Vitamin D supplementation guidelines

Sarcopenia and Vitamin D Deficiency in Patients with Crohn's Disease: Pathological Conditions That Should Be Linked Together

Sarcopenia is a prevalent condition in patients with Crohn’s disease (CD), representing an independent predictor factor for the development of major postoperative complications. Thus, a proper assessment of the muscle strength, by using different validated tools, should be deemed an important step of the clinical management of these patients. Patients with CD are frequently malnourished, presenting a high prevalence of different macro- and micro-nutrient deficiencies, including that of vitamin D. The available published studies indicate that vitamin D is involved in the regulation of proliferation, differentiation, and regeneration of muscle cells. The relationship between vitamin D deficiency and sarcopenia has been extensively studied in other populations, with interesting evidence in regards to a potential role of vitamin D supplementation as a means to prevent and treat sarcopenia. The aim of this review was to find studies that linked together these pathological conditions.

Vitamin D supplementation does not enhance resistance training-induced gains in muscle strength and lean body mass in vitamin D deficient young men

PURPOSE

Vitamin D (Vit-D) supplementation has been shown to increased muscle strength in young adults. It remains unclear if Vit-D supplementation enhances the efficacy of resistance training (RT). This study tested the hypothesis that Vit-D supplementation would enhance the RT-induced increases in muscle strength and lean body mass (LBM) in Vit-D deficient young men.

METHODS

Thirty-nine men (baseline serum 25(OH)D < 50 nmol L^‒1) were quasi-randomly assigned to one of the two groups that performed a 12-week supervised RT program concomitant with either Vit-D (8000 IU daily; VD) or placebo (PLC) supplementation.

RESULTS

During 12-week RT, energy and nutrient (except Vit-D) intake and training loads did not differ in the two groups. Serum 25(OH)D levels increased from 36.3 ± 9.2 to 142.4 ± 21.9 nmol L^‒1 (P < 0.05) in VD group and remained unchanged between 36.3 ± 8.9 and 29.4 ± 6.6 nmol L^‒1 (P > 0.05) in PLC group. Muscle strength (1-repetition maximum) increased (P < 0.05) to an equal extent in the two groups in 5 exercises performed on RT equipment, whereas strength gains in chest press and seated row were greater (P < 0.05) in PLC compared to VD group. Total and regional LBM (measured by DXA scan) increased (P < 0.05) equally in the two groups. Android fat mass decreased (P < 0.05) in VD group only.

CONCLUSION

Vit-D supplementation does not enhance the efficacy of RT in terms of muscle strength and LBM gains in Vit-D deficient young healthy men.

Effect of Vitamin D Status on Vascular Function of the Aorta in a Rat Model of PCOS

Polycystic ovary syndrome (PCOS) is associated with elevated cardiovascular risk. Early vascular dysfunction may lead to the development of cardiovascular disease in PCOS. Vitamin D deficiency (VDD) is a common comorbidity of PCOS that contributes to the pathogenesis of the disease and its complications. Both PCOS and VDD are accompanied by increased oxidative stress that may be involved in the arising vascular dysfunction. We aimed to investigate the role of vitamin D status on aortic function. PCOS was induced by an 8-week-long transdermal testosterone treatment of female rats, and low and adequate vitamin D status was achieved by dietary means. Contraction and relaxation abilities of isolated aortic segments were measured by myograph. Resorcin-fuchsin staining and immunohistochemical labeling of 3-nitrotyrosine were performed. No difference was shown in the norepinephrine-induced contraction of the aortas of different groups, whereas we detected reduced acetylcholine- and insulin-evoked relaxation in VDD groups. A lower level of resorcin-fuchsin staining and elevated 3-nitrotyrosine immunostaining was observed in VDD. In our study, we demonstrated early endothelial dysfunction in VDD PCOS rat model. Vitamin D supplementation could prevent vascular disturbances, while VDD itself damaged endothelium-dependent vasorelaxation and induced nitrative stress.

Association between Vitamin D Supplements, Oxidative Stress Biomarkers, and Hyperbaric Therapy in Patients with Sudden Sensorineural Hearing Loss

The effect of vitamin D supplementation to patients with sudden sensorineural hearing loss (SSNHL), treated with hyperbaric oxygen (HBO) therapy, on the markers of the oxidant-antioxidant equilibrium was investigated. Patients were divided into two groups: those who did and did not receive vitamin D (cholecalciferol at 4000 IU/24 h). Concentrations of the following compounds, thiobarbituric acid reactive substances (TBARS), malondialdehyde (MDA), conjugated dienes (CD) in plasma and erythrocytes and activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in erythrocytes, were determined. Haemoglobin (HGB) and haematocrit (HCT) were measured. Blood for analyses was collected from the basilic vein at three time points: before the first HBO procedure, up to 5 min after the first procedure, and after 14 procedures. No statistically significant differences in parameters tested were found between patients who did and did not receive vitamin D. In patients without supplementation, an increase of 53.2% (P ≤ 0.05) in erythrocyte TBARS was observed after the first HBO treatment. In patients receiving vitamin D, a reduction of 27.6% (P ≤ 0.05) was observed in erythrocyte MDA after 14 HBO treatments vs. that after the first treatment. In both groups, a decrease of 33.3% in plasma CD was observed after 14 treatments vs. that after the first treatment (P ≤ 0.05 and P ≤ 0.01, respectively). No statistically significant changes were observed in the erythrocyte SOD, GPx, and CAT activities and in HCT. A reduction of HGB concentration of 10.9% (P ≤ 0.05) was demonstrated in nonsupplemented patients after 14 treatments compared with baseline. The results confirm that the effect of HBO therapy on oxidative stress markers is inconclusive and complex. Repeated HBO procedures can induce adaptive changes which protect against disruption of the oxidant-antioxidant equilibrium. It is possible that vitamin D supplementation inhibits the process of lipid peroxidation in erythrocytes.

Vitamin D and COVID-19: It is time to act

Vitamin D (VitD) deficiency is considered a global problem and might be associated with increased susceptibility to COVID-19 illness. In the light of COVID-19 pandemic, VitD might be a promising agent for fighting the SARS-CoV-2, since VitD is involved in various pathophysiological mechanisms that occur during COVID-19 infection. High-dose VitD supplementation, particularly for risk groups, could be recommended to achieve and maintain optimal (range 40-60 ng/mL) serum 25-hydroxy vitamin D levels (marker of VitD status) both for COVID-19 prevention and treatment.

Proximal muscle strength as a predictor of vitamin D insufficiency in elderly

OBJECTIVES

This study aims to evaluate the association of serum vitamin D level with proximal muscle strength, tone, elasticity, and stiffness in elderly.

