An evaluation of the relative contributions of exposure to sunlight and of diet to the circulating concentrations of 25-hydroxyvitamin D in an elderly nursing home population in Boston

Comparative Study of Healthy Older and Younger Adults Shows They Have the Same Skin Concentration of Vitamin D3 Precursor, 7-Dehydrocholesterol, and Similar Response to UVR

Vitamin D3 synthesis in human skin is initiated by solar ultraviolet radiation (UVR) exposure of precursor 7-dehydrocholesterol (7DHC), but influence of age on the early stage of vitamin D3 metabolism is uncertain. We performed a prospective standardised study in healthy ambulant adults aged ≥65 and ≤40 years examining (1) if baseline skin 7DHC concentration differs between younger and older adults and (2) the impact of older age on serum vitamin D3 response to solar simulated UVR. Eleven younger (18-40 years) and 10 older (65-89 years) adults, phototype I-III, received low-dose UVR (95% UVA, 5% UVB, 1.3 SED) to ~35% of the body surface area. Biopsies were taken for 7DHC assay from unexposed skin, skin immediately and 24 h post-UVR, and blood sampled at baseline, 24 h and 7 d post-UVR for vitamin D3 assay. Samples were analysed by HPLC-MS/MS. Baseline skin 7DHC (mean ± SD) was 0.22 ± 0.07 and 0.25 ± 0.08 µg/mg in younger versus older adults (no significant difference). Baseline serum vitamin D3 concentration was 1.5 ± 1.5 and 1.5 ± 1.7 nmol/L in younger versus older adults, respectively, and showed a significant increase in both groups post-UVR (no significant differences between age groups). Thus, skin 7DHC concentration was not a limiting factor for vitamin D3 production in older relative to younger adults. This information assists public health guidance on sun exposure/vitamin D nutrition, with particular relevance to the growing populations of healthy ambulant adults ≥65 years.

Circulating retinol and 25(OH)D contents and their association with symptoms in children with chronic tic disorders

The present study measured serum levels of vitamin A (VA) and vitamin D (VD) in children with chronic tic disorders (CTD) and investigated their potential association with CTD and comorbidity of attention deficit hyperactivity disorder (ADHD) and the association of their co-insufficiencies or deficiencies with CTD symptoms. A total of 176 children (131 boys and 45 girls, median age of 9 years) with CTD were recruited as the CTD group. During the same period, 154 healthy children were selected as the healthy control (HC) cohort. Circulating retinol and 25-hydroxyvitamin D (25[OH]D) levels were measured for all participants using high-performance liquid chromatography (HPLC) and tandem mass spectrometry. The Yale Global Tic Severity Scale (YGTSS) was employed for the assessment of tic status and CTD impairment. The Swanson, Nolan, and Pelham Rating Scale (SNAP-IV) and the Children's Yale-Brown Obsessive-Compulsive Scale (CY-BOCS) were used to evaluate comorbidity symptoms. CTD pediatric participants exhibited markedly diminished circulating retinol and 25(OH)D levels compared to HCs. Moreover, VA and VD deficiencies and their co-insufficiencies/deficiencies were more prevalent in CTD participants than HCs. Circulating 25(OH)D levels were inversely proportional to the YGTSS motor tic scores. YGTSS scores in CTD children with only VA or VD insufficiency or deficiency or with VA and VD co-insufficiency/deficiency did not differ from those in CTD children with normal VA and VD. CTD children with comorbid ADHD displayed reduced circulating retinol and 25(OH)D concentrations and elevated prevalence of VD deficiency compared to CTD participants without comorbid ADHD. Lower serum retinol content was intricately linked to the presence of elevated CTD and comorbid ADHD. VA and VD deficiencies and their co-insufficiencies/deficiencies were markedly enhanced in CTD pediatric participants compared to HCs. Lower VA concentration was linked to the presence of enhanced CTD and comorbid ADHD. Therefore, children with CTD, especially with comorbid ADHD, may be at a higher risk of VA or VD deficiency, which may prompt the clinicians to consider whether blood tests for VA and VD in CTD children would be helpful for clinical care.

Osteoporosis and dermatoporosis: a review on the role of vitamin D

Osteoporosis (OP) and Dermatoporosis (DP) are expressions of the aging process at the skin and bone levels, respectively. Both conditions are associated with increased morbidity for elderly people, and this requires necessary interventions. They share many common risk factors; among these, vitamin D (VD) deficiency appears to have a role. VD is involved in either disease with many mechanisms, among which immunomodulation. VD deficiency has been linked to OP because it inhibits the body's capacity to absorb calcium and maintain optimal bone health. Available evidence suggests that proper vitaminosis D also appears to be vital in preventing skin age-related issues. DP is often seen in elderly individuals, particularly those with long-term sun exposure and a history of chronic sun damage. VD deficiency can be linked to DP, since its involvement in collagen production, epidermal barrier function, inflammation regulation, wound healing, and sun protection. Aim of this review is to summarize the most updated existing evidence on the role of VD in the development of fragility syndromes such as DP and OP and the possible benefits of VD supplementation as a simple and harmful weapon against aging.

Cross-Sectional Study of Serum Vitamin B12 and Vitamin D3 Levels Amongst Corporate Employees

Background In today's busy world, health is often neglected especially among full-time workers. Consequently, lifestyle disorders such as vitamin deficiencies are increasing, perhaps because of inadequate nutrition and lack of sunlight due to long hours working indoors. These deficiencies can lead to various short-term and long-term complications. Objective To estimate serum levels of vitamin B12 and vitamin D3 among vegetarian employees. Methods and materials A questionnaire about dietary and exercise habits was administered to participants who fulfilled the inclusion criteria and provided informed written consent. Participants also were asked about drug and supplement intake, history of smoking and alcohol, specific symptoms of vitamin B12 and D3 deficiency, and sociodemographic status. Blood samples were collected to estimate serum B12 and D3 levels. Results The results indicated that 14.00% of participants were vitamin B12 deficient and 82.00% were D3 deficient. Differences by gender were not statistically significant; vitamin B12 deficiency was identified in 10.00% of women and 14.44% of men, and vitamin D3 deficiency occurred in 100.00% of the women and 80.00% of men. Among 71 participants aged 35-45 years, 15.49% and 91.55% were deficient in B12 and D3, respectively; among 25 participants aged 46-55, 12.00% and 64.00% were deficient in B12 and D3, respectively; among four participants older than 55, no vitamin B12 deficiency was observed, but 25.00% were deficient in vitamin D3 (p=0.00002). Nearly all (96.15%) participants who reported never exercising were found to be vitamin D3 deficient, compared to 77.02% of those who exercised (OR=0.13, p=0.043). No significant association was found between alcohol consumption and vitamin B12 (p=1) or D3 (p=0.713) deficiency. Conclusions The results revealed a prevalence of both vitamin B12 and D3 deficiencies among corporate employees who identified as vegetarians. Increased awareness, dietary modifications, conscious physical activity, and most importantly, attention to one's health may help improve vitamin sufficiency. Women over age 45 should pay particular attention due to their increased risk of vitamin D3 deficiency. Further research is needed to assess nutrition profiles among other populations to better understand vitamin deficiencies and design adequate preventive measures.

Differential effects of vitamin D on upper and lower body fat-free mass: potential mechanisms

Vitamin D insufficiency is a global health concern and low vitamin D status is regularly associated with reduced muscle mass and sarcopenia in observational research. Recent research using Mendelian randomization (MR) has highlighted the potentially causal positive effect of serum vitamin D (25(OH)D) on total, trunk and upper body appendicular fat-free mass (FFM). However, no such effect was found in lower body FFM, a result that mirrors the outcomes of some vitamin D intervention studies. Here we review the current literature on vitamin D, muscle mass and strength and discuss some potential mechanisms for the differing effects of vitamin D on upper and lower body FFM. In particular, differences in distribution of the vitamin D receptor as well as androgen receptors, in the upper and lower body musculature, will be discussed.

Serum 25-hydroxyvitamin D and cancer-related fatigue: associations and effects on depression, anxiety, functional capacity and health-related quality of Life in breast cancer survivors during adjuvant endocrine therapy

Background

The adjuvant treatment with Aromatase Inhibitor (AI) is considered standard of care for postmenopausal breast cancer (BC) women with hormone receptor-positive (HR +), however, it often causes adverse effects such as cancer-related fatigue (CRF). The high prevalence of vitamin D deficiency in postmenopausal women who start adjuvant AI supports the hypothesis that hypovitaminosis D would be one of the biological explanations for toxicity of AI. This study aimed to identify the relationship between 25-hydroxyvitamin D [25(OH)D] and CRF, and to analyze their associations and effects on depression, anxiety, functional disability, muscle/joint aches and HRQL.

