Unexpectedly , serum 25 ( OH ) D concentrations 30 ng/mL were significantly associated with higher mortality as compared to the 20-29 .9 ng/mL reference for HIV-infected ( HR : 2.47 ; 95 % CI : 1.13 , 5.44 ; P = 0.02 ) and HIV-exposed ( HR : 4.00 ; 95 % CI : 1.67 , 9.58 ; P < 0.01 ) infants after multivariate adjustment .