PATIENTS AND METHODS

Between September 2017 and January 2018, a total of 109 participants (21 males, 88 females; mean age: 71.2±4.6 years; range, 65 to 85 years) were included in the study. The proximal muscle strength was evaluated by MicroFET® 3 device. The muscle tone, elasticity, and stiffness were measured using the MyotonPRO® digital palpation device. Serum 25-hydroxyvitamin D [25(OH)D] level was tested by high-performance liquid chromatography. A receiver operating characteristic (ROC) curve was performed to evaluate the potential role of MicroFET® 3-measured proximal muscle strength in the quantification of vitamin D status.

RESULTS

Vitamin D sufficient participants had a higher proximal muscle strength (p<0.001). Quadriceps and hamstring elasticity at the non-dominant site were significantly higher in vitamin D sufficient group (p<0.05). The ROC analysis indicated that the deltoid muscle strength had the potential of determining vitamin D insufficiency with moderate accuracy (area under the curve=0.744; 95% confidence interval: 0.643-0.845; p<0.001).

CONCLUSION

Proximal muscle strength, elasticity, and physical performance are associated with vitamin D status. Proximal muscle strength measured by a hand-held dynamometer can be used as a predictor of hypovitaminosis D in elderly.

Vitamin D levels of the healthy infants using oral spray or drop form of vitamin D supplement in the first year of life

OBJECTIVE:

Vitamin D (VD) deficiency is a common problem worldwide, especially in pregnant women and newborns. Regular administration of VD supplements has been recommended worldwide since 2010. Recently, a new formulation providing VD supplementation in the form of a spray which is absorbed through the buccal mucosa has been introduced, but there is very little information in the literature about the effectiveness of it, especially in children. Therefore, in our study, we aim to investigate whether there was a difference in VD levels at one year of age infants who have started oral vitamin D supplements (400 IU/day) as spray or drop form in the neonatal period and have used it regularly during the first year of life.

METHODS:

In our retrospective study, the medical records of 243 healthy infants at one year of age who were followed up regularly in the first year of life in our well-child follow-up clinic were evaluated. The infants who had congenital anomalies, chronic diseases, and those using irregular vitamin D supplements were excluded from this study.

RESULTS:

The findings showed that the spray form of VD was used in 136 babies (56.0%) in the study group and the drop form was used in 107 (44.0%) of them. VD deficiency (defined as 25 [OH] D level <20 ng/ml) was 33.3% (n=81). VD levels were 24 ng/ml (8–109 ng/ml) and 21 ng/ml (7–65 ng/ml) in the infants using spray and drop form, respectively. The difference between the two forms of VD supplementation regarding 25 (OH) D levels was significant (p=0.010); VD levels were higher in the infants using the spray form.

CONCLUSION:

Our study findings suggest that the infants using oral spray form have higher VD levels compared to oral drop form. Concerning VD levels, the spray form may be preferred as a suitable alternative to the drop form, and the spray form may provide regular and easy use in children.

Role of natural products in alleviation of rheumatoid arthritis-A review

Rheumatoid arthritis (RHA) is one of the most prevalent complex, chronic, inflammatory diseases, manifested by elevated oxidative stress and inflammatory biomarkers. Prolonged administration of NSAIDs, steroids, and DMARDs, used in the treatment of RHA, is associated with deleterious side effects. This necessitates the urge of new and safe approaches for RHA management, based on the complementary and alternative system of medicine. Documented evidences have suggested that supplementation with nutritional, dietary, and herbal components; can play a crucial role as an adjuvant, in the alleviation of the RHA symptoms, through their influence on the pathological inflammatory processes. Dietary phenolic compounds, flavonoids, carotenoids, and alkaloids with their ability to modulate prooxidant and pro-inflammatory pathways, have been effective in delaying the arthritic disease progression. Moreover, in scientific explorations, herbs containing phenolic compounds, alkaloids, carotenoids flavonoids, spices such as ginger, turmeric, Ayurvedic formulations, different diets such as Mediterranean diet, vegan diet, beverages, and oils such as sesame oil, rice bran oil, vitamins, and probiotics are proven to modulate the action of inflammatory molecules, involved in RHA pathology. Subsequently, the purpose of this review article is to summarize various in vitro, in vivo, and clinical studies in RHA, which have documented remarkable insights into the anti-inflammatory, antioxidant, analgesic, and immunomodulatory, bone erosion preventing properties of dietary, nutritional, and herbal components with the focus on their molecular level mechanisms involved in RHA. Even though major findings were derived from in vitro studies, several in vivo and clinical studies have established the use of diet, herbal, and nutritional management in RHA treatment. PRACTICAL APPLICATIONS: Thickening of the synovial membrane, bone erosion, and cartilage destruction is known to trigger rheumatoid arthritis causing inflammation and pain in bone joints. Continuous intake of NSAIDs, steroids, and DMARD therapy are associated with detrimental side effects. These side effects can be overcome by the use of dietary, nutritional, and herbal interventions based on the complementary and alternative therapy. This concept portrays the food components and other natural components having the potential to promote health, improve general well-being, and reduce the risk of RHA.

Drug-related problems among older patients: Analysis of 8 years of pharmacist's interventions

OBJECTIVES

To analyse the most frequent DRP over time and pharmacists' interventions made among older patients aged over 75 years old. DRP between older patients and younger patients aged 18 to 74 years and between older patients treated in geriatric wards or not were also compared.

METHODS

A cross-sectional observational study conducted on DRP detected by pharmacists at the university hospital centre of Lyon and prospectively recorded in the Act-IP© database from January 2008 to December 2015.

RESULTS

A total of 56,223 DRP were investigated - 19,056 in older patients and 37,167 in younger patients. A supratherapeutic dosage was mainly reported (22.4% in older patients vs. 19.0% in younger patient) and pharmacists made interventions mostly to adjust dosage (27.3% vs. 24.2%). Physicians' acceptance was significantly lower in older patients (57.1% vs. 64.3%). DRP associated to a drug included a supratherapeutic use of acetaminophen (5.2% vs. 3.8%) and hypnotics (4.0% vs. 1.4%), medication in cardiology used without indication (1.4% vs. 0.2%) and underuse of vitamin D (1.2% vs. 0.1%). Supratherapeutic dosages were more significantly detected with a lower overall physicians' acceptance in older patients treated in general wards.

CONCLUSIONS

This study highlights the specificity of DRP among older patients and encourages health care professionals to remain especially alert regarding older patients treated in general wards. These findings can contribute to define or adjust training needs and quality indicators to improve the daily practices of health care professionals.

Vitamin D: Vitamin or Hormone?

Vitamin D can be obtained from diet, direct sunlight, or supplementation. The most common form is synthesized in the skin after exposure to ultraviolet B radiation. Nevertheless, the thought is that vitamin D is more of a multifunctional hormone or prohormone. This is because vitamin D plays contributes to many processes in the body. Calcitriol has been shown to have enhancing effects on the immune system, the cardiovascular system, the endocrine system, and other metabolic pathways. There is evidence that vitamin D has also a role in depression, pain, and cancer.