Methods

This prospective study included 89 postmenopausal women diagnosed with HR + early BC in adjuvant endocrine therapy with AI. Anthropometric and body composition assessments were performed, as well as dietary assessments by application of 24-h dietary recall, at three time points, totaling 24 months of follow-up. The women completed the Cervantes Scale (CS), Hospital Anxiety and Depression Scale (HADS) and Health Assessment Questionnaire (HAQ). The CRF was determined from the Functional Assessment of Chronic Illness Therapy-fatigue (FACIT-F). The serum 25(OH)D was determined by electrochemiluminescence, with cut-off point above 75 nmol/L adopted as sufficiency. Generalized Linear Model (GLzM) and Generalized Mixed Model (GMM) analysis were used.

Results

At baseline, 36% (n = 32) of the women presented CRF and 39.3% (n = 35) had 25(OH)D below 75 nmol/L. None of the women reached the Estimated Average Requirements (EAR) of vitamin D. The causality between 25(OH)D and CRF was not significant. Longitudinally, lower levels of 25(OH)D had a negative effect on anxiety (p = 0.020), Menopause and Health (p = 0.033) and Vasomotor scores (p = 0.007). Also, the CRF had a negative effect on anxiety (p = 0.028); depression (p = 0.027); functional disability (p = 0.022); HRQL (p = 0.007); Menopause and Health (p = 0.042), Psychological (p = 0.008) and Couple Relations (p = 0.008) domains; and on Health (p = 0.019) and Aging (p = 0.036) subdomains. Vasomotor subdomain (β = -2.279, p = 0.045) and muscle/joint aches (β = -0.779, p = 0.013) were significant with CRF only at baseline.

Conclusions

This study found negative effect of body adiposity on CRF. Still, the clinical relevance of 25(OH)D and CRF is highlighted, especially that of CRF, considering the consistent impact on several adverse effects reported by BC survivors during adjuvant endocrine therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09962-x.

Vitamin D Related Gene Polymorphisms and Cholesterol Levels in a Mediterranean Population

In addition to its role in bone health, vitamin D (VitD) has been implicated in several pathological conditions. Specifically, VitD deficiency has been linked to an increased risk of dyslipidemia. Atherogenic dyslipidemia is characterized by increased low-density lipoprotein-cholesterol (LDL-C) and decreased high-density lipoprotein-cholesterol (HDL-C). In this study, we examined the association of six single nucleotide polymorphisms (SNPs) in VitD-related genes with VitD and lipid levels, in a cohort of 460 Lebanese participants free from chronic diseases. Our results showed no association of the examined SNPs with VitD concentrations. However, the presence of the minor allele in rs10741657G>A of CYP2R1 was associated with increased levels in LDL-C (β = 4.95, p = 0.04)] and decreased levels in HDL-C (β = −1.76, p = 0.007)]. Interestingly, rs10741657G>A interacted with gender to increase LDL-C levels in females (β = 6.73 and p = 0.03) and decrease HDL-C levels in males HDL-C (β = −1.09, p = 0.009). In conclusion, our results suggest that rs10741657 G>A in CYP2R1 is associated with circulating LDL-C and HDL-C levels in a Lebanese cohort. Although this association was gender-specific, where rs10741657G>A was associated with increased LDL in females and decreased HDL in males, the presence of the minor allele A was associated with increased cardiovascular risk in both genders. These findings need to be validated in a larger population. Further investigations are warranted to elucidate the molecular mechanism of VitD polymorphism and dyslipidemia.

Genetically Determined Serum 25-Hydroxyvitamin D Is Associated with Total, Trunk, and Arm Fat-Free Mass: A Mendelian Randomization Study

PURPOSE

Low serum vitamin D status has been associated with reduced muscle mass in observational studies although the relationship is controversial and a causal association cannot be determined from such observations. Two-sample Mendelian randomization (MR) was applied to assess the association between serum vitamin D (25(OH)D) and total, trunk, arm and leg fat-free mass (FFM).

METHODS

MR was implemented using summary-level data from the largest genome-wide association studies (GWAS) on vitamin D (n=73,699) and total, trunk, arm and leg FFM. Inverse variance weighted method (IVW) was used to estimate the causal estimates. Weighted median (WM)-based method, and MR-Egger, leave-one-out were applied as sensitivity analysis.

RESULTS

Genetically higher serum 25(OH)D levels had a positive effect on total (IVW = Beta: 0.042, p = 0.038), trunk (IVW = Beta: 0.045, p = 0.023) and arm (right arm IVW = Beta: 0.044, p = 0.002; left arm IVW = Beta: 0.05, p = 0.005) FFM. However, the association with leg FFM was not significant (right leg IVW = Beta: 0.03, p = 0.238; left leg IVW = Beta: 0.039, p = 0.100). The likelihood of heterogeneity and pleiotropy was determined to be low (statistically non-significant), and the observed associations were not driven by single SNPs. Furthermore, MR pleiotropy residual sum and outlier test did not highlight any outliers.

CONCLUSIONS

Our results illustrate the potentially causal, positive effect of serum 25(OH)D concentration on total, trunk and upper body appendicular fat-free mass.

Directly measured free and total 25-hydroxyvitamin D levels in relation to metabolic health in multi-ethnic postmenopausal females in Saudi Arabia

BACKGROUND

Measurement of free 25-hydroyvitamin D (25(OH)D) status has been suggested as a more representative marker of vitamin D status than that of total 25(OH)D. Previously, free 25(OH)D could only be calculated indirectly; however, a newly developed direct assay for the measurement of free 25(OH)D is now available. The aim of this study therefore was to investigate directly measured total and free vitamin D levels association with metabolic health in postmenopausal healthy women living in Saudi Arabia.

METHODS

A sample of 302 postmenopausal women aged ≥50 years (n = 302) living in Saudi Arabia were recruited in a cross-sectional study design. Blood samples were collected from subjects for measurement of serum levels of total 25(OH)D, directly measured free 25(OH)D, metabolic bone parameters, lipid profile, and other biochemical tests.

RESULTS

A positive correlation was found between directly measured free and total 25(OH)D (r = 0.64, P< 0.0001). Total but not free 25(OH)D showed significant association with serum intact parathyroid hormone (P = 0.004), whilst free 25(OH)D but not total 25(OH)D showed a significant association with total cholesterol and LDL-C (P = 0.032 and P = 0.045, respectively).

CONCLUSIONS

Free 25(OH)D and total 25(OH)D were found to be consistently correlated but with different associations to metabolic health parameters. Further research is needed to determine which marker of vitamin D status would be the most appropriate in population studies.

Sarcopenia during COVID-19 lockdown restrictions: long-term health effects of short-term muscle loss

The COVID-19 pandemic is an extraordinary global emergency that has led to the implementation of unprecedented measures in order to stem the spread of the infection. Internationally, governments are enforcing measures such as travel bans, quarantine, isolation, and social distancing leading to an extended period of time at home. This has resulted in reductions in physical activity and changes in dietary intakes that have the potential to accelerate sarcopenia, a deterioration of muscle mass and function (more likely in older populations), as well as increases in body fat. These changes in body composition are associated with a number of chronic, lifestyle diseases including cardiovascular disease (CVD), diabetes, osteoporosis, frailty, cognitive decline, and depression. Furthermore, CVD, diabetes, and elevated body fat are associated with greater risk of COVID-19 infection and more severe symptomology, underscoring the importance of avoiding the development of such morbidities. Here we review mechanisms of sarcopenia and their relation to the current data on the effects of COVID-19 confinement on physical activity, dietary habits, sleep, and stress as well as extended bed rest due to COVID-19 hospitalization. The potential of these factors to lead to an increased likelihood of muscle loss and chronic disease will be discussed. By offering a number of home-based strategies including resistance exercise, higher protein intakes and supplementation, we can potentially guide public health authorities to avoid a lifestyle disease and rehabilitation crisis post-COVID-19. Such strategies may also serve as useful preventative measures for reducing the likelihood of sarcopenia in general and in the event of future periods of isolation.

