Mean plasma iPTH decreased from baseline ( 140.3 pg/ml ) by 20.9 6.2 % ( SE ) , 32.8 5.7 and 39.3 4.3 % in the 30 , 60 and 90 g dose groups , respectively , and increased 17.2 7.8 % in the pooled placebo group ( p < 0.005 ) .