Improvement in Vitamin D Deficiency Following Antiretroviral Regime Change: Results from the MONET Trial

Low levels of vitamin D are reported in HIV-infected individuals. In HIV-negative people, low vitamin D levels have been associated with an increased risk of cardiovascular disease and cancer and with worse survival. The MONET trial recruited 256 European patients with HIV RNA <50 copies/ml at screening, while taking either NNRTI- or PI-based HAART. Patients were switched to DRV/r 800/100 mg once daily, either as monotherapy or with two NRTIs. In all, 221 patients were measured for 25-hydroxyvitamin D at a central laboratory before randomized treatment started and at week 96. Multiple regression was used to correlate vitamin D levels with gender, season, ethnic group, treatment group, and use of antiretrovirals. Overall, 80% of patients were male and 91% were white, with a mean age of 44 years. At screening, 170/221 (77%) patients had vitamin D deficiency (<50 nmol/liter). At the screening visit, lower vitamin D levels were significantly associated with calendar month (p = 0.0067), black ethnicity (p = 0.013), use of efavirenz (p = 0.0062), and use of zidovudine (p = 0.015). Mean vitamin D levels were lowest from January to April (mean = 35.8 nmol/liter) and highest in September (mean = 45.4 nmol/liter). Increases in vitamin D between screening and week 96 were significantly greater for patients who discontinued efavirenz or zidovudine before the MONET trial versus those who stopped other antiretrovirals. At screening, lower vitamin D levels were associated with season, race, and use of efavirenz and/or zidovudine. Switching from efavirenz and/or zidovudine to darunavir/ritonavir during the trial led to increases in vitamin D levels. Routine screening of HIV-positive patients for vitamin D should be considered and the optimal management further defined.