Potential immunomodulatory effects of vitamin D in the prevention of severe coronavirus disease 2019: An ally for Latin America (Review)

Currently, the world is under a pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019 (COVID-19). This disease is characterized by a respiratory syndrome that can progress to an acute respiratory distress syndrome. To date, limited effective therapies are available for the prevention or treatment of COVID-19; therefore, it is necessary to propose novel treatment options with immunomodulatory effects. Vitamin D serves functions in bone health and has been recently reported to exert protective effects against respiratory infections. Observational studies have demonstrated an association between vitamin D deficiency and a poor prognosis of COVID-19; this is alarming as vitamin D deficiency is a global health problem. In Latin America, the prevalence of vitamin D deficiency is unknown, and currently, this region is in the top 10 according to the number of confirmed COVID-19 cases. Supplementation with vitamin D may be a useful adjunctive treatment for the prevention of COVID-19 complications. The present review provides an overview of the current knowledge of the potential immunomodulatory effects of vitamin D in the prevention of COVID-19 and sets out vitamin D recommendations for the Latin American population.

Putative role of vitamin D in the mechanism of alcoholism and other addictions - a hypothesis

OBJECTIVE

Vitamin D deficiency may be a clinical problem in patients with addictions. The authors systematically searched for studies addressing vitamin D and addiction and develop a hypothesis which can direct future research of the possible mechanistic role of vitamin D in the process of addiction.

METHODS

Systematic review of the literature found in PubMed and EMBASE followed by narrative review combined with clinical experiences leading to hypotheses for future research.

RESULTS

Only five articles were identified about a role of vitamin D in the pathophysiology of addiction. Their results are in line with a possible influence of vitamin D in dopaminergic transmission. The cerebral vitamin D status depends on the functionality of genetic variants of vitamin D receptor and other involved genes. Routine serum calcidiol levels may not adequately reflect cerebral vitamin D status. Uncertainty exists regarding appropriate calcidiol blood levels and proper dosages for affecting the central nervous system (CNS).

CONCLUSIONS

The putative pathophysiological role of vitamin D in substance abuse has been insufficiently studied which calls to more studies how to measure cerebral vitamin D status in clinical practice. Research is indicated whether vitamin D supplementation should use higher dosages and aim to reach higher calcidiol serum levels. Measuring dopaminergic functioning within the prefrontal cortex as reflected by neuropsychological tests selected as suitable could be a appropriate proxy for the cerebral vitamin D status when studying the pharmacogenomics of this functionality in patients.

A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial of High-Dose, Short-Term Vitamin D Administration in the Prevention of Acute Kidney Injury after Cardiac Surgery

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery is a relatively common complication affecting short- and long-term survival. The renoprotective effect of vitamin D (VitD) has been confirmed in several experimental models. This study was conducted to evaluate the effect of high-dose VitD administration in patients with VitD insufficiency on the incidence of postoperative AKI, the urinary level of tubular biomarkers, and serum anti-inflammatory biomarker after coronary artery bypass graft.

DESIGN AND METHOD

In this randomized double-blind controlled clinical trial, the patients were randomly allocated to either the VitD group (n = 50), receiving 150,000 IU VitD tablets daily for 3 consecutive days before surgery or the control group (n = 61), receiving placebo tablets.

RESULTS

There was no difference in the incidence of postoperative AKI between the groups. Both of the urinary levels of interleukin-18 and kidney injury molecule-1 were significantly increased after the operation (p < 0.001, for both). Also, the serum level of interleukin-10 was increased after 3 days of VitD supplementation (p = 0.001). In comparison with the control group, it remained on a higher level after the operation (p < 0.001) and the next day (p = 0.03). The patients with AKI had more postoperative bleeding and received more blood transfusion.

CONCLUSION

VitD pretreatment was unable to impose any changes in the incidence of AKI and the urinary level of renal biomarkers. However, high-dose administration of VitD may improve the anti-inflammatory state before and after the operation. Further studies are needed to assess the renoprotective effect of VitD on coronary surgery patients.

Effects of Different Vitamin D Supplementation Schemes in Post-Menopausal Women: A Monocentric Open-Label Randomized Study

BACKGROUND

The improvement of muscular strength is a well-known extra-skeletal effect of Vitamin D. The aim of the study was to evaluate the effectiveness of the calcifediol supplementation compared to various cholecalciferol administration schedules in increasing 25(OH)D serum levels and improving muscular function.

METHODS

107 post-menopausal women with hypovitaminosis D were assigned to receive Vitamin D supplementation according to four different regimens: colecalciferol single, monthly, or weekly oral dose and calcifediol weekly oral dose. Serum levels of 25(OH)D and muscular function of lower limbs (Sit-to-Stand test and Timed-Up-and-Go test) were evaluated at baseline and during 6 months follow-up.

RESULTS

Calcifediol and weekly cholecalciferol induced a greater and faster increase of serum 25(OH)D, compared to monthly or single-dose cholecalciferol administration. The 25(OH)D increase was associated with an improvement of muscle function of lower limbs. The larger increase of serum 25(OH)D observed with calcifediol and with weekly cholecalciferol was associated with a concomitant greater improvement of muscle strength.

CONCLUSIONS

Supplementation with calcifediol is more effective and faster compared to cholecalciferol in increasing 25(OH)D serum levels and is associated with a greater improvement of muscular function, thus representing a therapeutic alternative for treatment of hypovitaminosis D.

A Vicious Cycle of Osteosarcopeniain Inflammatory Bowel Diseases-Aetiology, Clinical Implications and Therapeutic Perspectives

Sarcopenia is a disorder characterized by a loss of muscle mass which leads to the reduction of muscle strength and a decrease in the quality and quantity of muscle. It was previously thought that sarcopenia was specific to ageing. However, sarcopenia may affect patients suffering from chronic diseases throughout their entire lives. A decreased mass of muscle and bone is common among patients with inflammatory bowel disease (IBD). Since sarcopenia and osteoporosis are closely linked, they should be diagnosed as mutual consequences of IBD. Additionally, multidirectional treatment of sarcopenia and osteoporosis including nutrition, physical activity, and pharmacotherapy should include both disorders, referred to as osteosarcopenia.

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.

