Vitamin D and Cardiovascular Disease

Vitamin D insufficiency/deficiency has been observed worldwide at all stages of life. It has been characterized as a public health problem, since low concentrations of this vitamin have been linked to the pathogenesis of several chronic diseases. Several studies have suggested that vitamin D is involved in cardiovascular diseases and have provided evidence that it has a role in reducing cardiovascular disease risk. It may be involved in regulation of gene expression through the presence of vitamin D receptors in various cells, regulation of blood pressure (through renin-angiotensin system), and modulation of cell growth and proliferation including vascular smooth muscle cells and cardiomyocytes. Identifying correct mechanisms and relationships between vitamin D and such diseases could be important in relation to patient care and healthcare policies

Aspectos nutricionais na prevenção e no tratamento da osteoporose

Osteoporosis is a global health problem characterized by low bone mass and microarchitectural deterioration of bone tissue with a consequent increase in bone fragility and susceptibility to fracture. Nutrition plays a critical role in reducing the risk of osteoporosis through its effect on all of these fragility factors, especially on the development and maintenance of bone mass. An adequate calcium, vitamin D and protein intake resulted in reduced bone remodeling, better calcium retention, reduced age-related bone loss, and reduced fracture risk. Recent evidence indicates that a healthy dietary pattern including dairy products (mainly fat free), fruit and vegetables and adequate amounts of meat, fish and poultry is positively related to bone health. Furthermore, mineral and vitamin supplementation should be closely monitored by health professionals since it could have adverse effects and be insufficient to ensure optimal protection of bone health.A osteoporose é um problema de saúde global, caracterizada por baixa massa óssea e deterioração da microarquitetura do tecido ósseo, com consequente aumento da fragilidade óssea e suscetibilidade a fraturas. A nutrição desempenha um papel fundamental na redução do risco de osteoporose por seu efeito sobre todos os fatores relacionados à fragilidade óssea, principalmente no desenvolvimento e na manutenção da massa óssea. Uma adequada ingestão de cálcio, vitamina D e proteína leva à redução da remodelação óssea, à maior retenção de cálcio, à redução da perda óssea relacionada à idade e à redução do risco de fraturas. Evidências recentes indicam que uma alimentação saudável, incluindo a ingestão de produtos lácteos (principalmente os desnatados), frutas e verduras, e uma quantidade adequada de carnes, peixes e aves, está relacionada positivamente com a saúde óssea. Além disso, a suplementação de vitaminas e minerais deve ser monitorada de perto, por profissionais de saúde, uma vez que pode ter efeitos adversos e ser insuficiente para assegurar uma eficaz proteção à saúde óssea

There are no association between vitamin D metabolites and blood pressure in adolescents

OBJETIVO: O objetivo deste estudo foi avaliar a associação entre o estado nutricional da vitamina D, a adiposidade e a pressão arterial (PA) em adolescentes. MÉTODOS: Foi realizada avaliação antropométrica, da composição corporal, da ingestão alimentar, de medidas bioquímicas e aferição da PA de 205 adolescentes, com média de idade de 18,2 anos. RESULTADOS: Destes, 12,19% apresentaram PA elevada. O nível sérico médio da 25OHD foi 29,2(0,8) ng/mL, e 62% dos adolescentes apresentaram insuficiência de vitamina D. Não foi encontrada correlação significativa entre a PAS e a PAD com a 25OHD e a 1,25(OH)2D. Houve correlação negativa entre a PAD com os níveis séricos de adiponectina, e tanto a PAS quanto a PAD apresentaram correlação positiva com a circunferência da cintura em ambos os sexos. CONCLUSÃO: Não houve relação entre os níveis séricos de vitamina D e a PA. Porém, a gordura visceral apresenta risco potencial para elevação da PA em adolescentes.OBJETIVES: The purpose of this study was to evaluate the relationships between serum levels of vitamin D and blood pressure (BP) in adolescents. METHODS: The anthropometric measurements, body composition, dietary intake, blood pressure and biochemical measurements was undertaken. RESULTS: Two hundred and five adolescents, 106 boys and 99 girls, mean aged 18.2 years old, participate of the study. Elevated BP was observed in 12.19% of the adolescents. Mean 25OHD concentration was 29.2(0.8) ng/mL. Vitamin D insufficiency was observed in 62% of adolescents. There were no correlation between systolic and diastolic BP with 25OHD and 1,25(OH)2D concentration. An inverse correlation between adiponectin and diastolic BP was observed and positive significant correlation was observed between waist circumference with systolic and diastolic BP in both boys and in girls. In conclusion, no relationships between vitamin D levels and blood pressure were observed. CONCLUSION: However, the intra-abdominal adiposity offers potential risk to BP elevation in adolescents.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 ± 10 years old), whose 4-day dietary records revealed a regular low calcium intake (<=500 mg/day), received an oral calcium load (1 g/day) for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15), diet-dependent hypercalciuric (DDHC, N = 9) or diet-independent hypercalciuric (DIHC, N = 26). On regular diet, mean oxaluria was 30 ± 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 ± 12 vs 26 ± 7 and 27 ± 18 vs 32 ± 15 mg/24 h, respectively, P<0.05) but not in DDHC patients (22 ± 10 vs 23 ± 5 mg/24 h). The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC) tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.Universidade Federal de São Paulo (UNIFESP) Disciplina de NefrologiaUNIFESP, Disciplina de NefrologiaSciEL

