Dietary vitamin-D Research Articles

Fat Distribution as a Determinant of Vitamin D Status: A Cross-Sectional Study of Adults in the United States

Background: This study aimed to elucidate correlations between obesity-related indicators and vitamin D (VD) status in a nationally representative sample of U.S. adults. Methods: We analysed data from 9168 adults aged 20–59 years obtained from the 2011–2018 National Health and Nutrition Examination Survey. Serum 25 hydroxyvitamin D [25(OH)D] levels were measured and categorised into quartiles. Anthropometric measurements, including weight, waist circumference, and fat mass in various body regions quantified through dual-energy X-ray absorptiometry, were collected. Multiple imputation was employed to replace missing data. The importance of obesity-related indicators and serum 25(OH)D concentration was explored using multiple linear regression adjusted for demographics, lifestyle factors, dietary intake, and clinical biomarkers, and stepwise regression. Results: Weight, waist circumference, and fat mass across all body regions were inversely associated with serum 25(OH)D levels (all p < 0.001). Notable differences were observed between men and women. Stepwise regression revealed a strong inverse correlation between visceral adipose tissue and serum 25(OH)D concentration in men [β 95% CI: –13.04 (–18.10, –7.99), p < 0.001], whereas in women, only weight was significantly correlated with serum 25(OH)D concentration [β 95% CI: –0.20 (–0.28, –0.12), p < 0.001]. Demographic attributes, seasonal sunlight exposure, dietary VD, calcium, phosphorus, and magnesium intake, and biomarkers including alkaline phosphatase and creatinine also emerged as significant predictors. Conclusions: Besides conventional obesity measures, abdominal fat metrics exhibit robust associations with VD deficiency, especially in men. Public health initiatives and clinical management strategies for hypovitaminosis D in obese populations should consider nuanced aspects of adiposity distribution alongside other demographic, lifestyle, and dietary factors influencing VD.

Vitamin D Maintains Growth and Bone Mineral Density against a Background of Severe Vitamin A Deficiency and Moderate Toxicity in a Swine Model.

Excessive vitamin A (VA) negatively impacts bone. Interactions between VA and vitamin D (VD) in bone health are not well-understood. This study used a traditional two-by-two factorial design. Pigs were weaned and randomized to four treatments (n = 13/group): -A-D, -A+D, +A-D, and +A+D for 3 and 5 wk. Serum, liver, kidney, adrenal glands, spleen, and lung were analyzed by ultra-performance LC. Growth was evaluated by weight measured weekly and BMD by DXA. Weights were higher in -A+D (18.1 ± 1.0 kg) and +A+D (18.2 ± 2.3 kg) at 5 wk than in -A-D (15.5 ± 2.1 kg) and +A-D (15.8 ± 1.5 kg). Serum retinol concentrations were 0.25 ± 0.023, 0.22 ± 0.10, 0.77 ± 0.12, and 0.84 ± 0.28 µmol/L; and liver VA concentrations were 0.016 ± 0.015, 0.0065 ± 0.0035, 2.97 ± 0.43, 3.05 ± 0.68 µmol/g in -A-D, -A+D, +A-D, and +A+D, respectively. Serum 25(OH)D3 concentrations were 1.5 ± 1.11, 1.8 ± 0.43, 27.7 ± 8.91, and 23.9 ± 6.67 ng/mL in -A-D, +A-D, -A+D, +A+D, respectively, indicating a deficiency in -D and adequacy in +D. BMD was highest in +D (p < 0.001). VA and the interaction had no effect on BMD. Dietary VD influenced weight gain, BMD, and health despite VA status.

New perspectives on the role of vitamin D in the mucosal barrier system of fish gills infected with Flavobacterium columnare