Putative roles of vitamin D in modulating immune response and immunopathology associated with COVID-19

The first incidence of COVID-19 was reported in the Wuhan city of Hubei province in China in late December 2019. Because of failure in timely closing of borders of the affected region, COVID-19 spread across like a wildfire through air travel initiating a pandemic. It is a serious lower respiratory track viral infection caused by highly contagious, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Coronavirus including COVID-19 causing SARS-CoV-2 causes zoonotic diseases and thought to be originated from bats. Since its first incidence, the virus has spread all across the world, causing serious human casualties, economic losses, and disrupting global supply chains. As with SARS-CoV, COVID-19 causing SARS-CoV-2 follows a similar path of airborne infection, but is less lethal and more infectious than SARS and MERS. This review focusses on the pathogenesis of SARS-CoV-2, especially on the dysfunctional immune responses following a cytokine storm in severely affected persons. The mode of entry of SARS-CoV-2 is via the angiotensin converting enzyme 2 (ACE-2) receptors present on the epithelial lining of lungs, gastrointestinal tract, and mucus membranes. Older persons with weaker immune system and associated co-morbidities are more vulnerable to have dysfunctional immune responses, as most of them concomitantly have severe hypovitaminosis D. Consequently, causing severe damage to key organs of the body including lungs and the cardiovascular system. Since, vast majority of persons enters to the intensive care units and died, had severe vitamin D deficiency, thus, this area must be investigated seriously. In addition, this article assesses the role of vitamin D in reducing the risk of COVID-19. Vitamin D is a key regulator of the renin-angiotensin system that is exploited by SARS-CoV-2 for entry into the host cells. Further, vitamin D modulates multiple mechanisms of the immune system to contain the virus that includes dampening the entry and replication of SARS-CoV-2, reduces concentration of pro-inflammatory cytokines and increases levels of anti-inflammatory cytokines, enhances the production of natural antimicrobial peptide and activates defensive cells such as macrophages that could destroy SARS-CoV-2. Thus, this article provides the urgency of needed evidences through large population based randomized controlled trials and ecological studies to evaluate the potential role of vitamin D in COVID-19.

Benefits of vitamin D supplementation to attenuate TBI secondary injury?

Vitamin D supplementation has been shown to improve outcomes for patients suffering from a variety of illnesses such as stroke and cancer. Vitamin D deficiencies have been associated with longer hospital stays, greater severity of symptoms, and death in some complex cases. Due to vitamin D’s burgeoning role in improving patient outcomes, a new sector of research is focusing on the lesser-known implications of vitamin D on health. Traumatic brain injury (TBI) affects approximately 69 million people worldwide per year. Here, we summarize the current scientific understanding of vitamin D dynamics with TBI to elucidate a potential way to lessen the cascade of secondary damage after an initial insult, with the goal of improving overall patient outcomes. Because vitamin D supplementation has been correlated with better outcomes in other pathologies involving immune and inflammatory molecules, it is important to study the potential effect of vitamin D deficiency (VDD) and supplementation on TBI outcomes. Research on vitamin D supplementation in TBI remains in the preliminary stages. There is still much to learn about vitamin D deficiency, dosage, variants of supplementary forms, mechanisms, and its role in TBI.

Vitamin D supplementation: position Statement of the Iberoamerican Society of Osteoporosis and Mineral Metabolism (SIBOMM)

BACKGROUND

Vitamin D (VD) deficiency is a global pandemic that affects more than a third of the population worldwide. The population of Latin America and the Caribbean exceeds 620 million inhabitants with diverse ethnic origins and different latitudes and altitudes, which make comparisons and generalizations difficult.

AIM AND METHOD

We sought to establish an expert consensus regarding the recommendations for VD supplementation in Latin America by means of the Delphi methodology.

RESULTS

The prophylactic dosage of VD in the general population should be individualized according to age, race, body weight, sun exposure of an individual, altitude, and dietary and exercise habits, without ruling out existing chronic diseases.

CONCLUSION

The importance of VD has been widely documented and its deficiency is a pandemic. Many individuals have difficulty meeting daily VD requirements through food and the sun. The population of Latin America and the Caribbean has diverse ethnics, cultures, in addition to living in different latitudes and altitudes. Therefore, it is important to make a position on VD supplementation, given the different characteristics, ages and serum levels of 25(OH)D.

Knowledge and Patterns of Dietary Supplement Use among Students Attending King Abdulaziz University in Saudi Arabia: A Cross-Sectional Study

Oral dietary supplements (DSs) include vitamins, minerals, amino acids, energy drinks, and herbal products. The use of DSs is increasing and their manufacturers promote their benefits. Studies have validated some of these benefits, but have also indicated that some DSs can have adverse effects, especially if used without the appropriate supervision. Little information on DS use among Saudis is available. This study assessed the use of dietary supplements among male and female university students with the goal of educating the community about DSs and the dangers associated with their misuse. Online and paper validated questionnaires were administered to King Abdulaziz University (KAU) students between September 2019 and January 2020. The responses were collected and analyzed statistically. Of the 954 KAU students who completed the survey, one-third used DSs (42.9% women vs 25.7% men). Of these, 51.7% believed that DSs are essential for health, 41.7% classified them as both food and drugs, 67.2% were aware that DSs could not replace a healthy diet, and 25.8% were aware of their potentially harmful effects. Multivitamins and minerals were the most used DSs. DS awareness among KAU students is limited. Additional health education is necessary to assist students in their selection of the most suitable DSs.

Vitamin D and cardiovascular health

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

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.

The Benefits of Vitamin D Supplementation for Athletes: Better Performance and Reduced Risk of COVID-19

The COVID-19 pandemic is having major economic and personal consequences for collegiate and professional sports. Sporting events have been canceled or postponed, and even when baseball and basketball seasons resumed in the United States recently, no fans were in attendance. As play resumed, several players developed COVID-19, disrupting some of the schedules. A hypothesis now under scientific consideration is that taking vitamin supplements to raise serum 25-hydroxyvitamin D [25(OH)D] concentrations could quickly reduce the risk and/or severity of COVID-19. Several mechanisms have been identified through which vitamin D could reduce the risks of infection and severity, death, and long-haul effects of COVID-19: (1) inducing production of cathelicidin and defensins to reduce the survival and replication of the SARS-CoV-2 virus; (2) reducing inflammation and the production of proinflammatory cytokines and risk of the "cytokine storm" that damages the epithelial layer of the lungs, heart, vascular system, and other organs; and (3) increasing production of angiotensin-converting enzyme 2, thus limiting the amount of angiotensin II available to the virus to cause damage. Clinical trials have confirmed that vitamin D supplementation reduces risk of acute respiratory tract infections, and approximately 30 observational studies have shown that incidence, severity, and death from COVID-19 are inversely correlated with serum 25(OH)D concentrations. Vitamin D supplementation is already familiar to many athletes and sports teams because it improves athletic performance and increases playing longevity. Thus, athletes should consider vitamin D supplementation to serve as an additional means by which to reduce risk of COVID-19 and its consequences.