Calcium intake and anthropometric indicators in adolescents

OBJECTIVE: This study was undertaken to determine the relationship between calcium intake and anthropometric indicators in adolescents. METHODS: Students (n=507) from two public and one private schools of Ouro Preto, Minas Gerais, were assessed by means of a questionnaire on socioeconomic conditions, sexual maturity, anthropometry, body composition and food intake. RESULTS: The mean calcium intake was 703.7 (396.0) mg/day and the school with the highest socioeconomic level presented the highest mean intake. Only 8% of the adolescents presented an intake above the recommended intake. Body mass index was inversely associated with calcium (r=-0.203, p=0.001) in the school of intermediate socioeconomic level and also in adolescents with dietary calcium intake between 400 and 800 mg/day (r=-0.134, p=0.044). CONCLUSION: These results showed that calcium intake was insufficient among the adolescents of Ouro Preto, indicating the need to stimulate the consumption of calcium-rich foods in this population.OBJETIVO: Este estudo teve como objetivo investigar a relação da ingestão de cálcio com indicadores antropométricos de adolescentes. MÉTODOS: Foram avaliados 507 alunos de duas escolas públicas e uma particular de Ouro Preto, Minas Gerais, por meio de questionário sobre condições socioeconômicas, avaliação da maturação sexual, antropometria, composição corporal e consumo alimentar. RESULTADOS: A ingestão média de cálcio foi 703,7 (396,0) mg/dia, sendo a maior ingestão verificada na escola de maior nível socioeconômico. Apenas 8% dos adolescentes apresentavam ingestão superior à ingestão adequada. Houve associação negativa do cálcio, ajustado para o índice de massa corporal (r=-0,203, p=0,001), na escola de médio nível socioeconômico e nos adolescentes com ingestão desse mineral entre 400 e 800mg/dia (r=-0,134, p=0,044). CONCLUSÃO: Verificou-se ingestão insuficiente de cálcio entre os adolescentes de Ouro Preto, evidenciando a necessidade de estimular o consumo de alimentos fontes desse mineral nesta população.Universidade de São Paulo Faculdade de Saúde Pública Departamento de NutriçãoUniversidade Federal de Ouro Preto Escola de Nutrição Departamento de Nutrição Clínica e SocialUniversidade Federal de São Paulo (UNIFESP) Centro de Atendimento e Apoio ao Adolescente Departamento de PediatriaUNIFESP, Centro de Atendimento e Apoio ao Adolescente Depto. de PediatriaSciEL

Associação entre osteoporose e artrite reumatóide em mulheres: estudo transversal

