Examine Usual Total Nutrient Intake from Supplements and Diet
The term “dietary intake” in this module will include foods and beverages reported on the 24-hour recalls in addition to supplement intake from the household interview. Researchers are often interested in estimating the distribution of usual intake of dietary components for a population from all sources, including supplements. This module will focus on using the method developed by researchers at NCI and elsewhere (the “NCI method”) for this purpose.
Many of the statistical methods used in this course are advanced, and may require consultation with a statistician. For modules 18-22, it is required that you have the statistical knowledge of mixed effects models, and program knowledge of calling in SAS macros. Since Module 18 provides the background information for Modules 19-22, it is advised that you carefully read Module 18 first before tackling other modules.
Note that the method described in this tutorial is applicable to the NHANES 2003-2006 data; starting in 2007-2008 dietary supplement data also were collected using 24-hour recalls.
Task 1: Estimate Distributions of Total Nutrient Intake
Dietary supplement use can be an important contributor to total nutrient intake in addition to diet. In NHANES, dietary supplement use information is collected during the household interview using the Dietary Supplement Questionnaire. Information about use, frequency, type, and amount taken over the past 30 days is collected for each supplement. From this, the average daily intake of nutrients from dietary supplements may be calculated for an individual.
- Key Concepts about Estimating Distributions of Total Nutrient Intake
- How to Estimate Distributions of Total Nutrient Intake
- Download Sample Code and Datasets