A dose-response meta-analysis between serum concentration of 25-hydroxy vitamin D and risk of type 1 diabetes mellitus

It remains debatable whether vitamin D plays any role as a risk factor for type 1 diabetes mellitus (T1DM). We have summarized the effect of circulating 25-hydroxy vitamin D [25(OH)D] concentration on the risk of developing T1DM via a dose-response meta-analysis. We undertook a database search on PubMed, Embase, and Cochrane Library from inception to January 2020. A meta-analysis based on random-effects model was applied. Subgroup analysis and meta-regression were performed to inspect the source of heterogeneity. Dose-response data were examined using the generalized least squares trend estimation method. This study was registered with the PROSPERO (ID: CRD42020166174). In total, 16 studies including 10,605 participants (3913 case patients) were included. The pooled odds ratios (OR) and 95% confidence intervals (95% CI) for the highest versus the lowest 25(OH)D concentration was 0.39 (0.27, 0.57), with a high heterogeneity (I² = 76.7%, P < 0.001). Meta-regression analysis identified latitude (P = 0.02), adjustment for gender (P = 0.001), and 25(OH)D stratification (P < 0.001) as sources of heterogeneity. Furthermore, the nonlinear dose-response analysis determined the OR (95% CI) of T1DM to be 0.91 (0.90, 0.93) per 10 nmol/L increase in the 25(OH)D concentration. A 'U'-shaped association was found between serum 25(OH)D concentration and risk of T1DM. The present study highlights the significant inverse association between the circulating 25(OH)D concentration and the risk of T1DM.

Vitamin D Binding Protein (VDBP) and Its Gene Polymorphisms-The Risk of Malignant Tumors and Other Diseases

Vitamin D is an important component of the endocrine system that controls calcium homeostasis and bone mineralization. Because of the very short half-life of free serum vitamin D it is stabilized and transported to target tissues by being bound to the vitamin D binding protein (VDBP). The most common polymorphisms: rs4588 and rs7041 in the vitamin D binding protein gene may correlate with differences in vitamin D status in the serum. This review presents data that relate to the presence of genetic variants in the VDBP gene in correlation with certain diseases, mostly concerning cancers (breast, prostate, pancreatic, lung, colorectal, basal cell carcinoma cancer and cutaneous melanoma) or other related diseases (thyroid autoimmunity disorders, obesity, diabetes mellitus, bone metabolism, rheumatoid arthritis, ankylosing spondylitis, asthma, chronic obstructive pulmonary disease, tuberculosis and coronary artery diseases).

Vitamin D Deficiency Induces Elevated Oxidative and Biomechanical Damage in Coronary Arterioles in Male Rats

Background: Several reports prove interconnection between vitamin D (VD) deficiency and increased cardiovascular risk. Our aim was to investigate the effects of VD status on biomechanical and oxidative–nitrative (O–N) stress parameters of coronary arterioles in rats. Methods: 4-week-old male Wistar rats were divided into a control group (11 animals) with optimal VD supply (300 IU/kgbw/day) and a VD-deficient group (11 animals, <5 IU/kg/day). After 8 weeks, coronary arteriole segments were prepared. Geometrical, elastic, and biomechanical characteristics were measured by in vitro arteriography. O–N stress markers were investigated by immunohistochemistry. Results: Inner radius decreased; wall thickness and wall-thickness/lumen diameter ratio increased; tangential wall stress and elastic modulus were reduced in VD-deficient group. No difference could be found in wall-cross-sectional area, intima-media area %. While the elastic elements of the vessel wall decreased, the α-smooth muscle actin (α-SMA) immunostaining intensity showed no changes. Significant elevation was found in the lipid peroxidation marker of 4-hidroxy-2-nonenal (HNE), while other O–N stress markers staining intensity (poly(ADP)ribose, 3-nitrotyrosine) did not change. Conclusions: Inward eutrophic remodeling has developed. The potential background of these impairments may involve the initial change in oxidative damage markers (HNE). These mechanisms can contribute to the increased incidence of the cardiovascular diseases in VD deficiency.

Genomics in Personalized Nutrition: Can You "Eat for Your Genes"?

Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations based on an individual's genetic variability at multiple SNPs. However, relatively little is known about most specific gene-diet interactions, and many molecular and clinical phenotypes of interest (e.g., body mass index [BMI]) involve multiple genes. In this review, we discuss direct to consumer genetic testing (DTC-GT) and the current potential for precision nutrition based on an individual's genetic data. We review important issues such as dietary exposure and genetic architecture addressing the concepts of penetrance, pleiotropy, epistasis, polygenicity, and epigenetics. More specifically, we discuss how they complicate using genotypic data to predict phenotypes as well as response to dietary interventions. Then, several examples (including caffeine sensitivity, alcohol dependence, non-alcoholic fatty liver disease, obesity/appetite, cardiovascular, Alzheimer's disease, folate metabolism, long-chain fatty acid biosynthesis, and vitamin D metabolism) are provided illustrating how genotypic information could be used to inform nutritional recommendations. We conclude by examining ethical considerations and practical applications for using genetic information to inform dietary choices and the future role genetics may play in adopting changes beyond population-wide healthy eating guidelines.

Understanding the Biological Activities of Vitamin D in Type 1 Neurofibromatosis: New Insights into Disease Pathogenesis and Therapeutic Design

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Vitamin D levels are not exclusively dependent on food intake. Indeed, the endogenous production-occurring in the skin and dependent on sun exposure-contributes to the majority amount of vitamin D present in the body. Since vitamin D receptors (VDRs) are ubiquitous and drive the expression of hundreds of genes, the interest in vitamin D has tremendously grown and its role in different diseases has been extensively studied. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available. In this context, vitamin D or its analogues have been used to treat both skin and bone lesions in NF1 patients, alone or combined with other therapeutic agents. Here we provide an overview of vitamin D, its characteristic nutritional properties relevant for health benefits and its role in NF1 disorder. We focus on preclinical and clinical studies that demonstrated the clinical correlation between vitamin D status and NF1 disease, thus providing important insights into disease pathogenesis and new opportunities for targeted therapy.

