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g Intake measured as mg/1000 kcal; energy intake not provided.

h Abnormal EGRAC = > 1.2.

i During exercise period.

j Abnormal EGRAC = > 1.25.

k Abnormal EGRAC = ≥ 1.3.

l Abnormal EGRAC = > 1.4.

m Abnormal urinary excretion = values before which there is a sharp increase (breakpoint for increase in slope of urinary excretion).

n Normal = no classical signs of riboflavin deficiency.

o Normal = no signs of ariboflavinosis (assessment based on eye exams, work performance, and psychomotor tests).

p Abnormal = nonspecific symptoms (cheilosis, angular stomatitis, scrotal skin changes).

q Abnormal = severe skin lesions.

r Abnormal total erythrocyte riboflavin = < 400 nmol/L (15 µg/100 mL); authors’ conclusion.

s Normal total erythrocyte riboflavin = ≥ 530 nmol/L (20 µg/100 mL); authors’ conclusion.

t Abnormal = severe symptoms of ariboflavinosis.

latter occurred in only one study on elderly Guatemalans (Boisvert et al., 1993). The value selected for the EAR for riboflavin was the intake that was sufficient to maintain or restore adequate status in half the individuals in the groups studied.

Ancillary: Kinetic, Catabolic, and Clinical Reflections of Riboflavin Status

Whole-body dynamics based on pharmacokinetic analysis were used to set limits for rates and amounts of riboflavin absorption and excretion and appeared to reflect the flux of major metabolites (Zempleni et al., 1996). Such analysis assumes that the upper limits for utilization and storage have been reached if there is a rapid increase in the excretion of vitamin in the urine. The suppression or regression of clinical signs, largely dermatological, provide guide-posts for lowest limits.

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