NOTE: When the CV is larger than 60 to 70 percent the distribution of daily intakes is nonnormal and the methods presented here are unreliable.
a Square root of the residual variance after accounting for subject, and sequence of observation (gender and age controlled by classifications).
b Nutrient intakes are for food only, data does not include intake from supplements.
SOURCE: Data from Continuing Survey of Food Intakes by Individuals1994–1996.
, the mean of n days of intake for the individual;
SDwithin, the day-to-day standard deviation of the individual's intake for the nutrient;
EAR, the median nutrient requirement; and
SDr, the standard deviation of requirements in the group.
For nutrients that do not have an EAR, this approach cannot be used. (Guidance on how to assess an individual's usual intake by comparing it to the Adequate Intake [AI] is provided later in this appendix.) When an EAR for the nutrient is provided in a DRI report, the standard deviation of requirements is also available in the form of a coefficient of variation of requirement or percentage of the EAR. In most cases, it is assumed to be 10 percent.
The day-to-day standard deviation in intakes is harder to deter-