 diabetes, as well as its complications, including diabetic nephropathy.

CONCLUSION

Studies show that vitamin D inhibits the renin-angiotensin-aldosterone system, resulting in improved renal function in diabetic nephropathy. Vitamin D also has antiinflammatory, antiproliferative, and anti-metastatic effects, which improve endothelial function.

Pivotal role of vitamin D in mitochondrial health, cardiac function, and human reproduction

Vitamin D, a secosteroid hormone, appears to have significant beneficial effects on various physiological systems, including the musculoskeletal system. Vitamin D assists in the regulation of numerous critical biological functions and physiological processes in humans, including inflammation, oxidative stress, and mitochondrial respiration, and is also linked to cardiac diseases. It is also reported that vitamin D plays a central role in molecular and cellular mechanisms, which reduce oxidative stress, and tissue damage and regulate cellular health. On the other side, hypovitaminosis D reduces mitochondrial activity and increases oxidative stress and inflammation in the body. Hypervitaminosis D increases the prevalence and severity of cellular damage. It has also been reported that vitamin D is involved in many functions of the reproductive system in human and critically play an important role in the reproductive tissues of women and men. Its role is very well defined, starting from female menarche to menopause, pregnancy, and lactation, and finally in male fertility. Hence, the appropriate amount of vitamin D is necessary to maintain the normal function of cell organelles. Based on recent studies, it is understood that vitamin D is involved in the biological activities of mitochondria in cells, especially in cardiomyocytes. In this review, we emphasized the role of vitamin D in mitochondrial respiration, which could significantly influence heart health and human reproduction.

Impact of vitamin D on maternal and fetal health: A review

The role of vitamin D in improving maternal health and reducing the risk of developmental disorders in fetus has been an important domain of research since the past few years. Vitamin D, owing to its immunomodulatory, anti‐inflammatory, developmental roles, and regulating calcium homeostasis, is predicted to have a significant influence on maternal and fetal health status. Several observational studies and clinical trials, determining the impact of vitamin D on gestational diabetes, C‐section, postpartum depression, pre‐eclampsia, miscarriages, and preterm delivery, have been elaborated in this review. In addition, fetal birth defects including neurological development, reduced birth weight, respiratory infections, bone development, and altered anthropometrics have also been summarized with available evidences. Other important mechanisms related to the roles of vitamin D in the body are also explained. Furthermore, recent studies determining the effect of vitamin D at genetic level will also help in understanding and future design of research in the area of maternal and fetal health.

Vitamin D Intake and Factors Associated With Self-Reported Vitamin D Deficiency Among US Adults: A 2021 Cross-Sectional Study

Vitamin D deficiency is a global issue that may be attributed to various factors such as dietary habits, sun exposure, age, race and chronic conditions. The purpose of this study was to determine the relationship between vitamin D intake from food/supplements and factors that may be associated with self-reported vitamin D deficiency among US adults. A cross-sectional online study was conducted among 1,637 adults using a 38-item questionnaire. Frequency counts and percentages were tabulated and a multiple linear regression was performed. Statistical significance was determined at p &lt; 0.05. Participants (n = 554, 33.8%) were considered vitamin D deficient and consumed an average of 347.05 ± 307.8 IUs of vitamin D through foods/beverages. The multivariate linear regression showed no statistically significant difference with vitamin D intake from foods/beverages on vitamin D deficiency status. Significant positive correlations were seen with vitamin D deficiency status and certain chronic conditions such as chronic kidney disease (p = 0.04), depression (p &lt; 0.001), diabetes (p = 0.02), and vitamin D supplement use (p &lt; 0.001). Significant negative correlations were observed with vitamin D deficiency status and age (p = 0.01) and sun exposure (p &lt; 0.001). Future focus should be on educating individuals about factors associated with vitamin D to reduce the prevalence of vitamin D deficiency.

