Seasonal variation of vitamin D among healthy adult men in a subtropical region

SUMMARY OBJECTIVE: To evaluate seasonal variation of 25(OH)vitamin D [25(OH)D3] levels, and factors associated with it, in healthy adult men, who exercised outdoors for 50 min., at least twice a week, from 10AM to 4PM, in a Brazilian semitropical region. METHODS: Blood samples were collected at the end of each season for 25(OH)D3, measured by liquid chromatography with tandem mass spectrometry. Ultraviolet irradiation was estimated by radiometer, calculating the daily photobiological response to vitamin D synthesis in human skin (D-VitD). The prevalence of 25(OH)D3 <20ng/mL changed with the seasons (p=0.000): 8.7% (n=6/69), 1.5% (n=1/66), 0 (n=0/64), and 21.7% (n=13/60), respectively, at the end of winter, spring, summer, and autumn. The prevalence, adjusted for multiple comparisons, was higher in winter than summer (p=0.026), and in autumn than spring (p=0.001) and summer (p=0.000). There were no associations of 25(OH) D3 levels with BMI (p=0.207), body fat (p=0.064), and phototype (p=0.485), in univariate analysis. It was associated with D-VitD in the 30 days before blood sampling (p=0.000), after adjustment to body fat. The prevalence of 25(OH)D3 <30ng/mL varied seasonally (p=0.000): 69.6% (n=48/69), 68.2% (n=45/66), 43.8% (n=28/64), and 88.4% (n=53/60), respectively, in winter, spring, summer, and autumn. CONCLUSIONS: In a Brazilian subtropical region, a seasonal variation in 25(OH)D3 was observed in healthy adult males, although they spent at least 50 min outdoors twice a week, wearing shorts and T-shirts. 25(OH)D3 <20ng/mL was 21.7% in autumn; D-vitD 30 days prior to blood sampling was the only factor independently associated with 25(OH)D3 levels.

RESUMO OBJETIVOS: Avaliar a sazonalidade da 25(OH)vitamina D3 [25(OH)D3] e fatores associados em homens adultos saudáveis, que se exercitavam ao ar livre pelo menos 50 min duas vezes por semana, das 10 às 16h, em uma região subtropical. MÉTODOS: Sangue foi colhido no fim das estações para medir 25(OH)D3, por cromatografia líquida em tandem com espectroscopia de massas. A radiação ultravioleta foi estimada por radiômetro, calculando diariamente a resposta fotobiológica para sintetizar vitamina D na pele humana (D-VitD). RESULTADOS: A prevalência de 25(OH)D3 <20ng/mL foi sazonal (p=0.000): 8.7% (n=6/69), 1.5% (n=1/66), 0% (n= 0/64), e 21.7% (n=13/60), respectivamente, no final do inverno, primavera, verão e outono. A prevalência, ajustada para comparações múltiplas, foi maior no inverno do que no verão (p=0.026) e no outono do que na primavera (p=0.001) e verão (p=0.000). A 25(OH)D3 não se associou com o índice de massa corporal (p=0.207), gordura corporal (p=0.064) ou fototipo (p=0.485), na análise univariada. Associou-se à D-VitD nos 30 dias antes da coleta de sangue (p=0.000), ajustada para gordura corporal. Houve sazonalidade na prevalência de 25(OH)D3 <30ng/mL (p=0.000): 69.6% (n=48/69), 68.2% (n=45/66), 43.8% (n=28/64), e 88.4% (n=53/60), respectivamente, no inverno, primavera, verão e outono. CONCLUSÕES: Em uma região subtropical, houve sazonalidade na 25(OH)D3 em homens adultos, saudáveis, embora se exercitassem ao ar livre pelo menos 50 minutos duas vezes por semana, usando shorts e camiseta. 25(OH)D3 <20ng/mL foi 21.7% no outono e a D-vitD 30 dias antes da coleta do sangue foi o único fator associado de modo independente à 25(OH)D3.

