Task 4: Key Concepts About Dietary Supplement Files

Information on use of vitamin, mineral, herbal, and other dietary supplements is collected from all NHANES participants during the household interview

These data are captured in five files, found on the 2003-2004 Dietary Files page.

Dietary Supplement Data Files
Data File File Name Data Contained in the Data File
Supplement Counts DSQ1
  • participant ID number (SEQN number)
  • a variable to indicate whether or not a dietary supplement was taken
  • total number of supplements taken by the participant in the past 30 days
  • whether or not a non-prescription antacid had been taken and how many
Participant's Use of Supplement (separate records for each supplement taken) DSQ2
  • participant ID number (SEQN number)
  • supplement name and ID number
  • whether the supplement container was seen
  • how long the person has been taking this supplement
  • how often supplement taken in the past 30 days
  • how much supplement was taken each time
Dietary Supplement Product Information DSPI
  • supplement name and ID number
  • general information about the supplement from the NCHS database derived from the supplement label
  • source of the label information
  • type of supplement formulation
  • the number of vitamins, minerals, amino acids, botanicals, and other ingredients listed on the supplement label
  • the serving size upon which the amounts in the Supplement or Nutrition Facts box are based
  • form of the serving size (e.g., tablet, softgel, spray, teaspoon, ml)
Dietary Supplement Ingredient Information DSII
  • supplement name and ID number
  • ingredient ID (ingredients that are in each supplement reported by a participant for which the amount of the ingredient is known, including blends)
Dietary Supplement Blend Information DSBI
  • ingredient ID
  • ID numbers and names of proprietary blends that are also listed as ingredients in File 4
  • components of the blend that have no amounts, are included in this file.



The Dietary Files page has links to each of these data files as well as to the documentation and the procedures used to collect the data.


Be aware that File 1 contains one record per person.  File 2 contains a variable number of records per person, from 0 to multiple records, depending on whether and how many supplements the participant consumed.   Files 3, 4, and 5 contain information only about the supplements and their ingredients.  As shown in the following diagram, the files of this hierarchical data structure can be linked by participant ID, supplement ID, or ingredient ID.


Data File Structure and Relationships

diagram showing relationship of data files


close window icon Close Window to return to module page.