FIGURE 3.

Shortest study length required for accurate prediction of state variables, including TBS, and retinol kinetic parameters (A) or only TBS (B) without or with dietary vitamin A intake included as an input during compartmental modeling. Reference values for TBS (in micromoles) are shown above the bars for each subject. Among the 12 theoretical human subjects, C1–C4 are children, Y5–Y8 are younger adults, and O9–O12 are older adults; see Supplemental Table 1 for more details about each subject. DI, dietary intake; TBS, total body stores.