The role of single nucleotide variant rs3819817 of the Histidine Ammonia-Lyase gene and 25-Hydroxyvitamin D on bone mineral density, adiposity markers, and skin pigmentation, in Mexican population.

PURPOSE: Vitamin D (VD) deficiency and osteoporosis have become a global public health problem. A variant in the Histidine Ammonia-Lyase (HAL) gene has been associated with VD levels and bone mineral density (BMD). However, whether this variant has an influence on VD levels and BMD in Mexican adults remain unclear. METHODS: This cross-sectional analysis included 1,905 adults participating in the Health Worker Cohort Study and 164 indigenous postmenopausal women from the Metabolic Analysis in an Indigenous Sample (MAIS) cohort. The rs3819817 variant was genotyped by TaqMan probe assay. Total 25 hydroxyvitamin D levels were measured by DiaSorin Liaison. BMD at the different sites was assessed through dual-energy X-ray absorptiometry. Linear and logistic regression models were performed to evaluate the associations of interest. RESULTS: The prevalence of VD deficiency was 41%, showing differences between sexes. Obesity and skin pigmentation were associated with lower levels of VD in males and females. rs3819817-T allele was associated with low levels of 25-hydroxyvitamin D, VD deficiency, and hip and femoral neck BMD values (g/cm2). We found two interactions with VD levels, one between adiposity and rs3819817-T allele (P = 0.017) and another between skin pigmentation and rs3819817-T allele (P = 0.019). In indigenous postmenopausal women, we observed higher VD levels in the southern region compared to the northern region (P < 0.001); however, we did not observe differences by genotype. CONCLUSION: Our findings confirm that the genetic variant rs3819817 has an essential function in VD levels and BMD and suggests a role in skin pigmentation in the Mexican population.

Associations of vitamin D deficiency with MRI markers of brain health in a community sample.

BACKGROUND & AIM: Vitamin D deficiency has been linked to an increased risk of dementia. To strengthen this evidence and establish whether vitamin D can indeed play a role in early prevention of neurodegeneration, knowledge on underlying pathways is crucial. Therefore, we aimed to investigate the association of vitamin D status with brain tissue volumes, hippocampus volume, white matter integrity, and markers of cerebral small vessel disease (CSVD) in a dementia-free population. METHODS: In this cross-sectional analysis, 2,716 participants free of dementia from the population-based Rotterdam Study underwent serum 25(OH)D concentration assessment and brain magnetic resonance imaging (MRI) scanning between 2006 and 2009. Outcomes of interest included brain tissue volume (total, white matter, grey matter and hippocampus volume), white matter integrity (fractional anisotropy (FA) and mean diffusivity (MD)), and markers of CSVD (white matter hyper intensity (WMH) volume, presence of lacunes and microbleeds). Associations between vitamin D status, both in categories and continuous, and these brain measurements were assessed using multivariable linear and logistic regression models, adjusting for lifestyle and other disease risk factors. RESULTS: We observed that vitamin D deficiency (25(OH)D < 30 nmol/L) was independently associated with smaller brain tissue volume, smaller white matter volume and smaller hippocampus volume as compared to a sufficient vitamin D status (≥50 nmol/L). Vitamin D per 10 nmol/L increment and an insufficient (30-50 nmol/L) as compared to sufficient vitamin D status were not associated with the brain measures of interest. Moreover, vitamin D status was not associated with grey matter volume, white matter integrity or CSVD markers. CONCLUSIONS: In this dementia-free population, vitamin D deficiency was associated with a smaller brain tissue volume and hippocampus volume. More research, in particular with a longitudinal design, is needed to further elucidate the role of vitamin D in neurodegeneration.

Are there any seasonal variations in 25-hydroxyvitamin D and parathyroid hormone serum levels in children and adolescents with severe obesity?