CONTEXT AND OBJECTIVES: Osteoporosis has frequently been observed in patients with rheumatoid arthritis. The present study was undertaken in order to evaluate factors associated with osteoporosis among women with rheumatoid arthritis. DESIGN AND SETTING: Cross-sectional study, carried out in a public hospital in São Paulo. METHODS: The participants were 83 women with rheumatoid arthritis (53.7 ± 10.0 years old). Bone mineral density (BMD) and body composition were measured by dual energy X-ray absorptiometry. The patients were divided into three groups according to BMD: group 1, normal BMD (n = 24); group 2, osteopenia (n = 38); and group 3, osteoporosis (n = 21). Tests were performed to compare differences in means and correlations, with adjustments for age, duration of disease and cumulative corticosteroid. The relationships between clinical factors, physical activity score, dietary intake, body composition and biochemical parameters were analyzed using linear regression models. RESULTS: Mean calcium, vitamin D and omega-6 intakes were lower than the recommendations. Associations were found between BMD and age, disease duration, parathyroid hormone concentration and fat intake. The linear regression model showed that being older, with more years of disease and lower weight were negatively correlated with BMD [Total femur = 0.552 + 0.06 (weight) + 0.019 (total physical activity) - 0.05 (age) - 0.003 (disease duration); R² = 48.1; P < 0.001]. CONCLUSION: The present study indicates that nutritional factors and body composition are associated with bone mass in women with rheumatoid arthritis.CONTEXTO E OBJETIVO: A osteoporose é frequentemente observada em pacientes com artrite reumatoide (AR). O presente estudo foi realizado com o objetivo de avaliar fatores associados a osteoporose em mulheres com AR. TIPO DE ESTUDO E LOCAL: Estudo transversal realizado em um hospital público em São Paulo. MÉTODOS: Participaram 83 mulheres com AR (53.7 ± 10.0 anos). A densidade mineral óssea (DMO) e composição corporal foram mensuradas pelo método de densitômetro de dupla emissão com fonte de raios-X. Houve a divisão em grupos conforme a DMO: grupo 1 DMO normal (n = 24); grupo 2 osteopenia (n = 38) e grupo 3 osteoporose (n = 21). Foram realizados testes para comparar diferenças de médias e correlações ajustadas para idade, duração da doença e corticosteroide acumulado. A relação entre fatores clínicos, escore de atividade física, consumo alimentar, composição corporal e parâmetros bioquímicos foram analisados pelo modelo de regressão linear. RESULTADOS: A média de consumo de cálcio, vitamina D e ômega-6 esteve abaixo do recomendado. Houve associação entre DMO e idade, duração da doença, hormônio da paratireóide (PTH) e consumo de gordura. O modelo de regressão linear evidenciou que ser mais velho, apresentar mais anos de doença e menor peso correlacionam-se negativamente com a DMO. [Fêmur total = 0.552 + 0.06 (peso) + 0.019 (atividade física total) - 0.05 (idade) - 0.003 (duração da doença), R² = 48.1; P < 0.001]. CONCLUSÃO: O presente estudo indica que fatores nutricionais e de composição corporal estão associados com a massa óssea em mulheres com AR.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Fatores modificáveis do status de vitamina D em uma população brasileira de osteoporóticos assistidos em um ambulatório público

