Information on human needs for pantothenic acid is limited and no recommended daily allowance has been established, although a safe and adequate level of 4-7 mg/day has been suggested for adults and adolescents. Pantothenic acid levels in urine, whole blood, and erythrocytes were determined by radioimmunoassay in 63 healthy adolescents. Dietary intakes were calculated and evaluated from 4-day diet records. Although 49% of the females and 15% of the males consumed less than 4 mg/day, average blood levels for both groups were in a normal range relative to other populations (411.9 +/- 102.8 ng/mL and 344.5 +/- 113.6 ng/mL, respectively). Dietary intake was highly correlated with urinary excretion (p less than 0.001). Levels of pantothenic acid in erythrocytes correlated well with dietary intake and urinary excretion. A model was developed to predict circulating levels of pantothenic acid from dietary intake and urinary excretion.