The mucosal barrier of vertebrates comprises a unique array of physical elements and bioactive molecules that act in concert to protect the host against pathogens. Vitamin D (VD), an essential nutrient for animals, along with its receptor (VDR), plays a major role in immunity. However, the correlation between VD/VDR and the mucosal barrier system remains unclear. Here, we employed the fish gill as a model and evaluated the role of VD as a dietary supplement in modifying this typical mucosal barrier system. Varies levels of VD (15.2, 364.3, 782.5, 1167.9, 1573.8, and 1980.1 IU/kg) were formulated and fed to grass carp (Ctenopharyngodon idella) for 70 d. Subsequently, fish were challenged with Flavobacterium columnare, a pathogen in epithelial tissues. Following infection, dietary VD alleviated gill rot and damage caused by F. columnare. Further investigations demonstrated that VD improved physical barrier function by elevating the antioxidant capacity and tight junction barriers, and moderated excessive apoptosis. The promoted physical barrier function was related to nuclear factor E2-related factor 2 and myosin light-chain kinase signaling. Additionally, VD treatment enhanced the immune barrier function by boosting disease resistance, producing antibacterial compounds and immunoglobulins, downregulating pro-inflammatory cytokines, and upregulating the gene expression of anti-inflammatory cytokines, which correlated with nuclear factor kappa B and the target of rapamycin signaling pathways. Thus, VD strengthened pathogen defenses in the gill mucosal barrier system. This finding supports the rationale for VD intervention in infectious diseases and will be critical for the viability of sustainable practices in aquaculture.

Effects of different dietary vitamin D combinations during the grower phase and the feed restriction phase on growth performance and sternal morphology, mineralization, and related genes expression of bone metabolism in Pekin ducks

Our study aimed to investigate the effects of different dietary vitamin D (VD) combinations during the grower (1-32 d of age) and feed restriction (33-52 d of age) phases on growth performance. We also evaluated sternal morphology, mineralization, and related genes expression of bone metabolism as well as absorption of calcium and phosphorous in duodenal mucosa and kidney in Pekin ducks. During the grower phase, we used 2 VD regimes (Group A: 3,160 IU/kg VD3; Group B: 400 IU/kg VD3 + 69 μg/kg 25-OH-D3). Each dietary treatment had 50 replicate pens of 10 ducks per pen. During the feed restriction phase, 30 replicate pens selected from Group A and Group B, repetitively, were redivided into 5 different dietary VD regimes to form a 2 × 5 experimental design. Each group consisted of 6 replicates, each with 10 ducks. During the feed restriction phase, we evaluated 5 different dietary VD combinations were as follows: T1: 2,000 IU/kg VD3 ; T2: 5,000 IU/kg VD3; T3: 3,620 IU/kg VD3 + 34.5 μg/kg 25-OH-D3; T4: 2,240 IU/kg VD3 + 69 μg/kg 25-OH-D3; T5: 1,800 IU/kg VD3 + 80 μg/kg 25-OH-D3). Results showed that Group B combinations with T5 had a better growth performance and breast meat deposition (P < 0.1). Regardless of 5 dietary VD regimes during the feed restriction phase, Group B significantly increased (P < 0.05) 52 d sternal depth and tended to increase (P < 0.1) 52 d sternal defatted weight, ash content, and phosphate (P) content of ducks. A significant interactive effect (P < 0.05) was observed on the mRNA abundance of DMP1 and Sost1 as well as RANKL/OPG in sternum and of VDR in duodenal mucosa of ducks at 52 d of age between dietary VD combinations during 2 phases. These results indicated that dietary VD regimes during the grower phase could affect the effectiveness of dietary VD regimes during the feed restriction phases; Dietary VD combinations of both phases could affect the genes expression of bone formation and the absorption as well as reabsorption of calcium and phosphorus in duodenum and kidney.

Prevalence and predictors of vitamin D deficiency among hospital staff in tertiary care center: a cross sectional study

Background: Vitamin D deficiency (VDD) is prevalent across all age groups in general population not sparing the health care workers. This study aimed to assess the prevalence and risk factors of VDD among the hospital workers of tertiary care center in Kashmir valley. Methods: In this cross-sectional study, a total of 216 apparently healthy subjects were screened for VDD from three groups, group A- minimal sunlight exposure (office employees), group B- moderate sunlight exposure (nursing students) and group C- abundant sunlight exposure (gardeners). Serum calcium, phosphorus, alkaline phosphatase, 25-hydroxy vitamin D [25(OH)D], PTH levels and urine calcium/creatinine was assessed in all subjects. Dietary assessment of vitamin D (VD) and calcium intake was done using three days dietary recall. The percent body surface area (BSA) exposed to sunshine was estimated by applying the Wallace rule of nine. Results: Serum 25(OH)D level was found to be lower in group A (17.29±10.87) as compare to group B (21.78±16.37) and group C (26.40±15.59). Prevalence of VDD was 71.6%, 70.6% and 50% in group A, group B and group C respectively. VDD was more prevalent in females and risk increased with age and BMI, decreased with duration of daily sunlight exposure, percentage BSA and dietary VD intake. Conclusions: Burden of VDD is high among hospital workers despite their direct contact with healthcare. Strategies should be made to screen them regularly and supplementation of VD should be provided to effectively counteract VDD.