Serum Levels of Vitamin A and Vitamin D and Their Association With Symptoms in Children With Attention Deficit Hyperactivity Disorder

Objective: To measure levels of vitamin A (VA) and vitamin D (VD) and the symptomatic association of their co-deficiencies on attention deficit hyperactivity disorder (ADHD) in Chinese children (6-9 years). Methods: Eighty-two children (69 boys and 13 girls; mean age = 7.1 ± 0.9 years at the time of the diagnosis) with ADHD were recruited as ADHD group. A total of 106 healthy children were recruited as the healthy control (HC) group. Serum levels of retinol and 25-hydroxyvitamin D (25(OH)D) of all children were evaluated using high-performance liquid chromatography (HPLC) and HPLC-tandem mass spectrometry. The Swanson, Nolan, and Pelham IV Rating Scale (SNAP-IV) was employed to assess the clinical symptoms of ADHD. Results: Children suffering from ADHD had significantly reduced serum levels of retinol and 25(OH)D compared with those of HCs, and the prevalence of VA deficiency and VD deficiency were higher in children suffering from ADHD. Serum concentrations of 25(OH)D and retinol were linked closely with the presence or absence of ADHD after adjustment for age, body mass index, season of blood sampling, and sun exposure. Serum concentrations of 25(OH)D and retinol showed a negative correlation with the total scores of SNAP-IV. Children with ADHD as well as VA and VD co-deficiency had increased SNAP-IV total scores and ADHD inattention subscale scores. Conclusion: VA deficiency and VD deficiency in children with ADHD were increased in comparison with that in HCs. VA and VD co-deficiency associated with ADHD symptom severity. Attention should be paid to regular testing of VA levels and VD levels. However, the mechanism of VA and VD in ADHD needs to be further studied. Interventional studies on VA and VD supplementation are recommended to further verify the relationship between VA and VD co-deficiency and ADHD.

The Role of Vitamin D and Omega-3 PUFAs in Islet Transplantation

Recurrence of autoimmunity and allograft rejection represent major challenges that impact the success of islet transplantation. Despite the remarkable improvements achieved in immunosuppression strategies after the publication of the Edmonton protocol, long-term data of intra-hepatic islet transplantation show a gradual decline in beta-cell function. Therefore, there is a growing interest in the investigation of novel, safe and effective anti-inflammatory and immunomodulatory strategies able to promote long-term islet graft survival and notable improvements in clinical outcomes of islet transplant recipients. Vitamin D has been shown to exert anti-inflammatory and immunomodulatory effects. Pre-clinical studies investigating the use of vitamin D and its analogs (alone or in combination with immunosuppressive agents and/or other anti-inflammatory agents, such as omega-3 polyunsaturated fatty acids) showed beneficial results in terms of islet graft survival and prevention of recurrence of autoimmunity/allograft rejection in animal models of syngeneic and allogeneic islet transplantation. Moreover, epidemiologic studies demonstrated that vitamin D deficiency is highly prevalent after solid organ transplantation (e.g., heart, liver or kidney transplantation). However, studies that critically assess the prevalence of vitamin D deficiency among islet transplant recipients have yet to be conducted. In addition, prospective studies aimed to address the safety and efficacy of vitamin D supplementation as an adjuvant immunomodulatory strategy in islet transplant recipients are lacking and are therefore awaited in the future.

Influence of Vitamin D on Islet Autoimmunity and Beta-Cell Function in Type 1 Diabetes

Type 1 diabetes (T1D) is a chronic autoimmune disease leading to immune-mediated destruction of pancreatic beta cells, resulting in the need for insulin therapy. The incidence of T1D is increasing worldwide, thus prompting researchers to investigate novel immunomodulatory strategies to halt autoimmunity and modify disease progression. T1D is considered as a multifactorial disease, in which genetic predisposition and environmental factors interact to promote the triggering of autoimmune responses against beta cells. Over the last decades, it has become clear that vitamin D exerts anti-inflammatory and immunomodulatory effects, apart from its well-established role in the regulation of calcium homeostasis and bone metabolism. Importantly, the global incidence of vitamin D deficiency is also dramatically increasing and epidemiologic evidence suggests an involvement of vitamin D deficiency in T1D pathogenesis. Polymorphisms in genes critical for vitamin D metabolism have also been shown to modulate the risk of T1D. Moreover, several studies have investigated the role of vitamin D (in different doses and formulations) as a potential adjuvant immunomodulatory therapy in patients with new-onset and established T1D. This review aims to present the current knowledge on the immunomodulatory effects of vitamin D and summarize the clinical interventional studies investigating its use for prevention or treatment of T1D.

Clinical improvement following vitamin D3 supplementation in children with chronic tic disorders

PURPOSE

Vitamin D deficiency has been found in children with chronic tic disorders (CTDs). Our previous data showed that serum 25-hydroxyvitamin D [25(OH)D] level in children with CTDs was lower than that of the healthy controls and lower serum 25(OH)D level was associated with increased severity of the tic disorder. Thus, we intend to further verify this phenomenon and examine the effect of vitamin D3 on CTDs.

PATIENTS AND METHODS

In total, 120 children with CTDs and 140 normal controls were enrolled in this study, with 36/120 of those in the CTD group receiving vitamin D3 treatment for 3 months. The Yale Global Tic Severity Scale (YGTSS) and Clinical Global Impression of Severity of Illness (CGI-SI) were, respectively, used to evaluate the tic severity. High-performance liquid chromatography and tandem mass spectrometry were used to measure serum 25(OH)D level.

RESULTS

Those children with CTDs exhibited significantly lower 25(OH)D levels than did healthy controls, and these reduced 25(OH)D levels were linked to increasing severity of tic symptoms. After treatment with supplemental vitamin D3, serum 25(OH)D level and scores of YGTSS total, motor tics, phonic tics, total tic, impairment, and CGI-SI improved significantly in children with CTDs without any adverse reactions.

CONCLUSION

Supplementation vitamin D3, given its low cost and excellent safety, may be an effective means of improving symptoms in certain children with CTDs.

Omega-3 PUFAs and vitamin D co-supplementation as a safe-effective therapeutic approach for core symptoms of autism spectrum disorder: case report and literature review

Introduction: Autism spectrum disorder (ASD) is a group of neurodevelopmental disorders characterized by abnormal development of cognitive, social, and communicative skills. Although ASD aetiology and pathophysiology are still unclear, various nutritional factors have been investigated as potential risk factors for ASD development, including omega-3 polyunsaturated fatty acids (PUFAs) and vitamin D deficiency. In fact, both omega-3 PUFAs and vitamin D are important for brain development and function. Case report: Herein, we report the case of a 23-year-old young adult male with autism who was referred to our Unit due to a 12-month history of cyclic episodes of restlessness, agitation, irritability, oppositional and self-injurious behaviours. Laboratory tests documented a markedly altered omega-6/omega-3 balance, along with a vitamin D deficiency, as assessed by serum levels of 25-hydroxyvitamin D. Omega-3 and vitamin D co-supplementation was therefore started, with remarkable improvements in ASD symptoms throughout a 24-month follow-up period. A brief review of the literature for interventional studies evaluating the efficacy of omega-3 or vitamin D supplementation for the treatment of ASD-related symptoms is also provided. Conclusion: To our knowledge, this is the first case reporting remarkable beneficial effects on ASD symptoms deriving from omega-3 and vitamin D combination therapy. This case report suggests omega-3 and vitamin D co-supplementation as a potential safe-effective therapeutic strategy to treat core symptoms of ASD. However, larger studies are needed to evaluate the real efficacy of such therapeutic approach in a broader sample of ASD patients.

Serum 25-hyroxyvitamin D levels and tic severity in Chinese children with tic disorders

The aim of this study is to evaluate serum 25-hydroxyvitamin D[25(OH)D] levels in children with tic disorders and to explore the relationship between serum 25(OH)D level and tic severity. Children (n = 179, 31 females, 148 males, mean age at diagnosis: 8.0 ± 2.7 years old, age ranged from 3 to 14.5 years old) who were diagnosed with a tic disorder were enrolled as case group, 189 healthy children were recruited as control group. Serum level of 25(OH)D of each child was measured by high performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS). Yale Global Tic Severity Scale (YGTSS) was used to assess tic severity. Mean serum level of 25(OH)D in the case group was significantly lower than that of the control group. The serum 25(OH)D level was significantly associated with tic severity after adjusting for age and body mass index (BMI). This study identified a high prevalence of vitamin D insufficiency or deficiency in children with tic disorders, and there was a negative correlation between the serum 25(OH)D level and tic severity. In the future, large sample size studies are urgently needed to further clarify this correlation.

