Estimations of dietary and urinary sodium for the FCW
and validation sample population are presented in Table 2.
In the FCW population, mean estimated sodium intake was
higher in males than in females for all methods. The mean
measured 24-h urinary sodium in the validation was
138 mmol/day (8.1 g), virtually identical to that estimated
from the 24-h dietary recall (134 mmol/day), the arithmetic
extrapolations from morning spot urine samples
(136 mmol/day) and the INTERSALT formula from evening
spot samples (132 mmol/day). Group mean estimates from
morning spot samples were closer than evening samples
to the 24-h estimates of urinary sodium. However for
some methods, notably the Kawasaki method both
morning and evening samples overestimated sodium
excretion relative to the measured 24-h urinary sodium.