Dietary vitamin D intake and sun exposure are not associated with type 1 diabetic schoolchildren and adolescents: A first report in Algeria1

BACKGROUND: A large number of children and adolescents worldwide suffer from physiological vitamin D (VD) deficiency, which has been associated with sun exposure and, consequently, the risk of developing various autoimmune diseases, including type 1 diabetes (T1D). However, the association of the disease with VD intake and sun exposure has yet to be explored. MATERIALS AND METHODS: We conducted a food frequency questionnaire and a 24-hour food recall survey, using “Ciqual table 2016” in 335 type 1 diabetic and age- and gender-matched healthy Algerian school children and adolescents from sunny Saharan and relatively less sunny Northern regions, aged between 5 and 19 years. RESULTS: Both dietary VD intake and VD levels were similar in T1D patients when comparing northern and southern regions (for both comparisons, p &gt; 0.05). Neither sun exposure nor VD intake was associated with the disease (respectively, relative risk [RR] = 1.050, p = 0.680; RR = 1.082, p = 1.000. For Cochran and Mantel-Haenszel analysis; RR = 0.841, p = 0.862). VD intake showed a significant difference between diabetics and non-diabetics in the sunny region (p = 0.022). Additionally, significant differences were found between normal and T1D schoolboys (p = 0.038), and when comparing the two groups according to the dry areas (p = 0.016). Moreover, in contrast to circulating VD levels, which were lower in T1D patients than in healthy controls, those of VD intake were significantly higher (p &lt; 0.05), especially in male patients and in those with balanced diet, low protein or carbohydrate consumption, specific food intolerances, and regular meals (p &lt; 0.05), as well as in patients with a moderate or low consumption of cooked meals or steamed foods (p &lt; 0.01). Conversely, VD intake was markedly lower in type 1 diabetics than in controls for dry and sunny areas, including the region of Adrar, as well as for consumption of low-fat foods and eggs (p &lt; 0.05 for all comparisons). Nevertheless, the relative risk of sun exposure and dietary vitamin D intake according to the World Health Organization (WHO) standard did not show a significant association with T1D (common Mantel-Haenszel estimation, RR = 0.841, 95% CI 0.118–5.973, p &gt; 0.05). CONCLUSIONS: T1D does not appear to be associated with VD intake and sun exposure in the Algerian Sahara region. Therefore, the consumption of VD in T1D patients in the Algerian Sahara would suspect that its association with the disease would be related to its synthesis alteration.

Impact of dietary vitamin D on immunoregulation and disease pathology in lupus-prone NZB/W F1 mice.

Vitamin D (VD) deficiency is a highly prevalent worldwide phenomenon and is extensively discussed as a risk factor for the development of systemic lupus erythematosus (SLE) and other immune-mediated diseases. In addition, it is now appreciated that VD possesses multiple immunomodulatory effects. This study aims to explore the impact of dietary VD intake on lupus manifestation and pathology in lupus-prone NZB/W F1 mice and identify the underlying immunological mechanisms modulated by VD. Here, we show that low VD intake accelerates lupus progression, reflected in reduced overall survival and an earlier onset of proteinuria, as well higher concentrations of anti-double-stranded DNA autoantibodies. This unfavorable effect gained statistical significance with additional low maternal VD intake during the prenatal period. Among examined immunological effects, we found that low VD intake consistently hampered the adoption of a regulatory phenotype in lymphocytes, significantly reducing both IL-10-expressing and regulatory CD4+ T cells. This goes along with a mildly decreased frequency of IL-10-expressing B cells. We did not observe consistent effects on the phenotype and function of innate immune cells, including cytokine production, costimulatory molecule expression, and phagocytic capacity. Hence, our study reveals that low VD intake promotes lupus pathology, likely via the deviation of adaptive immunity, and suggests that the correction of VD deficiency might not only exert beneficial functions by preventing osteoporosis but also serve as an important module in prophylaxis and as an add-on in the treatment of lupus and possibly other immune-mediated diseases. Further research is required to determine the most appropriate dosage, as too-high VD serum levels may also induce adverse effects, possibly also on lupus pathology.