Cross-Sectional Evaluation of Plasma Vitamin D Levels in a Large Cohort of Italian Patients with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections

BACKGROUND

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS) are immune-mediated diseases characterized by obsessive-compulsive symptoms and/or tics triggered by group A Streptococcus infections. Despite the well-known action of 25-hydroxyvitamin D [25(OH)D] on different conditions driven by systemic inflammation, there are no data about the 25(OH)D status in patients with PANDAS.

AIMS

To evaluate plasma 25(OH)D levels in a large cohort of children and adolescents with PANDAS and comparing the results with healthy controls.

METHODS

We have evaluated plasma 25(OH)D levels in 179 Italian patients with PANDAS (49 females, 130 males, mean age at diagnosis: 101.4 ± 30.1 months) and in an age-, gender-, and body mass index-matched control group of 224 healthy subjects.

RESULTS

Patients with PANDAS have shown more frequently reduced 25(OH)D levels (<30 ng/mL) in comparison with controls (94.6% vs. 82.5%, p = 0.0007). Patients with PANDAS had also lower levels of 25(OH)D than controls (20.4 ± 6.9 ng/mL vs. 24.8 ± 7.3 ng/mL, p < 0.0001). This difference was observed during both winter (13.7 ± 3.25 ng/mL vs. 21.4 ± 5.9 ng/mL, p < 0.0001) and summer (21.8 ± 6.5 ng/mL vs. 32.5 ± 8.7 ng/mL, p < 0.0001). Notably, serum 25(OH)D levels correlated with both number of streptococcal (strep) infections before diagnosis of PANDAS (p < 0.005) and with infection recurrence (p < 0.005).

CONCLUSIONS

PANDAS patients have reduced 25(OH)D levels, which appear related to streptococcal infections and the probability of recurrence. Further long-term studies with higher number of patients are needed to investigate and confirm this relationship.

Vitamin D: not just the bone. Evidence for beneficial pleiotropic extraskeletal effects

Vitamin D is a fat-soluble vitamin and a steroid hormone that plays a central role in maintaining calcium-phosphorus and bone homeostasis in close interaction with parathyroid hormone, acting on its classical target tissues, namely, bone, kidney, intestine, and parathyroid glands. However, vitamin D endocrine system regulates several genes (about 3 % of the human genome) involved in cell differentiation, cell-cycle control, and cell function and exerts noncalcemic/pleiotropic effects on extraskeletal target tissues, such as immune and cardiovascular system, pancreatic endocrine cells, muscle, and adipose tissue. Several studies have demonstrated the role of vitamin D supplementation in the prevention/treatment of various autoimmune diseases and improvement of glucose metabolism, muscle, and adipose tissue function. Hence, this review aims to elucidate the effects of vitamin D on extraskeletal target tissues and to investigate the potential therapeutic benefit of vitamin D supplementation among a broad group of pathological conditions, especially with regard to metabolic and autoimmune diseases. In addition, we focused on the best daily intakes and serum levels of vitamin D required for extraskeletal benefits which, even if still controversial, appear to be higher than those widely accepted for skeletal effects.

Greater Adherence to Cancer Prevention Guidelines Is Associated with Higher Circulating Concentrations of Vitamin D Metabolites in a Cross-Sectional Analysis of Pooled Participants from 2 Chemoprevention Trials

Background: Several lifestyle factors targeted by the American Cancer Society (ACS) Nutrition and Physical Activity Cancer Prevention Guidelines are also associated with circulating concentrations of vitamin D metabolites. This suggests that greater adherence to the ACS guidelines may be related to better vitamin D status.Objective: We examined the relation between adherence to the ACS guidelines and circulating concentrations of 2 vitamin D metabolites, 25-hydroxycholecalciferol [25(OH)D] and 1α,25-dihydroxyvitamin D [1,25(OH)₂D].Methods: We conducted cross-sectional analyses of pooled participants from the Wheat Bran Fiber (n = 503) and Ursodeoxycholic Acid (n = 854) trials. A cumulative adherence score was constructed with the use of baseline data on body size, diet, physical activity, and alcohol consumption. Continuous vitamin D metabolite concentrations and clinically relevant categories were evaluated with the use of multiple linear and logistic regression models, respectively.Results: The most adherent participants were more likely to be older, white, and nonsmokers than were the least adherent. A statistically significant association was observed between guideline adherence and concentrations of circulating 25(OH)D (means ± SEs-high adherence: 32.0 ± 0.8 ng/mL; low adherence: 26.4 ± 0.7 ng/mL; P-trend < 0.001). For 1,25(OH)₂D concentrations, high adherence was again significantly related to greater metabolite concentrations, with mean ± SE concentrations of 36.3 ± 1.3 pg/mL and 31.9 ± 1.0 pg/mL for high- and low-adherers, respectively (P-trend = 0.008). Furthermore, the odds of attaining a sufficient 25(OH)D status were 4.37 times higher for those most adherent than for those least adherent (95% CI: 2.47, 7.71 times).Conclusion: These findings demonstrate that greater adherence to the ACS guidelines is associated with higher circulating concentrations of both of 25(OH)D and 1,25(OH)₂D.

Environmental and genetic determinants of vitamin D status among older adults in London, UK

Despite the high prevalence of vitamin D deficiency among older adults in the UK, studies investigating the determinants of vitamin D status in this group are lacking. We conducted a cross-sectional study in 222 older adults living in sheltered accommodation in London, UK, who were screened for participation in a clinical trial of vitamin D supplementation for the prevention of acute respiratory infection. Details of potential demographic and lifestyle determinants of vitamin D status were collected by questionnaire and blood samples were taken for analysis of serum 25-hydroxyvitamin D (25[OH]D) concentration and DNA extraction. Fifteen single nucleotide polymorphisms (SNP) in 6 genes (DBP, DHCR7, CYP2R1, CYP27B1, CYP24A1, VDR) previously reported to associate with circulating 25(OH)D concentration were typed using Taqman allelic discrimination assays. Linear regression was used to identify environmental and genetic factors independently associated with serum 25(OH)D concentration. Mean serum 25(OH)D concentration was 42.7nmol/L (SD 22.0); 144/222 (64.9%) participants had serum 25(OH)D concentrations <50nmol/L. The following factors were independently associated with lower serum 25(OH)D concentration: non-white ethnicity (-8.6nmol/L, 95% CI -14.9 to -2.3, P=0.008); lack of vitamin D supplement consumption (-17.1nmol/L, 95% CI -23.3 to -10.9, P<0.001) vs. taking a daily supplement; sampling in Q1/January-March (-12.2nmol/L, 95% CI -21.5 to -2.9, P=0.01), and sampling in Q4/October-December (-10.3nmol/L, 95% CI -20.2 to -0.4, P=0.04) vs. sampling in Q3/July-September. None of the 15 SNP investigated independently associated with serum 25(OH)D concentration after correcting for multiple comparisons. In conclusion, vitamin D deficiency was highly prevalent among the older adults in this study; non-White ethnicity, lack of vitamin D supplement consumption and sampling in winter and spring independently associated with lower vitamin D status.

Coronary artery disease and its association with Vitamin D deficiency

Coronary artery disease (CAD) has become the latest scourge of humankind and referred to in this article as CAD, is the end result of the accumulation of atheromatous plaques within the walls of coronary arteries that supply the myocardium, a process also known as atherosclerosis and manifests mostly in the form of chronic stable angina or acute coronary syndrome. Vitamin D has attracted considerable interest recently due to its role in a number of extraskeletal disease processes including multiple sclerosis, malignancies, diabetes mellitus, and CAD. It is also known as sunshine vitamin due to its production in the body following exposure to ultraviolet rays, and it is a unique vitamin as it acts like a hormone with its receptor present in a wide range of tissues including endothelium, which is the important mediator of atherosclerosis and subsequent CAD. A large number of studies conducted in the past have provided the basic scientific framework and this article attempts to explore the role of Vitamin D deficiency in the pathogenesis of CAD and stresses the need for further research to fill up gap in our knowledge.

