%0 Journal Article %T Prevalence and Factors Associated with Vitamin D Deficiency and Hyperparathyroidism in HIV-Infected Patients Treated in Barcelona %A Elisabet Lerma %A M. Ema Molas %A M. Milagro Montero %A Ana Guelar %A Alicia Gonz¨¢lez %A Judith Villar %A Adolf Diez %A Hernando Knobel %J ISRN AIDS %D 2012 %R 10.5402/2012/485307 %X Vitamin D deficiency is an important problem in patients with chronic conditions including those with human immunodeficiency virus (HIV) infection. The aim of this cross-sectional study was to identify the prevalence and factors associated with vitamin D deficiency and hyperparathyroidism in HIV patients attended in Barcelona. Cholecalciferol (25OH vitamin D3) and PTH levels were measured. Vitamin D insufficiency was defined as 25(OH) D < 20£¿ng/mL and deficiency as <12£¿ng/mL. Hyperparathyroidism was defined as PTH levels >65£¿pg/mL. Cases with chronic kidney failure, liver disease, treatments or conditions potentially affecting bone metabolism were excluded. Among the 566 patients included, 56.4% were exposed to tenofovir. Vitamin D insufficiency was found in 71.2% and 39.6% of those had deficiency. PTH was measured in 228 subjects, and 86 of them (37.7%) showed high levels. Adjusted predictors of vitamin D deficiency were nonwhite race and psychiatric comorbidity, while lipoatrophy was a protective factor. Independent risk factors of hyperparathyroidism were vitamin D < 12£¿ng/mL (OR: 2.14, CI 95%: 1.19¨C3.82, P: 0.01) and tenofovir exposure (OR: 3.55, CI 95%: 1.62¨C7.7, P: 0.002). High prevalence of vitamin deficiency and hyperparathyroidism was found in an area with high annual solar exposure. 1. Introduction Vitamin D is a steroid liposoluble hormone and can be made available to the individuals in two forms. First, vitamin D3 or cholecalciferol is synthesized in the skin in response to ultraviolet B radiation and is present in oil-rich fish (salmon, mackerel, and herring), egg yolks, and liver [1]. Second, vitamin D2 or ergocalciferol is obtained from the UV irradiation of the yeast sterol ergosterol and is found in sun-exposed mushrooms [2]. Both vitamins undergo identical metabolism, and as they are biologically inert, they require two hydroxylations, in the liver and in the kidney, to become 1,25dihydroxyvitamin D [1,25(OH)2D] which is the biologically active form of the hormone [3, 4]. In the intestine this stimulates the absorption of calcium and phosphorus, and it helps to regulate the metabolism of both minerals within bone and kidney interaction [5]. Assessment of vitamin D is based on measurement of serum 25(OH)D [6, 7] that is the most stable and plentiful metabolite of vitamin D in serum and has a half-life about 21 days [8]. The main source of vitamin D is exposure to sunlight [9, 10]. Therefore, an insufficient exposure to sunlight is a major cause of vitamin D deficiency. Other causes of vitamin deficiency are sunscreen sun protection [2], %U http://www.hindawi.com/journals/isrn.aids/2012/485307/