The objective of this study was to analyze the prevalence of hypovitaminosis D in children with severe obesity. We hypothesized that severe obesity could modify the seasonal variations in 25(OH)D and PTH serum levels throughout the year. A cross-sectional clinical and blood testing (calcium, phosphorus, 25(OH)D, and PTH) was carried out in 282 patients with severe obesity, aged 7.2-15.2 years. A control group was recruited (348 healthy children, aged 7.1-14.9 years). The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D. Vitamin D deficiency and hyperparathyroidism were more frequent (p < 0.05) in the obesity group (44.5 vs. 11.5% and 22.4 vs. 3.9%, respectively). There were seasonal variations in 25(OH)D levels in the obesity group, but they were lower (p < 0.05) with respect to the control group. In contrast, PTH levels were higher (p < 0.05) in the obesity group with respect to the control group, but there were no significant seasonal variations in PTH levels.Conclusion: Suboptimal vitamin D status and high levels of PTH are a common feature in pediatric population with severe obesity. In these patients, the seasonal variations in 25(OH)D were not modified, and PTH levels remained increased throughout the year, but without any seasonal variations. What is Known: • Obesity has been associated with lower 25(OH)D and higher PTH levels. • Relation among vitamin D and PTH through a natural year in children with obesity is partially known. What is New: • Seasonal variations in 25(OH)D are maintained in children with severe obesity, but PTH levels remained increased throughout the year, without seasonal variations. • -PTH levels in obesity are independent of vitamin D status and do not appear to represent secondary hyperparathyroidism.

Vitamin D status and prevalence of hypovitaminosis D in different genders throughout life stages: A Brazilian cross-sectional study

OBJECTIVES: To evaluate the mean concentration of 25-hydroxivitamin D [25(OH) D] and prevalence of hypovitaminosis D in individuals residing in Rio de Janeiro, Brazil. METHODS: The data of 80,000 consecutive individuals who had 25(OH) D measurements performed by electrochemiluminescence between 1/2/2018 and 2/5/2018 were selected. Patients who reported the use of therapies/supplements were excluded. Levels of 25(OH) D ≥20 ng/mL (ages <60 years) and ≥30 ng/mL (ages ≥60 years) were considered adequate. RESULTS: We analyzed the data of 24,074 individuals (1-95 years old, 64.7% female). Descriptive curves showed that, in both sexes, the mean values of 25(OH) D decreased from the first years of life until adolescence, then slightly increased, and then tended to stabilize during adulthood. Levels of 25(OH) D <20 ng/mL were observed in 6% of girls versus 3.6% of boys and in 13.6% of adolescent girls versus 12.6% of adolescent boys and 11% of adults. The percentage of seniors with serum levels of 25(OH) D <20 ng/mL was 13.6% in women and 12.7% in men; 53.2% of women and 50.6% of men had levels <30 ng/mL. CONCLUSIONS: Mean 25(OH) D values were higher in children and lower in adolescents and women. Approximately 90% of non-seniors and presumably healthy residents of the urban metropolitan region of Rio de Janeiro presented satisfactory levels of 25(OH) D during the summer months; however, in over half of the elderly, the serum concentrations of 25(OH) D were inadequate. Therefore, strategies for the prevention of hypovitaminosis D should be considered in the senior population.

Lower serum 25-hydroxyvitamin D3 concentration is associated with higher pain and disability in subjects with low back pain: a case-control study.

OBJECTIVES: Low back pain (LBP) is a common medical problem worldwide. The aim of this study is to evaluate the association between serum concentration of 25-hydroxivitamin D3 and functional disability in patients suffering from LBP in a sample of Azeri middle-aged subjects, North West of Iran. RESULTS: In this case-control study, 63 eligible patients with LBP and 55 healthy subjects enrolled in the study. Peripheral venous blood was taken for evaluating the serum concentration of 25-hydroxivitamin D3. We recognized factors related with LBP by multiple regression analyses. The average serum 25-hydroxivitamin D3 concentration in case group was significantly lower than that of the matched controlled group (26.25 ± 15.95 vs. 34.20 ± 14.92, p-value < 0.01 respectively). Subjects with vitamin D deficiency or insufficiency were more likely to exhibit LBP than subjects with normal serum 25-hydroxivitamin D3 concentration [(OR = 2.388, 95% CI (1.114 to 5.119)]. According to the partial correlation analysis, there was a reverse correlation between serum 25-hydroxivitamin D3 concentration with functional disability measured by Modified Oswestry Questionnaire (r = - 0.307, p = 0.017) and also with pain intensity according to Visual Analogue Scale (VAS) score (r = - 0.268, p = 0.040) whilst adjusting for age, sex and body mass index (BMI).

The Associations of Vitamin D Status with Athletic Performance and Blood-borne Markers in Adolescent Athletes: A Cross-Sectional Study.

