less than 4 mg/day supported normal concentrations of pantothenic acid (1.57 to 2.66 µmol/L) (Wittwer et al., 1989) in whole blood.

Similarly, Kathman and Kies (1984) reported that during a 4-day test period, eight boys and four girls aged 11 to 16 years had average pantothenic acid intakes of 5.6 mg/day (range 4.0 to 7.9 mg/ day). These values were calculated from diet diaries and check lists. Average urinary pantothenic acid excretion was 3.74 mg/g of creatinine. However, over this 4-day period there was no statistically significant correlation between pantothenic acid intake and excretion.

By extrapolating the AI for adolescents from the adult AI for pantothenic acid using the method described in Chapter 2, a value of 5 mg/day is obtained when urinary excretion was converted to mg/ day from mg/g creatinine, which is consistent with the results reviewed above.

The usual pantothenic acid intake is 4 to 7 mg/day, as reported for small groups of U.S. adults and adolescents (Bull and Buss, 1982; Kathman and Kies, 1984; Srinivasan et al., 1981; Tarr et al., 1981). There is no evidence suggesting that this range of intake is inadequate. Thus, the approximate midpoint—5 mg/day—is set as the AI for adults. The adequacy of this intake is supported by the only study of the relationship between daily intake and excretion in adults (Fox and Linkswiler, 1961). Eight healthy women aged 18 to 24 years were studied to determine the urinary excretion of pantothenic acid on three levels of intake in the normal range. On self-selected diets the women consumed 3.4 to 10.3 mg/day of pantothenic acid as estimated from the tables of Zook et al. (1956) and Sarrett et al. (1946). Diets were then standardized to include 2.8 mg/day of pantothenic acid for 15 days, 7.8 mg/day for 10 days, and 12.8 mg/day for 10 days. The mean urinary excretion of pantothenic acid after consumption of these pantothenic acid intakes