PTH and Vitamin D

PTH and Vitamin D are two major regulators of mineral metabolism. They play critical roles in the maintenance of calcium and phosphate homeostasis as well as the development and maintenance of bone health. PTH and Vitamin D form a tightly controlled feedback cycle, PTH being a major stimulator of vitamin D synthesis in the kidney while vitamin D exerts negative feedback on PTH secretion. The major function of PTH and major physiologic regulator is circulating ionized calcium. The effects of PTH on gut, kidney, and bone serve to maintain serum calcium within a tight range. PTH has a reciprocal effect on phosphate metabolism. In contrast, vitamin D has a stimulatory effect on both calcium and phosphate homeostasis, playing a key role in providing adequate mineral for normal bone formation. Both hormones act in concert with the more recently discovered FGF23 and klotho, hormones involved predominantly in phosphate metabolism, which also participate in this closely knit feedback circuit. Of great interest are recent studies demonstrating effects of both PTH and vitamin D on the cardiovascular system. Hyperparathyroidism and vitamin D deficiency have been implicated in a variety of cardiovascular disorders including hypertension, atherosclerosis, vascular calcification, and kidney failure. Both hormones have direct effects on the endothelium, heart, and other vascular structures. How these effects of PTH and vitamin D interface with the regulation of bone formation are the subject of intense investigation.

Differences in the prevalence of vitamin D deficiency and hip fractures in nursing home residents and independently living elderly

OBJECTIVE

To compare the prevalence of vitamin D deficiency and fracture history in nursing home residents and community-dwelling elderly subjects and to explore the association of vitamin D levels with various characteristics.

MATERIALS AND METHODS

Sixty-six nursing home residents and 139 community-dwelling elderly subjects participated. Marital status, medical history, medication including vitamin D supplements, smoking, past fractures were assessed. Weight and height were measured and body mass index calculated. Serum 25-hydroxyvitamin D (25-OHD), PTH, Ca, phosphate, creatinine and eGFR were determined.

RESULTS

In the nursing home residents 25-OHD was lower (17.8 nmol/l, [9.4-28.6] vs. 36.7 nmol/l, [26.9-50], p < 0.001), PTH was higher (5.6 pmol/l, [3.9-8.9] vs. 4.7 pmol/l [3.6-5.8], P = 0.003) and 25-OHD deficiency was more prevalent (65.2% [53.7-76.7] vs. 22.3% [15.4-29.2], p < 0.001) as was elevated PTH (23% [12.8-33] vs. 5.8% [2-10], p = 0.001). 25-OHD correlated negatively with PTH (institutionalized r = -0.28, p = 0.025 and community-dwelling r = -0.36, p < 0.001). Hip fractures were reported by 8% of the residents and 2% of the independent elderly. The only predictor for hip fracture was elevated PTH (OR = 7.6 (1.5-36.9), p = 0.013).

CONCLUSION

The prevalence of vitamin D deficiency and secondary hyperparathyroidism was high in the institutionalized subjects. Hip fracture risk was associated with elevated PTH and not directly with vitamin D levels or the residency status.

Low Serum 25-Hydroxyvitamin D Levels Are Associated with Dry Eye Syndrome

Background

Dry eye syndrome (DES) is a common tear film and ocular surface disease that results in discomfort, visual disturbance, and tear film instability with potential damage to the ocular surface. Systemic diseases associated with DES include diabetes mellitus, rheumatoid arthritis, depression, anxiety, thyroid disease, allergic diseases, irritable bowel syndrome, chronic pain syndrome, and hyperlipidemia. Interestingly, it has been found that most of these are associated with low levels of serum 25-hydroxyvitamin D (25(OH)D) or inadequate sunlight exposure.

Methods

In this cross-sectional data analysis, noninstitutionalized adults aged ≥19 years (N = 17,542) who participated in Korean National Health and Nutrition Examination Survey 2010–2012 were included. Information regarding duration of sunlight exposure was collected from the survey participants. Serum 25(OH)D and zinc levels were measured. The confounding variables were age, gender, sunlight exposure time, region of residence, obesity, serum 25(OH)D level, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and walking exercise.

Results

Mean serum 25(OH)D levels of subjects with and without DES were 16.90 ± 6.0 and 17.52 ± 6.07 (p<0.001). Inadequate sunlight exposure time (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.307–1.848), urban residence (OR, 1.669; 95% CI, 1.456–1.913), indoor occupation (OR, 1.578; 95% CI, 1.389–1.814), and low serum 25(OH)D level (OR, 1.158; 95% CI, 1.026–1.308) were the risk factors for DES. After adjusting for age, sex, obesity, diabetes mellitus, rheumatoid arthritis, depression, thyroid disorder, atopic dermatitis, history of ocular surgery, regular exercise, and occupation, low serum 25(OH)D level (OR, 1.178; 95% CI, 1.010–1.372) and deficient sunlight exposure time (OR, 1.383; 95% CI, 1.094–1.749) were the risk factors for diagnosed DES.

Conclusion

Low serum 25(OH)D levels and inadequate sunlight exposure are associated with DES in Korean adults. These results suggest that sufficient sunlight exposure or vitamin D supplementation may be useful in DES treatment.

Vitamin D deficiency in patients with intestinal malabsorption syndromes--think in and outside the gut

There is a very high prevalence of vitamin D deficiency, which is defined by a serum level of 25-hydroxyvitamin D [25(OH)D] of lower than 20 ng/mL, in all populations of the world. Unfortunately, the prevalence of vitamin D deficiency in patients with intestinal malabsorption syndromes, including cystic fibrosis (CF), celiac disease (CD), short bowel syndrome and inflammatory bowel disease (IBD), is higher than that in the general population, indicating the presence of disease-specific causative factors. In this review, we aimed to present clinical findings to highlight the roles of insufficient exposure to sunlight and inflammation in the development of vitamin D deficiency in patients with intestinal malabsorption syndromes. Furthermore, we aimed to present experimental evidence that supported a role of vitamin D deficiency in the pathogenesis of IBD. Finally, we reviewed clinical intervention strategies aiming to normalize vitamin D status in and even to improve the conditions of patients and to discuss certain issues that needed to be addressed in future research.

Digestion and Postprandial Metabolism in the Elderly

The elderly are an increasing segment of the population. Despite the rapid gains in medical knowledge and treatments, older adults are more likely to experience chronic illnesses that decrease quality of life and accelerate mortality. Nutrition is a key modifiable lifestyle factor which greatly impacts chronic disease risk. Yet despite the importance of nutrition, relatively little is known of the impact of advancing age on the gastrointestinal function, the digestive responses, and the post-meal metabolic adaptations that occur in response to ingested food. Knowledge of the age-related differences in digestion and metabolism in the elderly is essential to the development of appropriate nutritional recommendations for the maintenance of optimal health and prevention of disease.

Brazilian consensus on photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

Vitamin D deficiency among Jordanian university students and employees

Purpose

– This paper aims to assess the prevalence of vitamin D deficiency among female university students and employees at the Hashemite University (HU) and, then, to identify risk factors for developing vitamin D deficiency among this population. Vitamin D deficiency remains widespread in many countries, including Jordan, and has been linked to many diseases.

Design/methodology/approach

– In this cross-sectional study, blood samples were taken from 320 healthy females – 160 students and 160 employees – aged between 18 and 65 years old who presented for routine checkup at the medical center of HU. Level of direct sun exposure and barriers to getting enough sunlight (dress style, skin color and sunscreen use) were questioned. Serum levels of 25-hydroxyvitamin D were measured, and the daily intakes of vitamin D, calcium and phosphorous were estimated through completing an adopted food frequency questionnaire. All required data were collected using a face-to-face interview by trained dietitians. The software package ESHA was used to determine the daily intake from the nutrients.

Findings

– The prevalence of vitamin D deficiency (25-OHD < 25 nmol/L) was 31.2 per cent in female students compared to 20.5 per cent in female employees. Prolonged exposure to sun was independently related to vitamin D deficiency (odds ratio = 4.55); participants exposed for 30 minutes daily were at a higher risk for vitamin D deficiency. However, estimated vitamin D intake was not affected by age and working status.

Research limitations/implications

– The present study has some important limitations. First, this study based on serum 25-OHD results, which alone, without biochemical parameters such as parathyroid hormone (either primary or secondary), might be linked to accelerated degradation of 25-OHD and shorter half-life. Second, the half-life of 25-OHD was not consistently available. Third, the smaller sample size of participants. Finally, the present study did not distinguish between intake of vitamin D2 and D3. This limitation caused the inability to precisely evaluate the prevalence of vitamin D deficiency in the studied population.

Practical implications

– This study indicates that it is crucial to create awareness concerning the daily intake of vitamin D in the community to avoid long-term complications related to vitamin D deficiency, by using urgent measures including vitamin D supplementation and fortification of some highly consumed food, milk and other dairy products. Educational endeavors about sensible sun exposure should be implemented to improve vitamin D status among this population. The findings of the present study call for action at the national level to build strategies for health promotion about vitamin D supplementation in groups at risk for low supplementation (e.g. younger female students, with previous chronic diseases and poor sun exposure), and engage these populations in strategizing for successful and demographically relevant outreach and education in their own communities along with effort to prevent obesity and diabetes as well as raising awareness through simple programs to prevent and treat vitamin D deficiency among women living in Jordan.