Influence of Vitamin D Supplement on Immune Function of the Older Healthy People: A Pilot Randomised Control Trial

Abstract Objectives The study aims to investigate the influence of vitamin D (VD) supplement on immune function of the healthy older people. Methods Designed as a randomized control trial, 21 participants (55–85) years old took part and completed the study (20 White, 1 Indian) during May-November 2018 in Coventry, England. The participants were randomized into two groups, VD and control, stratified by age, gender and body mass index (BMI). The VD group (n = 11) took VD3 of 25 μg/day for 12 weeks, while the control group (n = 9) were only provided with educational information of VD. At baseline, 6 weeks and 12 weeks, plasma 25(OH)D levels and immune parameters including phagocytic activity of granulocytes and monocytes, tumour necrosis factor (TNF), interleukin 6 (IL-6), lymphocyte subsets (Th, Tc and natural killer cells), and fast blood glucose and lipid were measured. Dietary VD intake was analysed at baseline and week 12. The data were presented as mean ± standard error (SE) and analysed by two-way repeated measures ANOVA. Results The average age of the participants was (65.8 ± 1.7) years old (67.4 ± 2.7 in VD group and 64.5 ± 2.2 in control group). At baseline, 42.9% of the participants were VD deficiency (25(OH)D &amp;lt; 30 nmol/L), only 10% achieved a level of 25(OH)D &amp;gt; 50 nmol/L. There was a significant increase in plasma 25(OH)D concentration in VD group compared with that in the control group (visit*treatment effect p = 0.002). The level of 25(OH)D in the VD group was increased rapidly at 6 weeks (from 38.4 ± 8.7 nmol/L at baseline to 51.0 ± 9.3 nmol/L) and little change has been observed at 12 weeks (51.8 ± 8.6 nmol/L). There was a significant visit*treatment effect (p = 0.036) on the plasma creatinine concentration between two groups, indicating a decrease of plasma creatinine concentration in VD group (from 79.8 ± 7.0 μmol/L at baseline to 75.1 ± 5.4 μmol/L at week 12). There was a significant correlation between body mass index (BMI) and 25(OH)D concentration (P &amp;lt; 0.001). There was no significant effect of VD supplementation on parameters of immune function. Conclusions VD deficiency is common among this older population even during the summertime. VD supplementation at 25 μg/day for 12 weeks showed an anti-inflammatory effect. Funding Sources Coventry University.

Vitamin D promotes growth, feed utilization and gene expression related to lipid metabolism for juvenile Orange-spotted grouper Epinephelus coioides

This study aimed to evaluate vitamin D (VD) levels on growth, feed utilization, enzymatic activity in lipid metabolism and mRNA expression for juvenile Orange-spotted grouper Epinephelus coioides (initial weight:7.40 ± 0.03 g) for 8 weeks. Six group fishes were fed diets containing different VD levels (0, 500, 1000, 2000, 4000, and 10,000 IU/kg, respectively). Compared to the control group, the weight gain rate and feed utilization rate showed a significant increase and then decreased (P < 0.05). The highest activities of alkaline phosphatase and superoxide dismutase were observed in the groups supplemented with 4000 and 1000 IU/kg VD, respectively (P < 0.05). With VD increased, triglyceride content gradually decreased (P < 0.05), whereas high-density lipoprotein content initially increased and then decreased. By comparison, cholesterol and low-density lipoprotein contents were not affected by VD supplementation levels (P > 0.05). VD supplementation levels significantly reduced liver fatty acid synthase activity (P < 0.05), but significantly promoted lipoprotein lipase and hepatic lipase activities (P < 0.05). As VD increased, liver VD deposition increased significantly in the 2000 IU/kg group. Fatty acid synthase (fas) mRNA expression was significantly down-regulated and then up-regulated (P < 0.05), whereas hepatic lipase (hl) mRNA expression levels exhibited the opposite trend. In summary, based on the broken-line regression analysis of WGR and dietary VD levels, the optimal dietary VD requirement was 930 IU/kg VD for juvenile Orange-spotted grouper Epinephelus coioides. A diet with a VD supplement from 1000 to 2000 IU/kg significantly improved the lipid metabolism in the liver for juvenile Orange-spotted grouper Epinephelus coioides, reducing fat deposition in the liver.

The Association between Vitamin D and Gut Microbiota: A Systematic Review of Human Studies.