ObjectiveTo evaluate the serum 25-hydroxyvitamin D [25(OH)D] concentration in Brazilian osteoporotic patients and the modifiable factors of vitamin D status in this population. Subjects and methodIn a cross-sectional study, 363 community-dwelling patients who sought specialized medical care were evaluated between autumn and spring in São Paulo, Brazil. Serum levels of 25(OH)D and parathormone (PTH), biochemical and anthropometric measurements, and bone density scans were obtained. The group was assessed using two questionnaires: one questionnaire covered lifestyle and dietary habits, skin phototype, sun exposure, medical conditions, and levels of vitamin D supplementation (cholecalciferol); the other questionnaire assessed health-related quality-of-life. Logistic regression and a decision tree were used to assess the association between the variables and the adequacy of vitamin D status. Results The mean age of the overall sample was 67.9 ± 8.6 years, and the mean 25(OH)D concentration was 24.8 ng/mL. The prevalence of inadequate vitamin D status was high (73.3%), although 81.5% of the subjects were receiving cholecalciferol (mean dose of 8,169 IU/week). 25(OH)D was positively correlated with femoral neck bone mineral density and negatively correlated with PTH. In the multivariate analysis, the dose of cholecalciferol, engagement in physical activity and the month of the year (September) were associated with improvement in vitamin D status. ConclusionIn this osteoporotic population, vitamin D supplementation of 7,000 IU/week is not enough to reach the desired 25(OH)D concentration (≥ 30 ng/mL). Engagement in physical activity and the month of the year are modifiable factors of the vitamin D status in this population.Objetivos Avaliar a concentração sérica de 25-hidroxivitamina D [25(OH)D] em pacientes osteoporóticos brasileiros e os fatores modificáveis do status de vitamina D nesta população. Sujeitos e métodoEm um estudo transversal, 363 pacientes, residentes na comunidade, que procuravam atendimento médico especializado, foram avaliados entre o outono e a primavera, em São Paulo, Brasil. Níveis séricos de 25(OH)D e paratormônio (PTH), avaliações bioquímicas e antropométricas e exames de densitometria óssea foram obtidos. O grupo foi avaliado por meio de dois questionários: um questionário abordou estilo de vida e hábitos alimentares, fototipo de pele, exposição solar, problemas médicos e os níveis de suplementação de vitamina D (colecalciferol); o outro questionário avaliou a qualidade de vida relacionada à saúde. Regressão logística e árvore de decisão foram utilizadas para avaliar a associação entre as variáveis e a adequação do status de vitamina D. Resultados A idade média da amostra foi de 67,9 ± 8,6 anos e a concentração média de 25(OH)D foi de 24,8 ng/mL. A prevalência de um status de vitamina D inadequado foi elevada (73,3%), apesar de 81,5% dos indivíduos receberem colecalciferol (dose média de 8.169 UI/semana). 25(OH)D correlacionou-se positivamente com a densidade mineral óssea do colo de fêmur e negativamente com PTH. Nas análises multivariadas, a dose de colecalciferol, a prática de exercícios físicos e o mês do ano (setembro) foram associados com a melhora do status de vitamina D. Conclusões Nesta população osteoporótica, a suplementação de 7.000 UI/semana não é suficiente para atingir a concentração desejada de 25(OH)D (≥ 30 ng/mL). A prática de exercícios físicos e o mês do ano são fatores modificáveis do status de vitamina D na população estudada.Federal University of São Paulo School of Medicine Division of EndocrinologyUniversity of São Paulo Faculty of Public Health Department of NutritionUNIFESP, EPM, Division of EndocrinologySciEL

Associations among osteocalcin, leptin and metabolic health in children ages 9-13 years in the United States

BACKGROUND: This study aimed to investigate the relationships among osteocalcin, leptin and metabolic health outcomes in children ages 9-13 years. METHODS: This was a cross-sectional analysis of baseline data from 161 boys and 157 girls (ages 9-13 years) who previously participated in a double-blinded randomized placebo controlled trial of vitamin D supplementation. Relationships among fasting serum total osteocalcin (tOC), undercarboxylated osteocalcin (ucOC), leptin, and metabolic health outcomes were analyzed. RESULTS: Approximately 52% of study participants were obese based on percent body fat cutoffs (>25% for boys and >32% for girls) and about 5% had fasting serum glucose within the prediabetic range (i.e. 100 to 125 mg/dL). Serum tOC was not correlated with leptin, glucose, insulin, HOMA-IR, or HOMA-β after adjusting for percent body fat. However, serum ucOC negatively correlated with leptin (partial r = -0.16; p = 0.04) and glucose (partial r = -0.16; p = 0.04) after adjustment for percent body fat. Leptin was a positive predictor of insulin, glucose, HOMA-IR, and HOMA-β after adjusting for age, sex and percent body fat (all p < 0.001). CONCLUSIONS: These data depict an inverse relationship between leptin and various metabolic health outcomes in children. However, the notion that tOC or ucOC link fat with energy metabolism in healthy children was not supported

Focus on Vitamin D, Inflammation and Type 2 Diabetes

The initial observations linking vitamin D to type 2 diabetes in humans came from studies showing that both healthy and diabetic subjects had a seasonal variation of glycemic control. Currently, there is evidence supporting that vitamin D status is important to regulate some pathways related to type 2 diabetes development. Since the activation of inflammatory pathways interferes with normal metabolism and disrupts proper insulin signaling, it is hypothesized that vitamin D could influence glucose homeostasis by modulating inflammatory response. Human studies investigating the impact of vitamin D supplementation on inflammatory biomarkers of subjects with or at high risk of developing type 2 diabetes are scarce and have generated conflicting results. Based on available clinical and epidemiological data, the positive effects of vitamin D seem to be primarily related to its action on insulin secretion and sensitivity and secondary to its action on inflammation. Future studies specifically designed to investigate the role of vitamin D on type 2 diabetes using inflammation as the main outcome are urgently needed in order to provide a more robust link between vitamin D, inflammation and type 2 diabetes