Originality/value

– The high prevalence of vitamin D deficiency among female university students in this study emphasizes the necessity of vitamin D supplementation and calls for action to build strategies for health promotion concerning vitamin D supplementation.

Sunscreens: a review of health benefits, regulations, and controversies

Ultraviolet radiation plays a major role in the development of nonmelanoma and melanoma skin cancers. Photoprotection by sunscreens has been shown to prevent the development of actinic keratosis, squamous cell carcinoma, melanoma, and photoaging. However, these benefits are only derived if the users apply sunscreen appropriately and practice other sun protection measures. This review discusses the health benefits provided by sunscreen use, updates the latest regulatory landscape on sunscreen, and addresses the controversies and limitations associated with sunscreen use.

Bone mineral density and factors influencing it in Asian Indian population with type 2 diabetes mellitus

OBJECTIVE

To assess bone mineral density (BMD) in type 2 diabetes mellitus (T2DM) patients and its relation, if any, to clinical, hormonal and metabolic factors.

MATERIALS AND METHODS

A prospective evaluation of 194 T2DM patients (97 men and 97 women) was carried out. BMD was done with dual energy X-ray absorptiometry (DXA) at the lumbar spine and total hip. Physical activity, nutritional intake and sunlight exposure were calculated. Biochemical and hormonal tests included serum 25 hydroxy vitamin D [25(OH) D], parathyroid hormone, estrogen, testosterone and urinary calcium-creatinine ratio. Glycosylated hemoglobin and complete lipid profiles were done in patients with diabetes. Five hundred and seventy one non-diabetic controls (262 males and 309 females) were evaluated for BMD alone.

RESULTS

BMD was normal (Z score > -2) in 156 (80.5%) and low (Z score ≤ -2) in 38 (19.5%) patients in the diabetes study group. BMD in the diabetes group was significantly higher than the control group in both sexes at the hip and spine. The difference was no longer significant on analysis of a BMI matched control subgroup. Weight and BMI showed significant correlation to BMD. Duration of T2DM, degree of glycemic control, use of drugs like statins and thiazolidinediones, 25(OH) D levels, calcium intake, sunlight exposure and physical activity did not significantly affect BMD in this cohort of individuals with diabetes.

CONCLUSIONS

Bone mineral density of Asian Indian T2DM subjects was similar to that of healthy volunteers in this study.

Determinants of vitamin D levels in children, adolescents, and young adults with juvenile idiopathic arthritis

OBJECTIVE

Deficiency of 25-hydroxyvitamin D [25(OH)D] is reported to be common in patients with rheumatoid arthritis (RA); data in patients with juvenile idiopathic arthritis (JIA) are inconsistent. We assessed serum 25(OH)D in children, adolescents and young adults with JIA, in order to identify the risk factors for vitamin D deficiency in patients with JIA.

METHODS

We evaluated 152 patients with JIA: 115 female, 37 male, mean age 16.2 ± 7.4 yrs; evaluated by onset type, 96 had oligoarticular, 35 polyarticular, 7 systemic, and 14 enthesitis-related arthritis (ERA). Patients were compared with a control group matched for sex and age. All patients and controls underwent laboratory tests of plasma 25(OH)D, parathyroid hormone (PTH), calcium, phosphorus, and bone alkaline phosphatase levels, and dual-energy x-ray absorptiometry examination.

RESULTS

Patients with JIA showed significantly reduced 25(OH)D levels compared to controls (p < 0.001), even divided into subtypes (oligoarticular, p < 0.05; polyarticular, p < 0.005; systemic, p < 0.001; ERA, p < 0.005). Patients with active disease and/or frequent relapses had significantly reduced 25(OH)D levels compared to patients with no active disease and no frequent flares (p < 0.005, respectively). Nevertheless, JIA patients had significantly higher PTH levels compared to controls (p < 0.0001). JIA patients with 25(OH)D deficiency showed a significantly lower bone mineral apparent density than those with normal 25(OH)D levels (p < 0.001).

CONCLUSION

JIA patients have reduced 25(OH)D and higher PTH values. This may explain at least in part why JIA patients, despite more effective current drugs, do not achieve bone-normal condition over time. JIA patients with more severe disease could require higher supplementation of vitamin D to maintain normal 25(OH)D serum levels. Longterm studies are needed to investigate the relationship between serum 25(OH)D levels and disease activity in JIA.

Vitamin D levels in children, adolescents, and young adults with juvenile-onset systemic lupus erythematosus: a cross-sectional study

Background

SS and LC contributed equally to this manuscript. Hypovitaminosis D is common in the general population. Although many studies on 25-hydroxyvitamin D (25(OH)D) are available on systemic lupus erythematosus (SLE), few data are reported in juvenile-onset SLE (JSLE) patients.

Design

This study aimed to assess serum 25(OH)D levels in JSLE patients and to identify risk factors for vitamin D deficiency in this population.

Methods

Forty-five Caucasian JSLE patients (36 females, nine males; mean age 18.9 ± 6.3 years) and 109 age- and sex-matched healthy controls entered the study. Dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine, serum calcium and phosphate, bone-specific alkaline phosphatase (BSAP), parathyroid hormone (PTH), and 25(OH)D were assessed. The data were compared with an age- and sex-matched control group including 109 Caucasian healthy subjects.

Results

JSLE patients exhibited lower 25(OH)D levels than controls ( p < 0.005), with the lower values observed in patients with active vs. inactive disease ( p < 0.05). JSLE patients exhibited reduced total calcium levels ( p < 0.001) and higher phosphate levels ( p < 0.001), BSAP ( p < 0.001) and PTH ( p < 0.001) than controls. In addition, JSLE patients exhibited lower spine bone mineral apparent density (BMAD) SDS values than controls ( p < 0.001), with higher values in patients with 25(OH)D sufficiency and insufficiency than in those with 25(OH)D deficiency ( p < 0.001).

Conclusions

Patients with JSLE have significantly lower 25(OH)D levels than controls. Therefore, vitamin D supplementation may be useful to normalize bone mass and quality in subjects with JSLE.

Vitamin D and bone health: Epidemiologic studies

Allelic variation in the vitamin D receptor was the first non-structural gene to be associated with osteoporosis, and together with the effects of the vitamin D system on bone homeostasis, suggested that this vitamin might have a strong role in bone health. However, controversy exists regarding what level of serum 25-hydroxyvitamin D (25(OH)D) is optimal. Current data from biochemical, observational and randomized controlled trials (RCTs), indicate serum 25(OH)D levels of at least 50 nmol l(-1) are required for normalization of parathyroid hormone (PTH) levels, to minimize the risk of osteomalacia and for optimal bone cell function. The skeletal consequences of 25(OH)D insufficiency include secondary hyperparathyroidism, increased bone turnover and bone loss and an increased risk of minimal trauma fractures. In large scale epidemiological studies, serum 25(OH)D levels are associated with bone mineral density in both men and women. However, there is mixed evidence on the effectiveness of optimizing serum 25(OH)D levels for the prevention of bone loss and minimal trauma fractures in postmenopausal women and older men. There may be some benefit on primary fracture prevention for those who have inadequate serum levels of 25(OH)D, particularly in institutionalised elderly patients, but only when combined with calcium supplements. For optimal bone health, evidence from RCTs suggests vitamin D may be considered a threshold nutrient with few further bone benefits observed at levels of 25(OH)D above which PTH is normalized. An adequate calcium intake is also imperative to gain optimum benefit from an improved vitamin D status in those with insufficient 25(OH)D levels, with an increased calcium intake being associated with suppression of PTH levels.

Vitamin D receptor expression controls proliferation of naïve CD8+ T cells and development of CD8 mediated gastrointestinal inflammation

Background

Vitamin D receptor (VDR) deficiency contributes to the development of experimental inflammatory bowel disease (IBD) in several different models. T cells have been shown to express the VDR, and T cells are targets of vitamin D. In this article we determined the effects of VDR expression on CD8⁺ T cells.

Results

VDR KO CD8⁺ T cells, but not WT CD8⁺ T cells, induced colitis in Rag KO recipients. In addition, co-transfer of VDR KO CD8⁺ T cells with naïve CD4⁺ T cells accelerated colitis development. The more severe colitis was associated with rapidly proliferating naïve VDR KO CD8⁺ T cells and increased IFN-γ and IL-17 in the gut. VDR KO CD8⁺ T cells proliferated in vitro without antigen stimulation and did not downregulate CD62L and upregulate CD44 markers following proliferation that normally occurred in WT CD8⁺ T cells. The increased proliferation of VDR KO CD8⁺ cells was due in part to the higher production and response of the VDR KO cells to IL-2.