Pleiotropic actions of Vitamin D in composite musculoskeletal trauma

Composite tissue injuries are the result of high energy impacts caused by motor vehicle accidents, gunshot wounds or blasts. These are highly traumatic injuries characterized by wide-spread, penetrating wounds affecting the entire musculoskeletal system, and are generally defined by frank volumetric muscle loss with concomitant segmental bone defects. At the tissue level, the breadth of damage to multiple tissue systems, and potential for infection from penetration, have been shown to lead to an exaggerated, often chronic inflammatory response with subsequent dysregulation of normal musculoskeletal healing mechanisms. Aside from the direct effects of inflammation on myogenesis and osteogenesis, frank muscle loss has been shown to directly impair fracture union and ultimately contribute to failed wound regeneration. Care for these injuries requires extensive surgical intervention and acute care strategies. However, often these interventions do not adequately mitigate inflammation or promote proper musculoskeletal injury repair and force amputation of the limb. Therefore, identification of factors that can promote tissue regeneration and mitigate inflammation could be key to restoring wound healing after composite tissue injury. One such factor that may directly affect both inflammation and tissue regeneration in response to these multi-tissue injuries may be Vitamin D. Beyond traditional roles, the pleiotropic and localized actions of Vitamin D are increasingly being recognized in most aspects of wound healing in complex tissue injuries - e.g., regulation of inflammation, myogenesis, fracture callus mineralization and remodeling. Conversely, pre-existing Vitamin D deficiency leads to musculoskeletal dysfunction, increased fracture risk or fracture non-unions, decreased strength/function and reduced capacity to heal wounds through increased inflammation. This Vitamin D deficient state requires acute supplementation in order to quickly restore circulating levels to an optimal level, thereby facilitating a robust wound healing response. Herein, the purpose of this review is to address the roles and critical functions of Vitamin D throughout the wound healing process. Findings from this review suggest that careful monitoring and/or supplementation of Vitamin D may be critical for wound regeneration in composite tissue injuries.

Impact of Vitamin D Deficiency on COVID-19-A Prospective Analysis from the CovILD Registry

The novel Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a global health concern. Vitamin D (VITD) deficiency has been suggested to alter SARS-CoV-2 susceptibility and the course of disease. Thus, we aimed to investigate associations of VITD status to disease presentation within the CovILD registry. This prospective, multicenter, observational study on long-term sequelae includes patients with COVID-19 after hospitalization or outpatients with persistent symptoms. Eight weeks after PCR confirmed diagnosis, a detailed questionnaire, a clinical examination, and laboratory testing, including VITD status, were evaluated. Furthermore, available laboratory specimens close to hospital admission were used to retrospectively analyze 25-hydroxyvitamin D levels at disease onset. A total of 109 patients were included in the analysis (60% males, 40% females), aged 58 ± 14 years. Eight weeks after the onset of COVID-19, a high proportion of patients presented with impaired VITD metabolism and elevated parathyroid hormone (PTH) levels. PTH concentrations were increased in patients who needed intensive care unit (ICU) treatment, while VITD levels were not significantly different between disease severity groups. Low VITD levels at disease onset or at eight-week follow-up were not related to persistent symptom burden, lung function impairment, ongoing inflammation, or more severe CT abnormalities. VITD deficiency is frequent among COVID-19 patients but not associated with disease outcomes. However, individuals with severe disease display a disturbed parathyroid-vitamin-D axis within their recovery phase. The proposed significance of VITD supplementation in the clinical management of COVID-19 remains elusive.

Effects of vitamin D on mood and sleep in the healthy population: Interpretations from the serotonergic pathway

Vitamin D insufficiency is common in the healthy population. Recent insights addressed the role of vitamin D in serotonin and melatonin regulation, suggesting that increasing vitamin D status may be helpful for improving mood and sleep. This literature review covers the current state of evidence regarding potential effects of vitamin D on mood and sleep indicators in healthy people. In total, 11 observational studies were found for sleep, and 54 studies on mood (including ten RCTs). These studies revealed mixed results for both sleep and mood. The findings were interpreted based on the previously proposed serotonergic pathway of vitamin D. Implications and challenges for future research regarding the timing of blood sampling, timing and dosage of supplement intake and investigating the response dynamics are discussed.

Vitamin D can be effective on the prevention of COVID-19 complications: A narrative review on molecular aspects

The widespread COVID-19 pandemic has been, currently, converted to a catastrophic human health challenge. Vitamin D (VD) and its metabolites have been used as a palliative treatment for chronic inflammatory and infectious diseases from ancient times. In the current study, some molecular aspects of the potential effects of VD against COVID-19 side-effects have been discussed. An arguable role in autophagy or apoptosis control has been suggested for VD through calcium signaling at the mitochondrial and ER levels. 1,25(OH)2D3 is also an immunomodulator that affects the development of B-cells, T-cells, and NK cells in both innate and acquired immunity. The production of some anti-microbial molecules such as defensins and cathelicidins is also stimulated by VD. The overexpression of glutathione, glutathione peroxidase, and superoxide dismutase, and down-regulation of NADPH oxidase are induced by VD to reduce the oxidative stress. Moreover, the multi-organ failure due to a cytokine storm induced by SARS-CoV2 in COVID-19 may be prevented by the immunomodulatory effects of VD. It can also downregulate the renin-angiotensin system which has a protective role against cardiovascular complications induced by COVID-19. Given the many experimental and molecular evidences due to the potential protective effects of VD on the prevention of the COVID-19-induced morbidities, a VD supplementation is suggested to prevent the lethal side-effects of the infection. It is particularly recommended in VD-deficient patients or those at greater risk of serious or critical effects of COVID-19, including the elderly, and patients with pre-existing chronic diseases, especially those in nursing homes, care facilities, and hospitals.

Ionizing Radiation as a Source of Oxidative Stress-The Protective Role of Melatonin and Vitamin D

Ionizing radiation (IR) has found widespread application in modern medicine, including medical imaging and radiotherapy. As a result, both patients and healthcare professionals are exposed to various IR doses. To minimize the negative side effects of radiation associated with oxidative imbalance, antioxidant therapy has been considered. In this review, studies on the effects of melatonin and vitamin D on radiation-induced oxidative stress are discussed. According to the research data, both substances meet the conditions for use as agents that protect humans against IR-induced tissue damage. Numerous studies have confirmed that melatonin, a hydro- and lipophilic hormone with strong antioxidant properties, can potentially be used as a radioprotectant in humans. Less is known about the radioprotective effects of vitamin D, but the results to date have been promising. Deficiencies in melatonin and vitamin D are common in modern societies and may contribute to the severity of adverse side effects of medical IR exposure. Hence, supporting supplementation with both substances seems to be of first importance. Interestingly, both melatonin and vitamin D have been found to selectively radiosensitise cancer cells, which makes them promising adjuvants in radiotherapy. More research is needed in this area, especially in humans.

Bone health in childhood cancer: review of the literature and recommendations for the management of bone health in childhood cancer survivors

In the past decades, new cancer treatment approaches for children and adolescents have led to a decrease in recurrence rates and an increase in long-term survival. Recent studies have focused on the evaluation of the late effects on bone of pediatric cancer-related treatments, such as chemotherapy, radiation and surgery. Treatment of childhood cancer can impair the attainment of peak bone mass, predisposing to premature onset of low bone mineral density, or causing other bone side-effects, such as bone quality impairment or avascular necrosis of bone. Lower bone mineral density and microarchitectural deterioration can persist during adulthood, thereby increasing fracture risk. Overall, long-term follow-up of childhood cancer survivors is essential to define specific groups at higher risk of long-term bone complications, identify unrecognized long-term adverse effects, and improve patient care. Children and adolescents with a cancer history should be carefully monitored, and patients should be informed of possible late complications of their previous medical treatment. The International Osteoporosis Foundation convened a working group to review the bone complications of pediatric cancer survivors, outlining recommendations for the management of bone health, in order to prevent and treat these complications.

