Limitations associated with this study include the small
sample size of the validation population (n Z 50). It may
also be objected that the generalisability of the findings is
limited by the fact that the participants are a nonrepresentative
group of healthy employees in a workplace
setting where dietary exposures are relatively stable.
This may have contributed to the relative accuracy of the
dietary recall methods versus the spot urine sample estimates
in this setting. However as there is no accepted
alternative to a 24-h urine collection suitable for use in all
settings, the findings highlight the need, in specific settings
such as the workplace, to compare and calibrate
methods of estimating 24-h sodium excretion against 24-
h collections. The findings also suggest that in some settings,
dietary methods, in addition to providing valuable
information on the sources of dietary sodium, may also
provide estimates of 24-h intake of adequate accuracy at
the group level.