Recent evidence has shown a number of extra-skeletal functions of Vitamin D (VD), primarily involving the immune system. One of these functions is mediated by the modulation of gut microbiota, whose alterations are linked to many diseases. Our purpose is to contribute to the understanding of existing evidence on the association between VD and gastrointestinal microbiota alterations. A systematic review of studies with human subjects has been conducted up to January 2021. We included publications reporting the association between gut microbiota and VD, including VD supplementation, dietary VD intake and/or level of 25(OH)D. We identified 25 studies: 14 were interventional and 11, observational. VD supplementation was found to be associated with a significant change in microbiome composition, in particular of Firmicutes, Actinobacteria and Bacteroidetes phyla. Furthermore, Firmicutes were found to be correlated with serum VD. Concerning alpha and beta diversity, a high nutritional intake of VD seems to induce a shift in bacterial composition and/or affects the species’ richness. Veillonellaceae and Oscillospiraceae families, in the Firmicutes phylum, more frequently decreased with both increasing levels of 25(OH)D and vitamin D supplementation. We found evidence of an association, even though the studies are substantially heterogeneous and have some limitations, resulting sometimes in conflicting results. To further understand the role of VD on the modulation of the gastrointestinal microbiota, future research should be geared toward well-designed animal-based studies or larger randomized controlled trials (RCTs).

Association of Dietary Vitamin D Intake, Serum 25(OH)D3, 25(OH)D2 with Cognitive Performance in the Elderly.

Background: As life expectancy increases, cognitive performance decline in the elderly has become one of the major global challenges. We aimed to evaluate the association of dietary vitamin D (VD), serum 25-hydroxyvitamin D3 (25(OH)D3), 25-hydroxyvitamin D2 (25(OH)D2), and total 25-hydroxyvitamin (25(OH)D) concentration with cognitive performance in older Americans. Methods: The data from the National Health and Nutrition Examination Survey (NHANES), 2011–2014 was used. The cognitive performance was assessed by the Consortium to Establish a Registry for Alzheimer’s Disease (CERAD) Word Learning sub-test, Animal Fluency test, and Digit Symbol Substitution Test (DSST). A binary logistic regression model was applied to evaluate the association between VD and cognitive performance, and restricted cubic spline model was adopted to evaluate the dose–response relationship. Results: While comparing to the lowest dietary VD intake group, the multivariate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of the highest dietary VD intake group were 0.51 (0.36–0.72) for the Animal Fluency test score and 0.45 (0.31–0.66) for DSST score, respectively; and those of serum total 25(OH)D and 25(OH)D3 concentration were 0.68 (0.47–0.97) and 0.62 (0.44–0.86) for DSST score. L-shaped relationships were identified for dietary VD intake, serum total 25(OH)D and 25(OH)D3 concentration with cognition performance. The associations between dietary VD intake, serum total 25(OH)D and cognitive performance were non-significant when stratified by gender. Conclusions: The study indicates that dietary VD intake, serum total 25(OH)D and 25(OH)D3 concentration were positively associated with cognitive performance. Further studies are needed to clarify the possible effects of dietary VD intake and serum 25(OH)D2, 25(OH)D3 on cognitive performance.

Dietary and serum vitamin D and preeclampsia risk in Chinese pregnant women: a matched case-control study.

The effect of vitamin D (VD) on the risk of preeclampsia (PE) is uncertain. Few of previous studies focused on the relationship between dietary VD intake and PE risk. Therefore, we conducted this 1:1 matched case-control study to explore the association of dietary VD intake and serum VD concentrations with PE risk in Chinese pregnant women. A total of 440 pairs of participants were recruited during March 2016 to June 2019. Dietary information was obtained using a seventy-eight-item semi-quantitative FFQ. Serum concentrations of 25(OH)D2 and 25(OH)D3 were measured by liquid chromatography-tandem MS. Multivariate conditional logistic regression was used to estimate OR and 95 % CI. Restricted cubic splines (RCS) were plotted to evaluate the dose-response relationship of dietary VD intake and serum VD concentrations with PE risk. Compared with the lowest quartile, the OR of the highest quartile were 0·45 (95 % CI 0·29, 0·71, Ptrend = 0·001) for VD dietary intake and 0·26 (95 % CI 0·11, 0·60, Ptrend = 0·003) for serum levels after adjusting for confounders. In addition, the RCS analysis suggested a reverse J-shaped relationship between dietary VD intake and PE risk (P-nonlinearity = 0·02). A similar association was also found between serum concentrations of total 25(OH)D and PE risk (P-nonlinearity = 0·02). In conclusion, this study provides evidence that higher dietary intake and serum levels of VD are associated with the lower risk of PE in Chinese pregnant women.