Conclusions

Our data indicate that expression of the VDR is required to prevent replication of quiescent CD8⁺ T cells. The inability to signal through the VDR resulted in the generation of pathogenic CD8⁺ T cells from rapidly proliferating cells that contributed to the development of IBD.

Determinants of Vitamin D Levels in Italian Children and Adolescents: A Longitudinal Evaluation of Cholecalciferol Supplementation versus the Improvement of Factors Influencing 25(OH)D Status

Objective. This paper aims to assess 25(OH)D levels in Italian children and adolescents identifying risk factors for 25(OH)D deficiency and to evaluate whether a normal 25(OH)D value can be restored in 25(OH)D-deficient patients. Methods. We evaluated 25(OH)D levels in 679 Italian children and adolescents (≤10, 11-20, 21-30, and >30 ng/mL were defined as severe deficiency, deficiency, insufficiency, and sufficiency, resp.). Of these, 365 25(OH)D-deficient were followed up for 1 year; 205 were treated with cholecalciferol (Arm A: 400 I.U.) and 160 by improving the environmental variables influencing 25(OH)D levels (Arm B). Results. At cross-sectional evaluation, 11.3% showed sufficiency, 30.0% insufficiency, and 58.7% 25(OH)D deficiency. Mean 25(OH)D was 19.08 ± 8.44 ng/mL. At the enrollment time (T 0), no difference was found between Arms A and B with respect to distribution and 25(OH)D levels. At end time (T 1) 26.0% (29.7% in Arm A versus 20.6% in Arm B) showed sufficiency, 38.4% (42.0% versus 34.4%) insufficiency, and 35.6% (28.3% versus 45.0%) 25(OH)D deficiency. Mean 25(OH)D level was 23.71 ± 6.83 ng/mL. Conclusions. Neither changes of lifestyle nor 400 I.U. cholecalciferol supplementation alone appears to be sufficient to restore adequate 25(OH)D levels.

Variation of vitamin D in cow's milk and interaction with β-lactoglobulin

Vitamin D is the collective name for a group of closely related lipids, whose main biological function is to maintain serum calcium and phosphorus concentrations within the normal range by enhancing the efficiency of the small intestine to absorb these minerals from the diet. We used a commercially available ELISA method for the determination of vitamin D in bovine milk. Individual milk samples from two different Italian Friesian herds were analysed. The enzyme immunoassay method used was confirmed as a useful tool to measure the vitamin D in the milk as it greatly reduces the time required to perform the conventional HPLC analysis. An interesting variation was found among individual animals that may be associated with management factors and specific genetic effects. A relationship was highlighted between vitamin D and the genetic polymorphism of β-lactoglobulin, the main bovine whey protein which is involved in the transport of small hydrophobic molecules such as retinol and vitamin D. The relatively high content of vitamin D in most milk samples suggests an opportunity to improve the natural content of vitamin D in milk either by acting on the herd management or selecting individuals genetically predisposed to produce milk with a higher vitamin D content.

Vitamin D status among older community dwelling men living in a sunny country and associations with lifestyle factors: the Concord Health and Ageing in Men Project, Sydney, Australia

OBJECTIVES

Inadequate vitamin D status (25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L) is an increasingly important public health issue in Australia. The aim of this analysis is to describe 25(OH)D levels in community dwelling men aged ≥70 years in Sydney, Australia, and to determine associations between serum 25(OH)D levels and socioeconomic and lifestyle factors.

DESIGN

A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007.

PARTICIPANTS

1659 non-institutionalised men aged ≥70 years.

METHODS

The cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007. Participants included 1659 community dwelling men who were interviewed and had clinical assessments. Main outcome measurements included serum 25(OH)D levels measured in blood samples using a radioimmunoassay kit (DiaSorin Inc., Stillwater, MN). Covariates included age, socioeconomic measures, season of blood sample, physical activity, sun exposure, vitamin D supplement use, cigarette smoking status, alcohol consumption, obesity and measures of health.

RESULTS

Prevalence of vitamin D insufficiency was 43.0%; highest in winter (55.5%) and spring (53.9%), and was associated with season (winter and spring), low physical activity, avoidance of sun exposure, current smoking and obesity, even after adjustment for confounding factors.

CONCLUSION

Inadequate vitamin D status is highly prevalent among Australian older men and is associated with specific lifestyle factors. These findings emphasize the need to screen and monitor 25(OH)D levels in this population group, despite living in a sunny country such as Australia.

Sunlight exposure and breast density: a population-based study

Purpose

This study aims to assess the association of sunlight exposure with breast cancer risk, measured by the breast density assessed from Tabár's mammographic pattern in Chinese women.

Methods

A total of 676 premenopausal women were recruited to participate in this study, in which 650 completed a validated sunlight exposure questionnaire via telephone. The mammograms were classified according to Tabár's classification for parenchyma, and patterns IV & V and I, II & III indicated respectively high and low risk mammographic patterns for breast cancer. The odds ratios (OR) and 95% confidence intervals (CIs) for sun exposure-related variables were estimated using unconditional logistic regression with adjustment for potential confounders.

Results

Among 646 participants, women with high breast cancer risk (Tabár's patterns IV &V) had less hours spent in the sun than those with low risk (I, II & III) at any age stage. A higher level of sunlight exposure was associated with a significantly lower risk having high risk Tabár's pattern. Women aged 40 to 44 years who were in the highest tertile of lifetime total hours spent in the sun had a multi-adjusted OR of 0.41 (95% CI, 0.18-0.92; p for trend=0.03) compared with those in the lowest tertile (>2.19 hr/day vs. <1.32 hr/day). For hours spent in the sun across the ages of 6 to 12 years, the comparable OR was 0.37 (95% CI, 0.15-0.91; p for trend=0.03).

Conclusion

These findings suggest that higher sunlight exposure is related to a lower risk of having high risk breast density pattern in premenopausal women. Our results also suggest the most relevant period of exposure is during earlier life.

Vitamin D (25OHD) Serum Seasonality in the United States

Background

Vitamin D is an important micronutrient for health. Hypovitaminosis D is thought to play a role in the seasonality of a number of diseases and adverse health conditions. To refine hypotheses about the links between vitamin D and seasonal diseases, good estimates of the cyclicality of serum vitamin D are necessary.

Objectives

The objective of this study is to describe quantitatively the cyclicality of 25-hydroxyvitamin D (25OHD) in the United States. We provide a statistical analysis with weekly time resolution, in comparison to the quarterly (winter/spring/summer/fall) estimates already in the literature.

Methods

We analyzed time series data on 25OHD, spanning 287 consecutive weeks. The pooled data set comes from 3.44 million serum samples from the United States. We statistically analyzed the proportion of sera that were vitamin D sufficient, defined as 25OHD ng/mL, as a function of date.

Results

In the United States, serum 25OHD follows a lagged pattern relative to the astronomical seasons, peaking in late summer (August) and troughing in late winter (February). Airmass, which is a function of solar altitude, fits the 25OHD data very well when lagged by 8 weeks.

Conclusions

Serum vitamin D levels can be modeled as a function of date, working through a double-log transformation of minimal solar airmass (easily calculated from solar altitude, retrievable from an online solar altitude/azimuth table).

Chronic kidney disease and diabetes mellitus predict resistance to vitamin D replacement therapy

BACKGROUND

25-Hydroxyvitamin D [25(OH)D] is a marker of nutritional status; however, chronic kidney disease (CKD) results in alterations in vitamin D metabolism, including the loss of vitamin D-binding proteins and alterations in CYP27B1 and CYP24 enzymes that metabolize 25(OH)D. This study was designed to determine the predictors of responsiveness to correction of vitamin D deficiency with oral vitamin D2 (ergocalciferol) in adults.

METHODS

A retrospective study of 183 veterans with 25(OH)D level <30 ng/mL, who were treated with 50,000 IU per week of vitamin D2, was performed. Logistic regression models were developed to determine the factors predicting the response to treatment, defined as either the change in serum 25(OH)D level/1000 IU of vitamin D2 or the number of vitamin D2 doses (50,000 IU per dose) administered.