Clinical Practice in the Prevention, Diagnosis and Treatment of Vitamin D Deficiency: A Central and Eastern European Expert Consensus Statement

Vitamin D deficiency has a high worldwide prevalence, but actions to improve this public health problem are challenged by the heterogeneity of nutritional and clinical vitamin D guidelines, with respect to the diagnosis and treatment of vitamin D deficiency. We aimed to address this issue by providing respective recommendations for adults, developed by a European expert panel, using the Delphi method to reach consensus. Increasing the awareness of vitamin D deficiency and efforts to harmonize vitamin D guidelines should be pursued. We argue against a general screening for vitamin D deficiency but suggest 25-hydroxyvitamin D (25(OH)D) testing in certain risk groups. We recommend a vitamin D supplementation dose of 800 to 2000 international units (IU) per day for adults who want to ensure a sufficient vitamin D status. These doses are also recommended for the treatment of vitamin D deficiency, but higher vitamin D doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment if a rapid correction of vitamin D deficiency is clinically indicated before continuing, with a maintenance dose of 800 to 2000 IU per day. Treatment success may be evaluated after at least 6 to 12 weeks in certain risk groups (e.g., patients with malabsorption syndromes) by measurement of serum 25(OH)D, with the aim to target concentrations of 30 to 50 ng/mL (75 to 125 nmol/L).

Association between 25-hydroxyvitamin D levels and COVID-19 severity

Background and aims

Despite reports on the impact of vitamin D status on coronavirus disease 2019 (COVID-19) severity, the association between low vitamin D status and severe COVID-19 remains unclear. Moreover, researchers have not determined the aforementioned association in Japanese patients. This study aimed to investigate the association between 25-hydroxyvitamin D [25(OH)D] levels and COVID-19 severity in Japanese patients.

Methods

This retrospective observational study included 117 consecutive patients with COVID-19 admitted to the Kobe City Medical Center General Hospital between October 01, 2020, and January 31, 2021. We measured the serum 25(OH)D levels using blood specimens collected within 5 days of hospital admission using liquid chromatography-tandem mass spectrometry.

Results

There were 21 (17.9%), 73 (62.4%), 19 (16.2%) and 4 (3.4%) patients with severe deficiency (<10 ng/mL), deficiency (10–<20 ng/mL), insufficiency (20–<30 ng/mL), and sufficiency (≥30 ng/mL) of vitamin D, respectively. In univariate logistic regression analyses, lower serum 25(OH)D levels [odds ratio (OR) 1.18 per 1 ng/mL decrease, 95% confidence interval (CI) 1.04–1.33, p = 0.007] were significantly associated with invasive mechanical ventilation (IMV) or death. In a multivariate logistic regression analysis, low serum 25(OH)D levels [OR 1.22 per 1 ng/mL decrease, 95% CI 1.06–1.40, p = 0.005] were significantly associated with IMV or death. The cut-off value of serum 25(OH)D levels was 10.4 ng/mL, calculated by the receiver operating characteristic curve to detect the requirement for IMV or death.

Conclusions

To the best of our knowledge, this is the first study to assess the association between vitamin D status and COVID-19 severity in Japanese patients. Low serum 25(OH)D level was detected as an independent risk factor for severe COVID-19 among Japanese patients.

Vitamin D and its possible relationship to neuroprotection in COVID-19: evidence in the literature

Abstract:

Vitamin D is a hormone involved in the regulation of important biological processes such as signal transduction, immune response, metabolic regulation and also in the nervous and vascular systems. To date, coronavirus disease 2019 (COVID-19) infection does not have a specific treatment, however various drugs have been proposed, including those that attenuate the intense inflammatory response and recently the use of vitamin D, in clinical trials, as part of the treatment of COVID-19 has provided promising results. It has been observed in some clinical studies that the use of cholecalciferol (vitamin D3) and its two metabolites the circulating form, calcidiol or calcifediol (25-hydroxycalciferol, 25-(OH)-D) and the active form, calcitriol (1,25-(OH)2-D), in different doses, improve the clinical manifestations, prognosis and survival of patients infected with COVID-19 probably because of its anti-inflammatory, antiviral and lung-protective action. In relation to the central nervous system (CNS) it has been shown, in clinical studies, that vitamin D is beneficial in some neurological and psychiatric conditions because of its anti-inflammatory and antioxidant properties, modulation of neurotransmitters actions, regulation of calcium homeostasis between other mechanisms. It has been showed that COVID-19 infection induces CNS complications such as headache, anosmia, ageusia, neuropathy, encephalitis, stroke, thrombosis, cerebral hemorrhages, cytotoxic lesions and psychiatric conditions and it has been proposed that the use of dietary supplements, as vitamin and minerals, can be adjuvants in this disease. In this review the evidence of possible role of vitamin D, and its metabolites, as protector against the neurological manifestations of COVID-19 was summarized.

