Mean (±SD) daily 24-h potassium (K+) intake and urinary and fecal excretion in blacks and whites. Repeated-measures ANOVA showed that blacks excreted significantly less urinary potassium from day 2 to the end of the study compared with whites while consuming either the low- or high-sodium (Na+) diet (P < 0.05). No significant differences were observed with fecal output. □, urinary output in whites; ▪, urinary output in blacks; Δ, fecal output in whites; ▴, fecal output in blacks; •, diet.