Higher Protein Intake Does Not Potentiate Skeletal Muscle Vitamin D Receptor

Abstract Objectives The loss of muscle mass with age increases not only risk of functional impairment, but also development and exacerbation of cardiometabolic disease. While dietary protein intake and habitual resistance exercise are traditional strategies to offset age-related decrements in lean mass, it is important to define the role of other regulatory nutrients in this process. Dietary vitamin D (VD) has received particular interest as muscle vitamin D receptor (VDR) is associated with hypertrophy. Importantly, beyond being a significant source of high-quality protein, animal-based protein foods are also rich in VD. While previous efforts have investigated the provision of protein and/or VD supplements during a resistance training program, the influence of dietary protein composition and diet-derived VD on resistance exercise adaptations remains unknown. Methods Forty-one middle-aged adults (mean ± SD: age 50 ± 8 y, BMI 27 ± 4 kg/m2, M = 19, F = 22) were stratified and randomized to consume either high (1.68 ± 0.26 g/kg/d) or moderate (1.16 ± 0.19 g/kg/d) amounts of animal-based protein during a 10-week dietary counseling-controlled resistance training program. Dietary intake was monitored by biweekly 3d diet records (ASA24). Dual-energy x-ray absorptiometry and muscle biopsies were performed pre- and post-intervention. Total RNA was extracted and reverse-transcribed for muscle gene expression by quantitative polymerase chain reaction. Intervention outcomes and their relationships were analyzed using linear mixed effects models and repeated measures correlation, respectively, by R. Results VDR gene expression increased regardless of condition (P = 0.007; 95% CI: 0.13, 0.84). Upregulation of VDR expression was correlated with gains in appendicular lean mass (r = 0.44; P = 0.011; CI: 0.10, 0.68). While protein intake did not affect VDR expression, animal-based protein diet density (servings/1000 kcal) was modestly correlated with VDR expression (r = 0.42; P = 0.014; CI: 0.08, 0.67). There was no relationship between dietary VD and VDR expression. Conclusions Our results suggests that moderate dietary protein intake is sufficient to support resistance exercise-induced VDR upregulation and lean mass gain in middle-aged adults. Funding Sources Funded in part by the Beef Checkoff. CFM funded by JBT Fellowship, UIUC.

The association between atopic dermatitis and serum 25-hydroxyvitamin D in children: Influence of sun exposure, diet, and atopy features-A cross-sectional study.

Previous studies have linked low serum vitamin D (VD) or 25-hydroxyvitamin D (25(OH)D) levels with increased severity of atopic dermatitis (AD) in children. To investigate the association between serum VD (25(OH)D) levels and AD and AD severity, considering the influence of diet and sun exposure. We performed a prospective cross-sectional study of healthy controls and children diagnosed with AD. Participants were recruited between January 2011 and December 2012, and the following parameters were assessed: age, sex, body mass index (BMI), AD severity, Fitzpatrick skin type, asthma and rhinitis history, dietary VD intake, daily potential sun-induced VD production, sunscreen use, 25(OH)D and IgE serum levels, and results of the ImmunoCAP Phadiatop Infant test. The study population consisted of 105 healthy controls and 134 AD patients. Serum 25(OH)D levels were significantly lower in moderate and severe AD than in mild AD, although this association was only significant for patients with light Fitzpatrick skin type (mean(SD) 36.7 (11.9) ng/mL; moderate 28.8 [11.5] ng/mL; and severe 27.6 [12.1] ng/mL, P=.045). Logistic regression analysis revealed a positive association between severe AD and both positive ImmunoCAP Phadiatop test and BMI. Our data support an association between VD deficiency and AD severity only in patients with light complexion.

Dietary vitamin D interacts with high phosphate-induced cardiac remodeling in rats with normal renal function.