Vitamin D receptor(s): In the nucleus but also at membranes?

The genomic actions of the vitamin D are mediated via its biologically most potent metabolite 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂ D₃ ) and the transcription factor vitamin D receptor (VDR). Activation of VDR by 1,25(OH)₂ D₃ leads to change in the expression of more 1000 genes in various human tissues. Based on (epi)genome, transcriptome and crystal structure data the molecular details of this nuclear vitamin D signalling pathway are well understood. Vitamin D is known for its role on calcium homeostasis and bone formation, but it also modulates energy metabolism, innate and adaptive immunity as well as cellular growth, differentiation and apoptosis. The observation of rapid, non-genomic effects of 1,25(OH)₂ D₃ at cellular membranes and in the cytosol initiated the question, whether there are alternative vitamin D-binding proteins in these cellular compartments. So far, the best candidate is the enzyme PDIA3 (protein disulphide isomerase family A member 3), which is found at various subcellular locations. Furthermore, also VDR seems to play a role in membrane-based responses to vitamin D. In this viewpoint, we will dispute whether these rapid, non-genomic pathways are a meaningful addition to the genome-wide effects of vitamin D.

What factors modify the effect of monthly bolus dose vitamin D supplementation on 25-hydroxyvitamin D concentrations?

The increasing use of vitamin D supplements has stimulated interest in identifying factors that may modify the effect of supplementation on circulating 25-hydroxyvitamin D (25(OH)D) concentrations. Such information is of potential interest to researchers, clinicians and patients when deciding on bolus dose of vitamin D supplementation. We carried out a large randomized controlled trial of 5110 adults aged 50-84 years, of European/Other (84%), Polynesian (11%) and Asian (5%) ethnicity, to whom we gave a standard dose of vitamin D₃ supplements (200,000 IU initially, then 100,000 IU monthly) which was taken with high adherence. All participants provided a baseline blood sample, and follow-up blood samples were collected at 6 months and annually for 3 years in a random sample of 441 participants, and also at 2 years in 413 participants enrolled in a bone density sub-study. Serum 25(OH)D was measured by LC/MSMS. Mixed model analyses were carried out on all 854 participants providing follow-up blood samples in multivariable models that included age, sex, ethnicity, body mass index (kg/m²), tobacco smoking, alcohol intake, physical activity, sun exposure, season, medical prescription of high-dose vitamin D₃ (Cal.D.Forte tablets), asthma/COPD and the study treatment (vitamin D or placebo). The adjusted mean difference in 25(OH)D in the follow-up points between vitamin D supplementation and placebo groups was inversely related (all p for interaction <0.05) to baseline 25(OH)D, BMI, and hours of sun exposure, and higher in females, elders, and those with high frequency of alcohol, medical prescription of vitamin D, and asthma/COPD. The mean difference was not significantly related to ethnicity (p = 0.12), tobacco (p = 0.34), and vigorous activity (p = 0.33). In summary, these data show that vitamin D status, BMI, sun exposure hours, sex and asthma/COPD modify the 25(OH)D response to vitamin D supplementation. By contrast, ethnicity, tobacco smoking, and vigorous activity do not.

The Effect of Vitamin D3 Supplementation on Physical Capacity among Active College-Aged Males

Vitamin D₃ supplementation can affect strength and power; however, the effect on both aerobic and anaerobic performance remains unclear. Here, we investigate the effects of eight weeks of a high dose of vitamin D₃ supplementation and its impact on circulating 25-hydroxyvitamin D (25-OH-D₃) concentrations and selected indicators of physical capacity. Subjects (n = 28, age 21.1 ± 1.6) were divided into two groups: supplemented (SUP), which was given 6000 IU of vitamin D₃ daily for eight weeks; and placebo group (PLA). Serum 25-OH-D₃ concentrations were determined in pre- and post-intervention. Aerobic (V.O_2max test) and anaerobic (Wingate Anaerobic Test) capacity were determined before and after the supplementation. The mean baseline concentration of 25-OH-D₃ was recognized as deficient (20 ng/mL) and significantly increased over time in the supplemented group (p < 0.01, η² = 0.86), whilst it remained unchanged in the placebo group. Moreover, the supplementation caused a significant improvement in maximal aerobic (p < 0.05, η² = 0.27) and anaerobic power (p < 0.01, η² = 0.51) whereas no changes were observed in PLA group. The V.O_2max differences were also significant in the supplemented group (p < 0.05). In summary, the changes in aerobic and anaerobic capacity observed in this study were associated with a serum concentration of 25-OH-D₃. Our data imply that vitamin D₃ supplementation with a dose of 6000 IU daily for eight weeks is sufficient to improve physical capacity and vitamin D₃ status.

Vitamin D3 and Dental Mesenchymal Stromal Cells

Vitamin D3 is a hormone involved in the regulation of bone metabolism, mineral homeostasis, and immune response. Almost all dental tissues contain resident mesenchymal stromal cells (MSCs), which are largely similar to bone marrow-derived MSCs. In this narrative review, we summarized the current findings concerning the physiological effects of vitamin D3 on dental MSCs. The existing literature suggests that dental MSCs possess the ability to convert vitamin D3 into 25(OH)D3 and subsequently to the biologically active 1,25(OH)2D3. The vitamin D3 metabolites 25(OH)D3 and 1,25(OH)2D3 stimulate osteogenic differentiation and diminish the inflammatory response of dental MSCs. In addition, 1,25(OH)2D3 influences the immunomodulatory properties of MSCs in different dental tissues. Thus, dental MSCs are both producers and targets of 1,25(OH)2D3 and might regulate the local vitamin D3-dependent processes in an autocrine/paracrine manner. The local vitamin D3 metabolism is assumed to play an essential role in the local physiological processes, but the mechanisms of its regulation in dental MSCs are mostly unknown. The alteration of the local vitamin D3 metabolism may unravel novel therapeutic modalities for the treatment of periodontitis as well as new strategies for dental tissue regeneration.

Association between serum vitamin D and depressive symptoms in apparently healthy male adults undergoing routine health check-ups at a single centre

OBJECTIVE

To determine the level of vitamin D and to identify the association between vitamin D and depressive symptoms in apparently healthy Korean male adults.