The purpose of this study was to examine the associations of vitamin D status with athletic performance and blood-borne markers in adolescent athletes. This cross-sectional study included forty-seven Taekwondo athletes, aged 15-18 years old. Athletic performance was assessed using maximal oxygen consumption (VO2max), Wingate anaerobic power test, vertical jump, agility T-test, lower limb muscle strength, and fatigue resistance. Blood samples were collected to assess serum 25-hydroxyvitamin D [25(OH)D], free-testosterone, cortisol, creatine kinase, and urea. One-way ANOVAs were applied using Bonferroni adjusted alpha levels, which was 0.02 (i.e., 0.05/3). Multiple linear regressions analyses as well as Pearson and partial correlation analyses were used to examine the relationship among 25(OH)D concentration, athletic performance, and blood-borne markers. The participants 25(OH)D concentration were ranged from 16 to 73.25 nmol/L, indicating that 74.5% of the adolescent athletes have vitamin D insufficiency or deficiency. The vitamin D status did not show any significant effects on the performance factors or blood-borne markers. Serum 25(OH)D concentration was positively correlated with mean power output (r = 0.359, p < 0.05) and relative mean power output (r = 0.325, p < 0.05) after adjusting for bone age, height, weight, training experience, lean body mass, and fat mass. However, 25(OH)D concentration was not associated with other performance-related factors and blood-borne markers. In addition, multiple linear regressions analyses revealed that serum 25(OH)D concentration were not significant predictors of athletic performance in adolescent athletes. In conclusion, vitamin D status is weakly correlated with anaerobic capacity; moreover, the underlying mechanisms of how vitamin D influence anaerobic performance is unclear in the present study. Nevertheless, the importance of vitamin D on health benefits should not be underestimated, especially during growth periods.

Vitamin D and body composition in the elderly.

OBJECTIVE: To investigate the association between vitamin D status and body composition in the elderly. METHODS: This study was embedded in the Rotterdam Study, a population-based prospective study in Rotterdam, the Netherlands, including subjects aged 55 years and older. Serum 25-hydroxyvitamin D (25(OH)D) was measured between 1997 and 1999. Total body fat, android fat, gynoid fat and lean mass were assessed using dual-energy X-ray absorptiometry (DXA) during a follow-up visit after a median time of 5 years (2002-2004). We calculated body fat percentage, lean mass percentage, and android/gynoid fat ratio. We had 2158 participants included in our analysis. We used multivariable linear regression models. Serum 25(OH)D was analyzed continuously and after categorization according to cut-offs. RESULTS: Mean (±SD) serum 25(OH)D concentration of the study population was 52.6 ± 25.4 nmol/L. Compared to subjects with an adequate vitamin D status (25(OH)D ≥ 75 nmol/L), vitamin D deficient participants (25(OH)D < 50 nmol/L) had a higher body fat percentage (ß = 1.29, 95% CI: 0.55, 2.04) whereas no association was found with lean mass (ß = 0.01, 95%CI: -0.33, 0.35). Lower 25(OH)D was associated with higher total body fat percentage specifically in participants without cardio-metabolic disease. Each 10 unit increase in serum 25(OH)D was associated with 0.03 unit decrease in android fat (ß = -0.03, 95%CI: -0.06, -0.01); after adjustment for BMI the association was no longer significant. Serum 25(OH)D was also associated with the android/gynoid fat ratio but this was also mainly explained by BMI. CONCLUSION: Lower serum 25(OH)D concentrations were associated with a higher fat mass percentage. The association between serum 25(OH)D and differential fat distribution in the elderly was mainly explained by BMI and deserves further study.

Vitamin D deficiency at pediatric intensive care admission / Deficiência de vitamina D em internações na unidade de terapia intensiva pediátrica

