The intervention did not affect SAEs or BMI , but decreased the incidence of low serum phosphate ( RR , 0.73 ; 95 % CI , 0.55-0 .97 ; P = 0.03 ) and increased the incidence of high serum potassium ( RR , 1.60 ; 95 % CI , 1.19-2 .15 ; P = 0.002 ) and phosphate ( RR , 1.23 ; 95 % CI , 1.10-1 .37 ; P < 0.001 ) .