Vitamin D (VD) and phosphate (Pi) load are considered as contributors to cardiovascular disease in chronic kidney disease and the general population, but interactive effects of VD and Pi intake on the heart are not clearly illustrated. We fed normal male rats with three levels of dietary VD (100, 1100 or 5000 IU/kg chow) and Pi (0.2, 0.6 or 1.6%) (3X3 design) for 8 weeks and examined renal and cardiac function and histology. High dietary Pi decreased plasma and renal Klotho and plasma 25-hydroxyvitamin D, and increased plasma Pi, fibroblast growth factor 23 and parathyroid hormone without affecting renal function, while low Pi increased plasma and renal Klotho. Both low and high VD diets enhanced high Pi-reduced Klotho expression. Low dietary VD reduced-plasma Klotho was rescued by a low Pi diet. High dietary Pi reduced-cardiac ejection fraction was not modified by a low or high VD diet, but the dietary VD effects on cardiac pathologic changes were more complex. High dietary Pi-induced cardiac hypertrophy was attenuated by a low VD and exacerbated by a high VD diet. In contrast, high dietary Pi -induced cardiac fibrosis was magnified by a low VD and attenuated by a high VD diet. High Pi diet induces hypertrophy and fibrosis in left ventricles, a low VD diet accelerates high Pi-induced fibrosis, and a high VD diet exacerbated high Pi -induced hypertrophy. Therefore, cardiac phosphotoxicity is exacerbated by either high or low dietary VD in rats with normal kidney function.

Maternal Diets Deficient in Vitamin D Increase the Risk of Kyphosis in Offspring

The purpose of this study was to explore the role of perinatal vitamin-D intake on the development and characterization of hyperkyphosis in a porcine model. The spines of 16 pigs were assessed at 9, 13, and 17 weeks of age with radiography and at 17 weeks with computed tomography (CT), magnetic resonance imaging (MRI), histology, and bone-density testing. An additional 169 pigs exposed to 1 of 3 maternal dietary vitamin-D levels from conception through the entire lactation period were fed 1 of 4 nursery diets supplying different levels of vitamin D, calcium, and phosphorus. When the animals were 13 weeks of age, upright lateral spinal radiography was performed with use of a custom porcine lift and sagittal Cobb angles were measured in triplicate to determine the degree of kyphosis in each pig. The experimental animals had significantly greater kyphotic sagittal Cobb angles at all time points when compared with the control animals. These hyperkyphotic deformities demonstrated no significant differences in Hounsfield units, contained a slightly lower ash content (46.7% ± 1.1% compared with 50.9% ± 1.6%; p < 0.001), and demonstrated more physeal irregularities. Linear mixed model analysis of the measured kyphosis demonstrated that maternal diet had a greater effect on sagittal Cobb angle than did nursery diet and that postnatal supplementation did not completely eliminate the risk of hyperkyphosis. Maternal diets deficient in vitamin D increased the development of hyperkyphosis in offspring in this model. This study demonstrates that decreased maternal dietary vitamin-D intake during pregnancy increases the risk of spinal deformity in offspring. In addition, these data show the feasibility of generating a large-animal spinal-deformity model through dietary manipulation alone.

Effects of calcium and vitamin D intake level on lipid metabolism in growing rats

Purpose: Association of low intake of calcium (Ca) and inadequate vitamin D (VD) status with higher prevalence rates of obesity has been reported. This study was conducted in order to investigate the effects of different levels of whey Ca and VD intake on lipid metabolism in growing rats. Methods: A total of 56 five-week-old male Sprague-Dawley rats were divided into seven groups and fed for five weeks. Ca groups were divided into three levels, low, normal, and high (0.25%, 0.5%, 1%). VD subgroups in the low and high Ca groups were divided into three levels, low, normal, and high (10 IU, 1,000 IU, and 5,000 IU). The effects of Ca and VD on each group were evaluated by two way ANOVA. Results: Significantly higher amounts of abdominal fat, visceral fat, and epididymal fat were observed in the Low-Ca groups than in the Normal-Ca and High-Ca groups. Serum leptin levels of Low-Ca groups were higher than those of Normal-Ca and High-Ca groups. The highest serum parathyroid hormone concentration was observed in the low Ca·low VD group. The levels of serum 25(OH)D were significantly increased with increasing dietary VD levels. Significantly higher serum levels of triglycerides, total cholesterol, and HDL-cholesterol were observed in the low Ca groups than in the normal Ca and high Ca groups. Conclusion: These results indicate that low calcium intake increased serum lipid level and body fat amount.