OBJECTIVE: to assess whether 25hydroxivitaminD or 25(OH)vitD deficiency has a high prevalence at pediatric intensive care unit (PICU) admission, and whether it is associated with increased prediction of mortality risk scores. METHOD: prospective observational study comparing 25(OH)vitD levels measured in 156 patients during the 12 hours after critical care admission with the 25(OH)vitD levels of 289 healthy children. 25(OH)vitD levels were also compared between PICU patients with pediatric risk of mortality III (PRISM III) or pediatric index of mortality 2 (PIM 2) > p75 [(group A; n = 33) vs. the others (group B; n = 123)]. Vitamin D deficiency was defined as < 20 ng/mL levels. RESULTS: median (p25-p75) 25(OH)vitD level was 26.0 ng/mL (19.2-35.8) in PICU patients vs. 30.5 ng/mL (23.2-38.6) in healthy children (p = 0.007). The prevalence of 25(OH)vitD < 20 ng/mL was 29.5% (95% CI: 22.0-37.0) vs. 15.6% (95% CI: 12.2-20.0) (p = 0.01). Pediatric intensive care patients presented an odds ratio (OR) for hypovitaminosis D of 2.26 (CI 95%: 1.41-3.61). 25(OH)vitD levels were 25.4 ng/mL (CI 95%: 15.5-36.0) in group A vs. 26.6 ng/mL (CI 95%: 19.3-35.5) in group B (p = 0.800). CONCLUSIONS: hypovitaminosis D incidence was high in PICU patients. Hypovitaminosis D was not associated with higher prediction of risk mortality scores. .

OBJETIVO: avaliar se a deficiência da 25-hidroxivitamina D, ou 25 (OH) vitD, tem prevalência elevada em internações na unidade de terapia intensiva pediátrica, e se estaria relacionada à previsão de escores de risco de mortalidade. MÉTODO: estudo observacional prospectivo comparando níveis de 25 (OH) vitD de 156 pacientes, mensurados nas primeiras 12 horas da internação em terapia intensiva, com níveis de 25 (OH) vitD de 289 crianças saudáveis. Os níveis de 25 (OH) vitD também foram comparados entre pacientes na UTIP com escore PRISM III ou PIM 2 > p75 (Grupo A; n = 33), e o restante, (Grupo B; n = 123). A deficiência de vitamina D foi definida como níveis < 20 ng/mL. RESULTADOS: o nível médio (p25-p75) de 25 (OH) vitD foi 26,0 ng/mL (19,2-35,8) em pacientes internados na UTIP, em comparação a 30,5 ng/mL (23,2-38,6) em crianças saudáveis (p = 0,007). A prevalência de 25 (OH) vitD < 20 ng/mL foi de 29,5% (IC 95%, 22,0-37,0), em comparação a 15,6% (IC 95%,12,2-20,0) (p = 0,01). Os pacientes em terapia intensiva pediátrica apresentaram uma razão de chance (RC) para hipovitaminose D de 2,26 (IC 95%, 1,41-3,61). Os níveis de 25 (OH) vitD foram 25,4 ng/mL (IC 95%, 15,5-36,0) no grupo A, em comparação a 26,6 ng/mL (IC 95%, 19,3-35,5) no grupo B (p = 0,800). CONCLUSÕES: a incidência de hipovitaminose D foi elevada em pacientes em terapia intensiva pediátrica, mas não foi associada à maior previsão de escores de risco de mortalidade. .

Vitamin D deficiency at pediatric intensive care admission.

OBJECTIVE: to assess whether 25hydroxivitaminD or 25(OH)vitD deficiency has a high prevalence at pediatric intensive care unit (PICU) admission, and whether it is associated with increased prediction of mortality risk scores. METHOD: prospective observational study comparing 25(OH)vitD levels measured in 156 patients during the 12 hours after critical care admission with the 25(OH)vitD levels of 289 healthy children. 25(OH)vitD levels were also compared between PICU patients with pediatric risk of mortality III (PRISM III) or pediatric index of mortality 2 (PIM 2) > p75 [(group A; n = 33) vs. the others (group B; n = 123)]. Vitamin D deficiency was defined as < 20 ng/mL levels. RESULTS: median (p25-p75) 25(OH)vitD level was 26.0 ng/mL (19.2-35.8) in PICU patients vs. 30.5 ng/mL (23.2-38.6) in healthy children (p = 0.007). The prevalence of 25(OH)vitD < 20 ng/mL was 29.5% (95% CI: 22.0-37.0) vs. 15.6% (95% CI: 12.2-20.0) (p = 0.01). Pediatric intensive care patients presented an odds ratio (OR) for hypovitaminosis D of 2.26 (CI 95%: 1.41-3.61). 25(OH)vitD levels were 25.4 ng/mL (CI 95%: 15.5-36.0) in group A vs. 26.6 ng/mL (CI 95%: 19.3-35.5) in group B (p = 0.800). CONCLUSIONS: hypovitaminosis D incidence was high in PICU patients. Hypovitaminosis D was not associated with higher prediction of risk mortality scores.