DESIGN

A retrospective study design. Among 43 513 participants between 1 March and 30 November 2018, after eliminating participants with a history of depression or vitamin D deficiency, 9058 were included. To determine the level of vitamin D, serum 25-hydroxyvitamin D [25(OH)D] was measured. To assess the level of depression, the Korean version of the Center for Epidemiologic Studies Depression Scale (CES-D) was used.

SETTING

South Korea.

PARTICIPANTS

Male adults who underwent routine health check-ups.

RESULTS

The average vitamin D level was 22·31 ± 7·09 ng/ml as 25(OH)D, while the number of subjects in the vitamin D insufficiency group with a finding of <20 ng/ml was 3783 (41·8 %). The mean CES-D score in all subjects was 8·31 ± 5·97 points, and the proportion of the depressive symptoms group with a score of ≥16 was 8·71 %. The OR of patients in the depressive symptoms group also being in the insufficiency group was found to be 1·49 (95 % CI 1·12, 2·00).

CONCLUSIONS

A total of 41·8 % of apparently healthy male adults had vitamin D levels <20 ng/ml. We identified an association between vitamin D insufficiency and depressive symptoms in apparently healthy Korean male adults.

Ocular and Systemic Effects of Antioxidative Supplement Use in Young and Healthy Adults: Real-World Cross-Sectional Data

Randomized controlled studies have shown that antioxidative supplements are effective in suppressing the progression of age-related macular degeneration and visual display terminal syndrome. However, effects of their general use in the real-world and by young and healthy individuals have not been well documented. We analyzed 27 participants who were under 35 years of age and had no diagnosed diseases. Mean functional visual acuity (FVA) score and visual maintenance ratio, which represent quick recognition of a target, both measured using FVA system, were better (both p < 0.01) in subjects who had had regular antioxidative supplement intake for more than 2 months (11 participants) compared with those who had not. Systemic data, i.e., total cholesterol, hemoglobin A1c (HbA1c), and high-sensitivity C-reactive protein (hs-CRP) levels, which correspond to chronic low-grade inflammation, were lower (all p < 0.05) in the former. Overall, hs-CRP levels had a correlation with total cholesterol (p < 0.05) and a trend of correlation with HbA1c (p = 0.054) levels. Thus, current real-world data showed that young, healthy participants who had a regular intake of antioxidative supplements had better visual acuity and systemic levels of metabolic and low-grade inflammation markers. This study will help promote future research into the effects of general antioxidative supplement use.

Adherence to Vitamin D Intake Guidelines in the United States

BACKGROUND

The American Academy of Pediatrics (AAP) revised its infant vitamin D intake guidelines in 2008. We aimed to examine previously unexplored trends in meeting vitamin D intake guidelines among US infants since 2009 and whether there were differences across demographic subgroups.

METHODS

We analyzed dietary recall data for infants 0 to 11 months in the 2009-2016 NHANES. We estimated the percentage meeting 2008 AAP vitamin D guidelines, defined as consuming ≥1 L of infant formula and/or receiving a vitamin D supplement of ≥400 IU. We used Poisson regressions to assess trends over time and differences across demographic subgroups.

RESULTS

Overall, 27.1% (95% confidence interval [CI]: 24.3%-29.8%) of US infants in 2009-2016 met vitamin D intake guidelines, with nonbreastfeeding infants (31.1% [95% CI: 27.6%-34.5%]) more likely to meet guidelines than breastfeeding infants (20.5% [95% CI: 15.4%-25.5%]; P < .01). From 2009-2010 to 2015-2016, overall and for both breastfeeding and nonbreastfeeding infants, there were no significant changes over time in the percentage of infants who met the guidelines (P > .05). Among breastfeeding infants, those with a family income ≥400% of the federal poverty level, with a college graduate head of household, and with private insurance were more likely to meet guidelines.

CONCLUSIONS

Among US infants, we observed no increase in meeting AAP vitamin D intake guidelines since 2009. Less than 40% of infants met guidelines in nearly all demographic subgroups. These findings suggest renewed consideration of how to best meet vitamin D intake guidelines.

Calcium, vitamin D, vitamin K2, and magnesium supplementation and skeletal health

Supplementation with calcium (Ca) and/or vitamin D (vitD) is key to the management of osteoporosis. Other supplements like vitamin K2 (VitK2) and magnesium (Mg) could contribute to the maintenance of skeletal health. This narrative review summarizes the most recent data on Ca, vitD, vitK2 and Mg supplementation and age-related bone and muscle loss. Ca supplementation alone is not recommended for fracture prevention in the general postmenopausal population. Patients at risk of fracture with insufficient dietary intake and absorption could benefit from calcium supplementation, but it needs to be customized, taking into account possible side-effects and degree of adherence. VitD supplementation is essential in patients at risk of fracture and/or vitD deficiency. VitK2 and Mg both appear to be involved in bone metabolism. Data suggest that VitK2 supplementation might improve bone quality and reduce fracture risk in osteoporotic patients, potentially enhancing the efficacy of Ca ± vitD. Mg deficiency could negatively influence bone and muscle health. However, data regarding the efficacy of vitK2 and Mg supplementation on bone are inconclusive.

Pharmacokinetics of Oral Cholecalciferol in Healthy Subjects with Vitamin D Deficiency: A Randomized Open-Label Study

BACKGROUND

the aim of this study was to investigate the pharmacokinetic (PK) and safety profile of high-dose vitamin D supplementation, comparing different schedules (daily, weekly, or bi-weekly) in an otherwise healthy vitamin D-deficient population. Methods: single-center, open-label study on healthy subjects deficient in vitamin D (25 (OH)D < 20 ng/mL), randomized to receive cholecalciferol (DIBASE^®, Abiogen Pharma, Italy) using three different schedules: Group A: 10,000 IU/day for eight weeks followed by 1000 IU/day for four weeks; Group B: 50,000 IU/week for 12 weeks, Group C: 100,000 IU/every other week for 12 weeks. Total cumulative doses were: 588,000 IU, 600,000 IU, 600,000 IU. The treatment regimens corresponded to the highest doses allowed for cholecalciferol for the correction of vitamin D deficiency in adults in Italy.

RESULTS

mean 25 (OH)D plasma levels significantly increased from baseline 13.5 ± 3.7 ng/mL to peak values of 81.0 ± 15.0 ng/mL in Group A, 63.6 ± 7.9 ng/mL in Group B and 59.4 ± 12 ng/mL in Group C. On day 28, all subjects showed 25 (OH)D levels ≥ 20 ng/mL and 93.1% had 25 (OH)D levels ≥ 30 ng/mL. On day 56 and 84, all subjects had 25 (OH)D levels ≥ 30 ng/mL. No serious adverse events occurred during the study.

CONCLUSIONS

normalization of 25 (OH)D serum levels was quickly attained with all the studied regimens. A more refracted schedule provided a higher systemic 25 (OH)D exposure.