RESULTS

The mean age of the patients was 63 ± 12 years. About 87% were men and 51% diabetic, and 29% had an estimated glomerular filtration rate of <60 mL/min/1.73 m. The average number of vitamin D2 doses was 10.91 ± 5.95; the average increase in 25(OH)D level was 18 ± 10.80 ng/mL. 25(OH)D levels remained <30 ng/mL in 61 patients after treatment. A low estimated glomerular filtration rate and the presence of diabetes mellitus were significant independent predictors for inadequate response to vitamin D2 treatment in logistic regression models. Patients with CKD required greater amounts of vitamin D2 to achieve similar increases in 25(OH)D levels, versus non-CKD patients.

CONCLUSIONS

The presence of CKD and diabetes mellitus is associated with resistance to correction of 25(OH)D deficiency with vitamin D2 therapy. The underlying mechanism needs to be evaluated in prospective studies.

Vitamin D content of food and its contribution to vitamin D status: a brief overview and Australian focus

There are only a few natural foods that contain nutritionally significant quantities of vitamin D. These include egg yolk, some fatty fish, and in much lower concentrations, meat. The published values of the vitamin D content of food are summarised here and their contribution to dietary vitamin D intake is discussed, with particular reference to Australia. Dietary vitamin D is unlikely to reach the level recommended by the US Institute of Medicine. It is therefore concluded that dietary vitamin D will only be a component of vitamin D supply, with UV exposure and/or oral supplements continuing to be the main sources of vitamin D to maintain adequate status.

Vitamin D supplementation in older adults: searching for specific guidelines in nursing homes

BACKGROUND

The prevalence of vitamin D insufficiency is very high in the nursing home (NH) population. Paradoxically, vitamin D insufficiency is rarely treated despite of strong clinical evidence and recommendations for supplementation. This review aims at reporting the current knowledge of vitamin D supplementation in NH and proposing recommendations adapted to the specificities of this institutional setting.

DESIGN

Current literature on vitamin D supplementation for NH residents was narratively presented and discussed by the French Group of Geriatrics and Nutrition.

RESULT

Vitamin D supplementation is a safe and well-tolerated treatment. Most residents in NH have vitamin D insufficiency, and would benefit from vitamin D supplement. However, only few residents are actually treated. Current specific and personalized protocols for vitamin D supplementation may not be practical for use in NH settings (e.g., assessment of serum vitamin D concentrations before and after supplementation). Therefore, our group proposes a model of intervention based on the systematic supplementation of vitamin D (1,000 IU/day) since the patient's admission to the NH and throughout his/her stay without the need of a preliminary evaluation of the baseline levels. Calcium should be prescribed only in case of poor dietary calcium intake.

CONCLUSION

A population-based rather than individual-based approach may probably improve the management of vitamin D insufficiency in the older population living in NH, without increasing the risks of adverse health problems. The clinical relevance and cost effectiveness of this proposal should be assessed under NH real-world conditions to establish its feasibility.

Seasonal changes in vitamin D status among Danish adolescent girls and elderly women: the influence of sun exposure and vitamin D intake

BACKGROUND/OBJECTIVES

To determine seasonal variation in vitamin D status in healthy Caucasian adolescent girls and elderly community-dwelling women living in Denmark, and to quantify the impact of sun exposure and intake on the seasonal changes in vitamin D status.

SUBJECTS/METHODS

A 1-year longitudinal observational study of 54 girls (11-13 years) and 52 women (70-75 years). The participants were examined three times (winter-summer-winter). Serum 25-hydroxyvitamin D (S-25OHD) concentration and vitamin D intake were measured at each visit. Sun exposure was measured during summer.

RESULTS

S-25OHD concentrations (winter, summer, winter) were median (25, 75 percentiles) 23.4 (16.5, 36.4), 60.3 (42.7, 67.7), 29.5 (22.2, 40.4) and 47.2 (27.3, 61.1), 67.3 (35.1, 79.2), 50.5 (32.7, 65.5)nmol/l for girls and women, respectively. The usual sun habits were determinant (P=0.002) for change in vitamin D status from winter to summer. Vitamin D intake from supplements (P<0.0001) and diet (P=0.002) were determinants for change in vitamin D status from summer to winter. Winter vitamin D status of 50 nmol/l is achievable when vitamin D status the previous summer was ≈ 100 nmol/l. If summer vitamin D status is only ≈ 60 nmol/l, vitamin D status the following winter would be ≈ 28 nmol/l.

CONCLUSIONS

Low vitamin D status among adolescent girls and elderly women during two consecutive winter seasons, improved vitamin D status during the summer and better vitamin D status in women than in girls was found. The estimations show that a summer S-25OHD concentration ≈ 100 nmol/l is needed to achieve a concentration of ≈ 50 nmol/l the following winter.

Vitamin D in cutaneous carcinogenesis: part I

Skin cancer is the most common cancer in the United States. Exposure to ultraviolet radiation is a known risk factor for skin cancer but is also the principal means by which the body obtains vitamin D. Several studies have suggested that vitamin D plays a protective role in a variety of internal malignancies. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar protective effect. These noncalcemic actions of vitamin D have called into question whether the current recommended intake of vitamin D is too low for optimal health and cancer prevention. Part I will review the role of vitamin D in the epidermis; part II will review the role of vitamin D in keratinocyte-derived tumors to help frame the discussion on the possible role of vitamin D in the prevention of skin cancer.

BMI but Not Race Contributes to Vitamin D-Parathyroid Hormone Axis in Peripubertal Girls

Currently, there is widespread interest in establishing 25-hydroxy vitamin D (25OHD) level preventing a secondary elevation in parathyroid hormone (PTH). The aim of this study was to identify the 25OHD nadir resulting in a rise of PTH and to determine if this inflection point is weight- or race-specific during growth and development in peripubertal girls. A total of 104 normal (n = 61) and overweight (n = 43) African American (AA) and European American (EA) girls, 5 to 14 years of age, were included. Though AAs had lower 25OHD levels, there was no difference in PTH compared with EAs. A 25OHD concentration of 27.2 ng/mL (P < .01) was indicated to increase PTH in normal-weight girls, although a statistically significant level was not established in overweight girls. No race difference in inflection point was observed. These data suggest a potential influence of weight status on the 25OHD-PTH inflection point in peripubertal girls. Accordingly, on determination of 25OHD level reflecting optimal health, consideration of weight status appears to be important during this critical period of growth and development.

Vitamin D: The "sunshine" vitamin

Vitamin D insufficiency affects almost 50% of the population worldwide. An estimated 1 billion people worldwide, across all ethnicities and age groups, have a vitamin D deficiency (VDD). This pandemic of hypovitaminosis D can mainly be attributed to lifestyle (for example, reduced outdoor activities) and environmental (for example, air pollution) factors that reduce exposure to sunlight, which is required for ultraviolet-B (UVB)-induced vitamin D production in the skin. High prevalence of vitamin D insufficiency is a particularly important public health issue because hypovitaminosis D is an independent risk factor for total mortality in the general population. Current studies suggest that we may need more vitamin D than presently recommended to prevent chronic disease. As the number of people with VDD continues to increase, the importance of this hormone in overall health and the prevention of chronic diseases are at the forefront of research. VDD is very common in all age groups. As few foods contain vitamin D, guidelines recommended supplementation at suggested daily intake and tolerable upper limit levels. It is also suggested to measure the serum 25-hydroxyvitamin D level as the initial diagnostic test in patients at risk for deficiency. Treatment with either vitamin D2 or vitamin D3 is recommended for deficient patients. A meta-analysis published in 2007 showed that vitamin D supplementation was associated with significantly reduced mortality. In this review, we will summarize the mechanisms that are presumed to underlie the relationship between vitamin D and understand its biology and clinical implications.

Role of medicinal plants and natural products on osteoporotic fracture healing

Popularly known as “the silent disease” since early symptoms are usually absent, osteoporosis causes progressive bone loss, which renders the bones susceptible to fractures. Bone fracture healing is a complex process consisting of four overlapping phases—hematoma formation, inflammation, repair, and remodeling. The traditional use of natural products in bone fractures means that phytochemicals can be developed as potential therapy for reducing fracture healing period. Located closely near the equator, Malaysia has one of the world's largest rainforests, which are homes to exotic herbs and medicinal plants. Eurycoma longifolia (Tongkat Ali), Labisia pumila (Kacip Fatimah), and Piper sarmentosum (Kaduk) are some examples of the popular ethnic herbs, which have been used in the Malay traditional medicine. This paper focuses on the use of natural products for treating fracture as a result of osteoporosis and expediting its healing.