Immunonutrients involved in the regulation of the inflammatory and oxidative processes: implication for gamete competence

Purpose

The purpose of this umbrella review is to bring together the most recent reviews concerning the role of immunonutrients for male and female infertility.

Methods

Regarding immunonutrients and fertility, the authors have analyzed reviews, systematic reviews, and meta-analyses published between 2011 and June 2021. All reviews on animal or in vitro studies were excluded. Relevant keywords to term micronutrients were analyzed alone or in association with other terms such as “gamete competence,” “male OR female fertility,” “male OR female infertility,” “fertile, “folliculogenesis,” “spermatogenesis,” “immunomodulation,” “immune system,” “oxidative stress.”

Results

The primary research has included 108 results, and after screening by title, abstract. and not topic-related, 41 studies have been included by full texts. The results show the molecular mechanisms and the immunonutrients related impact on gamete formation, development. and competence. In particular, this review focused on arginine, glutamine, vitamin C, vitamin D, vitamin E, omega-3, selenium, and zinc.

Conclusions

Inflammation and oxidative stress significantly impact human reproduction. For this reason, immunonutrients may play an important role in the treatment of infertile patients. However, due to the lack of consistent clinical trials, their application is limited. Therefore, the development of clinical trials is necessary to define the correct supplementation, in case of deficiency.

25-Hydroxyvitamin D as a biomarker of vitamin D status in plaque psoriasis and other dermatological diseases: a cross-sectional study

BACKGROUND

Hypovitaminosis D is a public health problem associated with several chronic inflammatory and immunological diseases, including psoriasis.

OBJECTIVES

This study aimed to determine the prevalence of hypovitaminosis D in patients with plaque psoriasis. A comparison was made between vitamin D levels in patients with psoriasis and those with other non-inflammatory dermatoses without photosensitivity. In addition, it evaluated the effects of the patients' Fitzpatrick skin phototype and the season of the year on the serum levels of vitamin D.

DESIGN AND SETTINGS

A retrospective cross-sectional study was conducted at an outpatient clinic in a university center in Juiz de Fora (MG), Brazil.

METHODS

A review of dermatology patients' demographic data, including skin phototype and serum levels of 25-hydroxyvitamin D [25(OH)D], over 12 months in 2016.

RESULTS

This study included 554 patients: 300 patients allocated to the plaque psoriasis group and 254 control patients with other dermatological diseases. Regarding the season of the year, 229, 132, 62, and 131 participants were evaluated in summer, autumn, winter, and spring, respectively. As for the skin phototype, 397, 139, and 18 patients had phototypes III, IV, and V, respectively. The serum levels of 25(OH)D were significantly lower in the psoriasis group (24.91 ± 7.16 ng/mL) than in the control group (30.37 ± 8.14 ng/mL).

CONCLUSIONS

Hypovitaminosis D (< 30 ng/mL) was present in 76.66% of patients with psoriasis versus 53.94% of control patients. Vitamin D deficiency (< 20 ng/mL) was observed in 25% of the patients with psoriasis versus 8.66% in the control group (P < 0.001). The season and patient's skin phototype were independent predictors of serum vitamin D levels.

Vitamin D [25(OH)D] metabolites and epimers in obese subject: Interaction and correlations with adverse metabolic health risk factors

BACKGROUND

Although both vitamin D deficiency and obesity are highly prevalent in the UAE, the role of vitamin D metabolites in mediating obesity-related adverse health effects is not clear. We aimed to assess the role of vitamin D metabolites as potential mediators in the association between obesity, inflammation and metabolic risk factors.

METHODS

277 participants who were part of a randomized controlled trial had their assessment that included clinical, anthropometric and physical activity data at baseline and at 6 months. Blood and urine samples were taken for measurements of serum 25(OH)D, 25(OH)D metabolites including 25(OH)D3), 25(OH)D2), 1,25(OH)2D3, 3-Epi-D3), metabolic and inflammatory markers and related biochemical variables. Multiple regression analysis used to assess the role of 25(OH)D metabolites in mediating the effect of increasing body mass index (BMI) on inflammation and metabolic risk factors.