Vitamin-D status in relation to bone health in healthy Saudi women

Vitamin-D Status in Relation to Bone Health in Healthy Saudi Women Background: Few studies exist on the various factors that may contribute to vitamin-D status in relation to bone health among Saudi women. Aims: To determine the factors influencing vitamin-D status in relation to serum 25(OH)D, intact-PTH, bone turnover markers (BTMs), bone mineral density (BMD) and vitamin-D receptor genotype (VDR) among healthy Saudi pre- and postmenopausal women. Subjects and Methods: A total number of 1172 healthy Saudi women living in the Jeddah area were randomly selected and studied. Anthropometric parameters, socioeconomic status, sun exposure index together with serum levels of 25(OH)D, calcitriol, intact-PTH, Ca, PO4, Mg, creatinine, albumin and biochemical BTMs were measured. BMD was measured by a dual energy X-ray absorptiometry and VDR genotypes were also determined. Results: About 10.5% of all women exhibited severe vitamin-D deficiency (serum 25(OH)D 75 nmol/L). Increased serum intact-PTH ( > 7.0 pmol/L) were evident in 18.5% and 24.6% in pre- and postmenopausal women with serum 25(OH)D < 50 nmol/L. Serum 25(OH)D was lower (P < 0.001) and intact-PTH higher (P < 0.001) in the upper quintiles of BMI and WHR. Multiple linear regression analysis showed that BMI, sun exposure index < 0.63, poor dietary vitamin-D supplementation, high WHR and age were independent positive predictors of serum 25(OH)D values (R2 = 0.26). The frequencies of VDR genotypes were 32% GG, 45.2% AG and 22.8% AA respectively. There was no significant contribution of VDR genotypes to BMD or BTMs. Conclusions: Vitamin-D deficiency is highly prevalent among healthy Saudi pre- and postmenopausal women and largely attributed to obesity, poor exposure to sunlight, poor dietary vitamin-D supplementation and age.

Soy isoflavones increase bone mineral density without altering markers of whole body vitamin D or calcium metabolism in mice

The soy isoflavone genistein enhances the biological activity of the vitamin D (VD) metabolite 1,25 dihydroxyvitamin D (1,25D) in cultured cells by inhibiting CYP24‐mediated degradation of the hormone. We examined if similar effects can be recapitulated in vivo to improve calcium and bone metabolism. Weanling male B6D2F1 mice were fed AIN‐93G diets containing 50 or 400 IU VD with, or without, Novasoy® 400 soy isoflavone concentrate (added to provide 250 mg genistein/kg diet) until 13 weeks of age. Bone mineral density (BMD) was measured by DEXA. Serum VD metabolites were measured by RIA. Gene expression in duodenum and kidney was measured by RT‐PCR. Higher dietary VD intake increased serum 25 hydroxyvitamin D (25D) from levels viewed as adequate (61 ± 6 nM) to optimal (164 ± 10 nM) for human health but this had no impact on either BMD or molecular indices of calcium metabolism. In contrast, isoflavones increased both serum 25D and femur BMD by 15% (p &lt; 0.01). However, neither serum 1,25D nor tissue gene expression (e.g. duodenal calbindin D9K, TRPV6; renal calbindin D9K or D28K, TRPV5) was influenced by isoflavones. Our data show that the beneficial effect of soy isoflavones on bone that we observed is independent of their ability to modulate whole body VD or calcium metabolism and suggest a direct effect of isoflavones on bone formation or turnover. We thank ADM for Novasoy® 400. Funding: Purdue‐UAB Botanicals Center Pilot Grant.Grant Funding Source: Purdue‐UAB Botanicals Center Pilot Grant

Metacarpal Brown Tumor in Secondary Hyperparathyroidism Due to Vitamin-D Deficiency: A Case Report

B rown tumors are locally destructive bone lesions caused by rapid osteoclastic bone resorption due to severe hyperparathyroidism1. For years, brown tumors have been considered to be characteristic of primary hyperparathyroidism. However, brown tumors also have been reported to occur in patients with severe hyperparathyroidism secondary to chronic renal failure2-4, especially those on long-term hemo-dialysis. Hypocalcemia, hyperphosphatemia, and vitamin-D deficiency are the basic characteristics of chronic renal failure associated with secondary hyperparathyroidism. Fig. 1 Photograph of the lesion at presentation. The appearance of brown tumor lesions in a patient with secondary hyperparathyroidism due to malabsorption has been reported5; but, to our knowledge, there are no reported cases of a patient in whom brown tumor developed secondary to osteomalacia due to inadequate sunlight exposure and dietary vitamin-D deficiency. Our patient was informed that data concerning the case would be submitted for publication. A twenty-eight-year-old woman who had been in purdah (no skin exposed in public except the hands and face) since she was thirteen years old presented with a 4 × 3-cm painful mass in the region of the fourth metacarpal of the right hand without redness or warmth (Fig. 1). Her hand movement was extremely restricted. Radiographs revealed an expansile lytic lesion …