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Vitamin D deficiency has been linked to bone fragility in children and adults, and to an increased risk of chronic diseases. The main sources of vitamin D are the diet and cutaneous synthesis, the latter being the most important one, since foods are relatively poor in vitamin D. The main factors influencing this endogenous production are the seasons, the time of day, latitude and skin phototype. Due to the contribution of sun exposure in maintaining vitamin D levels, it would be expected that this deficiency would be more prevalent in countries at a high latitude; it has been shown, however, that hypovitaminosis D is commonly found in tropical regions such as Brazil. In high latitude regions in which extreme skin phototypes have been compared, the prevalence of vitamin D deficiency is more common in people with originally darker skin who have a natural barrier to the already lower UV irradiation penetrating the skin. In Brazil, particularly in the areas where sun rays are more abundant, the difference in sunlight exposure between subjects showed no significant variation in serum 25-hydroxyvitamin D (25OHD RESUMOA deficiência de vitamina D tem sido associada à fragilidade óssea em crianças e adultos e ao aumento do risco de doenças crônicas. As principais fontes de vitamina D são a dieta e a síntese cutânea, sendo esta última a mais importante, uma vez que os alimentos são relativamente pobres em vitamina D. Os principais fatores que influenciam essa produção endógena são as estações do ano, a hora do dia, a latitude e o fototipo de pele. Devido à contribuição da exposição solar em manter os níveis de vitamina D, seria de esperar que essa deficiência fosse mais prevalente nos países com alta latitude; no entanto, a hipovitaminose D é comumente encontrada em regiões tropicais como o Brasil. Em regiões de alta latitude em que os extremos de fototipos de pele foram comparados à prevalência de deficiência de vitamina D, é mais comum em pessoas com pele originalmente mais escura que têm uma barreira natural à já baixa penetração da irradiação UV na pele. No Brasil, particularmente nas áreas mais ensolaradas, a diferença de exposição solar entre os indivíduos não mostrou variação significativa nos níveis séricos de 25-hidroxivitamina D (25OHD). Arq Bras Endocrinol Metab. 2014;58(5):540-4 Descritores Deficiência de vitamina D; índice solar; fototipo de pele; 25OHD

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BACKGROUNDVitamin D deficiency has been associated with cardiovascular risk factors, including type 2 diabetes mellitus (T2DM). Evidence shows that patients with low serum 25-hydroxyvitamin D (25OHD) concentrations have a higher risk of developing coronary artery disease.OBJECTIVEThe objective of this study was to assess vitamin D as a predictor of the severity in diabetics with acute coronary syndrome (ACS).METHODSA total of 166 patients were diagnosed with ACS. Serum 25OHD concentrations were analyzed, and risk factors for ACS were evaluated.RESULTSPatients diagnosed as having acute myocardial infarction with elevation of the ST segment had a higher rate of 25OHD, <20 ng/mL compared to ≥30 ng/mL (47.8% × 13.4%, P = 0.03). Diabetics with vitamin D deficiency had more multivessel lesions in the coronary angiography than non-diabetics (69% × 31.8%, P = 0.007). After adjustments for confounders, serum 25OHD remained associated with more severe disease.CONCLUSIONVitamin D deficiency is associated with more severe ACS and is a predictor of more extensive coronary lesions in patients with T2DM.

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