Remission of symptoms was achieved by 78.1 and 79.4 % of participants treated with placebo and vitamins by week 12 ( P = 0.840 ) , by 76.5 and 85.3 % at week 26 and 75.8 and 85.5 % at week 52 ( effect of intervention over 52 weeks : odds ratio ( OR ) = 2.49 , 95 % CI 1.12-5 .51 ) .