Background: We examined the association between vitamin D [25(OH)D] level and disease progression in HIV infection.
Methods: Within the EuroSIDA study, 2000 persons were randomly selected for 25(OH)D measurement in stored plasma samples closest to study entry. 25(OH)D results were stratified into tertiles. Factors associated with 25(OH)D levels and associations of 25(OH) levels with subsequent risk of all-cause mortality, AIDS and non-AIDS events were analyzed.
Results: Of 1985 persons with 25(OH)D levels available, 23.7% had 25(OH)D below 10, 65.3% between 10 and 30, and 11% above 30 ng/ml. At the time of 25(OH)D measurement, older persons, persons of black ethnic origin, living outside Southern Europe/Argentina, sampled during winter, and infected with HIV through nonhomosexual exposure were at higher odds of having low 25(OH)D levels, whereas persons receiving protease inhibitors were at lower odds. Compared to those in the lowest 25(OH)D tertile (<12 ng/ml), those in the middle (12-20) and higher (>20) tertiles had a significantly lower risk of clinical progression during subsequent follow-up. Adjusted incidence rate ratios for all-cause mortality were 0.68 (95% CI 0.47-0.99, P = 0.045) and 0.56 (95% CI 0.37-0.83, P = 0.0039), and for AIDS events were 0.58 (95% CI 0.39-0.87, P = 0.0086) and 0.61 (95% CI 0.40-0.93, P = 0.020), for the middle and higher tertiles, respectively. There was a similar, nonsignificant reduced incidence of non-AIDS events in the middle and higher tertiles.
Conclusion: 25(OH)D deficiency was frequent in HIV-infected persons (83% on combined antiretroviral therapy), and was independently associated with a higher risk of mortality and AIDS events. Causality relationships should be examined, because of potential public health consequences.