RESULTS

Overall, 277 participants with complete 6 months follow up with a mean (±SD) age of 41 ± 12 and 204 (74%) female were included in the study. Blood pressure, inflammatory, metabolic and lipid profile markers significantly increased in overweight and obese subjects compared to subjects with normal BMI both at baseline and at 6 months (p < 0.05). 25(OH)D revealed significant association with age, gender, HbA1c and type 2 diabetes (p < 0.05). No statistically significant changes in any of 25(OH)D metabolites assessed. Multivariate analysis revealed significant and independent associations between BMI and important inflammatory and metabolic risk factors (p < 0.05). No similar association observed with 25(OH)D metabolites.

CONCLUSION

Although we found significant association between 25(OH)D and prevalence of type 2 diabetes, we found no evidence however to support a role of 25(OH)D metabolites in mediating the effect of BMI on inflammatory or metabolic risk factors.

Characteristics Associated with Acute-Phase Response following First Zoledronic Acid Infusion in Brazilian Population with Osteoporosis

We aimed to evaluate characteristics associated with acute-phase response (APR) following first zoledronic acid infusion in a Brazilian cohort. This retrospective cohort study enrolled all adults with osteoporosis who underwent a first zoledronic acid infusion at our centre between June 2015 and June 2019. Clinical demographics (age, sex, diabetes, smoking, body mass index, and previous oral bisphosphonate use) and laboratory data (calcium, parathyroid hormone, renal function, and serum 25-hydroxyvitamin D and carboxy-terminal crosslinked telopeptide of type 1 collagen [CTX], both before and after infusion) were compared between patients with and without APR. We evaluated association magnitude between the presence of APR and clinical variables through logistic regression. This study enrolled 400 patients (women, 80%). APR was observed in 24.5% (n = 98) of patients. The mean symptom duration in days was 3.5 ± 2.8. Patients with APR were younger (67 ± 12 vs. 71 ± 11 years; p=0.001), used oral bisphosphonates less frequently (34% × 50%; p=0.005), and had greater baseline CTX (0.535 ng/mL [0.375, 0.697] × 0.430 [0.249, 0.681]; p=0.03) and ΔCTX (-69 [-76; -50] × -54 [-72; -23]; p=0.002) than those without APR. The other variables were similar between the groups. Only ΔCTX was associated (OR, 0.62; 95% CI 0.41-0.98) with APR after accounting for age and bisphosphonate use. APR occurred in 24.5% of the cohort. Younger age and absence of prior oral bisphosphonate use were associated with APR following first zoledronic acid infusion. APR was associated with ΔCTX (but no other variables) after adjusting for these factors.

The role of vitamin D deficiency and elevated inflammatory biomarkers as risk factors for the progression of diabetic nephropathy in patients with type 2 diabetes mellitus

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease worldwide. Albuminuria is the most sensitive marker for the early recognition of DN. Therefore, we aimed to study the risk factors of albuminuria as a marker of DN among diabetic patients. The study included 41 patients with type 2 diabetes mellitus (T2DM), 50 type 2 diabetic nephropathy (T2DN) patients with macroalbuminuria, 43 T2DN patients with microalbuminuria and 38 healthy controls. Logistic regression was used to detect the most significant risk factors for albuminuria. A high statistically significant difference was found between the groups regarding age, sex, body mass index (BMI), diabetes mellitus (DM) duration, glucose, glycated haemoglobin (HbA1c), creatinine, glomerular filtration rate (GFR), lipid profile, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), the albumin–creatinine ratio (ACR), vitamin D, total parathyroid hormone (PTH), urea, total calcium and chemerin (p < 0.001). It was found that the duration of DM, BMI, glucose, GFR, total cholesterol (TC), low-density lipoprotein (LDL), TNF-α, IL-6, CRP, ACR, vitamin D, PTH and chemerin are significant albuminuria risk factors in DN. Vitamin D deficiency and associated inflammatory mediators such as chemerin, TNF-α, IL-6 and CRP are the most essential risk factors for albuminuria in T2DM patients.