Solar ultraviolet radiation: properties, characteristics and amounts observed in Brazil and South America

Abstract The beneficial and harmful effects of human exposure to solar ultraviolet radiation (UV-R) are topics that arouse great interest not only among physicians and scientists, but also the general public and the media. Currently, discussions on vitamin D synthesis (beneficial effect) are confronted with the high and growing number of new cases of non-melanoma skin cancer and other diseases of the skin and eyes (harmful effect) diagnosed each year in Brazil. However, the lack of scientific knowledge on the UV-R in Brazil and South America leads to adoption of protective measures based on studies conducted in Europe and USA, where the amounts of UV-R available at surface and the sun-exposure habits and characteristics of the population are significantly different from those observed in Brazil. In order to circumvent this problem, the Brazilian Society of Dermatology recently published the Brazilian Consensus of Photoprotection based on recent studies performed locally. The main goal of this article is to provide detailed educational information on the main properties and characteristics of UV-R and UV index in a simple language. It also provides: a) a summary of UV-R measurements recently performed in Brazil; b) a comparison with those performed in Europe; and, c) an evaluation to further clarify the assessment of potential harm and health effects owing to chronic exposures.

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.

Estimativa do custo do tratamento de câncer de pele tipo melanoma no Estado de São Paulo - Brasil / An estimate of the cost of treating mlanoma disease in the state of Sao Paulo - Brazil

FUNDAMENTOS: O impacto econômico do diagnóstico e do tratamento do melanoma cutâneo não tem sido analisado no Brasil. Uma vez que crescem tanto a incidência do câncer de pele quanto a preocupação com ele, é importante que isto seja avaliado. OBJETIVO: O objetivo deste trabalho foi estimar o custo direto de diagnosticar e tratar em seus diversos estádios o melanoma cutâneo em número de casos ocorridos no Estado de São Paulo, entre 2000 e 2007. MÉTODOS: Como modelo de procedimento, foi utilizado o projeto diretriz (Clinical Practice Guidelines in Oncology), editado pelo National Comprehensive Cancer Network (NCCN) e adequado aos procedimentos da Fundação SobecCan - Hospital do Câncer de Ribeirão Preto - SP. Os custos estimados se baseiam nos valores do tratamento médico pagos pelo setor público (Sistema Único de Saúde - SUS) e pelo setor privado (convênios) em 2007. Houve 2.740 casos diagnosticados e estadiados no Estado de São Paulo no período estudado. RESULTADOS: O custo total de tratamento dos melanomas malignos diagnosticados no estádio inicial, em valores de 2007, foi estimado em R$ 33.012.725,10 para o SUS e R$ 76.133.662,80 para os convênios.Os estádios iniciais 0, I e II da doença compreendem aproximadamente 4,2 por cento (SUS) e 1, 3 por cento (convênios) do custo total; os estádios III e IV consomem 95,8 por cento e 98,7 por cento do custo total, respectivamente. CONCLUSÃO: Os resultados apresentados reforçam o argumento de que o diagnóstico do melanoma cutâneo em seus estádios iniciais reduz os custos de tratamento, gerando considerável economia tanto para o sistema público de saúde (SUS) quanto para o sistema privado (convênios).

OBJECTIVE: The purpose of this study was to estimate the direct cost of diagnosing and treating melanoma disease in Sao Paulo (Brazil) between the years 2000 and 2007. METHODS: The project Clinical Practice Guidelines in Oncology was used, adapted to the proceedings of SOBECCan Foundation. The estimated costs were based on the values of the medical treatment paid by the Brazilian National Health System (SUS) and private healthcare insurance companies (PHIC) in 2007. RESULTS: The total cost was estimated in R$33,012,725.1 (SUS) and R$76,133,662.8 (PHIC). Stages 0, I and II comprised about 4.2 percent (SUS) and 1.3 percent (PHIC) of the total cost; stages III and IV amounted to 95.8 percent and 98.7 percent of the total cost, respectively. CONCLUSION: The diagnosis of malignant melanoma in its initial stages reduces treatment costs generating considerable savings of resources for both National Health System and private healthcare insurance companies.