As displayed in Table 3, among HIV-positive subjects, factors associated with higher FGF23 levels at baseline included being female (adjusted ratio of geometric means; 95% confidence interval [CI]), 1.46;1.21, 1.76), serum phosphorus (1.21 per mg/dL higher; 1.03, 1.42), and HCV coinfection (1.31;1.10, 1.56). Here, FGF23 is linked to coinfection.