Early Evidence Indicates Vitamin D Improves Symptoms of Irritable Bowel Syndrome: Nursing Implications and Future Research Opportunities

Irritable bowel syndrome (IBS) affects approximately 11.2% of the population. Yet, full understanding of its etiology and optimal treatment remains elusive. Understanding of the underlying pathophysiology of IBS has been limited. However, research is beginning to identify the cause as multifactorial (e.g., low-grade local mucosal inflammation, systemic immune activation, altered intestinal permeability, intestinal hypersensitivity, altered central nervous system processing, changes in intestinal microbiota). Understanding of the role of vitamin D in intestinal inflammation, immunity, and gastrointestinal conditions is increasing but is not yet fully understood. Growing evidence has linked vitamin D deficiency with a variety of gastrointestinal disorders, including inflammatory bowel disease, diverticulitis, colorectal cancer, and IBS. Several studies have demonstrated that individuals with IBS are more likely to have vitamin D deficiency than healthy controls. Recent vitamin D supplementation studies have shown improvement in quality of life and reduction in IBS symptoms (including abdominal pain, distention, flatulence, constipation, and visceral sensitivity) but the mechanism remains unclear. Nurses are well positioned to educate patients about the importance of sufficient vitamin D for overall health in individuals with IBS as well as participate in well-designed therapeutic studies to explore whether enhanced vitamin D status will ultimately help treat IBS more effectively.

Determinants of circulating 25-hydroxyvitamin D concentration and its association with musculoskeletal health in midlife: Findings from the Hertfordshire Cohort Study

INTRODUCTION

Several studies have reported the importance of vitamin D status to musculoskeletal health in populations of older adults. Here we report relationships between circulating serum 25(OH)D and musculoskeletal health in a community cohort of UK adults in midlife and investigate whether environmental (dietary intake, use of supplements) and/or genetic factors (4 SNPs previously related to vitamin D status) play more significant roles in determining vitamin D status in this population.

METHODS

Participants were recruited from the Hertfordshire Cohort Study, an established longitudinal cohort study of community dwelling adults and were seen at baseline and follow up 9-12 years later. Lumbar spine and total femur BMD were measured at baseline using a Hologic QDR 4500 instrument. Osteoarthritis (OA) was defined by radiographs of the knees graded according to Kellgren & Lawrence at both time points. Serum 25(OH)D concentrations were measured using a DiaSorin Liaison chemiluminescent assay. Genotyping of 4 SNPs previously associated with 25(OH)D values were assessed: (rs12785878 (DHCR7), rs10741657 (CYP2R1) and rs6013897 (CYP24A1)) and a fourth SNP (rs4588), described as "a near-perfect proxy (i.e. substitute) for rs2282679 on the GC gene".

RESULTS

820 subjects (397 men, 423 women) participated at baseline, and 339 of these 820 subjects (164 men; 175 women) participated in a follow up study of OA progression. The median (IQR) age of participants at baseline was 64.0 (61.8-66.5) and 65.5 (63.3-67.6) for men and women respectively. Median circulating levels of 25(OH)D were 44.6 (35.0-63.0) nmol/L and 41.3 (29.8-53.5) nmol/L in men and women respectively. Circulating 25(OH)D was strongly associated with season of blood testing (p < 0.001). The greatest variance in a model of vitamin D status that included the four SNPs measured, season, and whether participants reported taking vitamin D supplements was explained by season of assay (17.9% men; 15.8% women). Higher femoral neck BMD was observed in men with higher baseline vitamin D status, after adjustment for age, season, BMI, smoker status, alcohol consumption, physical activity and social class (p = 0.01). Associations between 25(OH)D and BMD in women were not statistically significant in this population. There were no associations between circulating 25(OH)D and radiographic knee OA at either time point after adjustment for confounders and for duration of follow-up.

CONCLUSION

Circulating 25(OH)D levels were generally lower than is recommended in community dwelling adults in midlife, with marked seasonal variation observed, but relationships with reported vitamin D supplementation were weaker. Circulating 25(OH)D was directly associated with hip BMD in men but relationships with BMD in women and radiographic OA were not seen in this sample.