There were U-shaped associations of vitamin D with total cancer risk : compared with the first quintile , HRs were 0.83 [ 95 % confidence interval ( CI ) , 0.66-1 .03 ; P = 0.092 ] , 0.74 ( 95 % CI , 0.59-0 .92 ; P = 0.008 ) , 0.86 ( 95 % CI , 0.69-1 .07 ; P = 0.181 ) , and 0.98 ( 95 % CI , 0.78-1 .21 ; P = 0.823 ) , for the second through fifth quintiles , respectively .