VITYVITAUN is a variable with five columns and no implied decimal place.
For sample adults in 1987 who had taken vitamin or mineral supplements (VITANY) and vitamin A (VITAMINA) in the past 12 months, VITYVITAUN reports the number of international units of vitamin A in each pill taken by the respondent (VITYVITAPILS).
Although the wording of the survey question associated with VITYVITAUN refers only to "units," the 1987 Field Representative's Manual suggests that "units" is intended to mean "international units" (IU).
The Manual offers these instructions to interviewers:
Question 3e asks for the number of units of Vitamin A in each pill. If the bottle says to take 2 pills to get 1,000 IU, enter 500 since that is the number of IUs in each pill.
International units are defined by the Office of Dietary Supplements at the National Institutes of Health as "a measurement used to measure the activity of some vitamins and other biological substances (such as enzymes and hormones)." (http://ods.od.nih.gov/factsheets/showterm.aspx?tID=296)
It is possible to use both VITYVITAUN and VITYVITAPILS to determine the number of IU of vitamin A respondents were taking, on days they took vitamin A. The related variables VITAMINAMO and VITAMINADMO report the frequency of respondents' use of vitamin A in number of months and number of days per month, respectively.
Analysts interested in the units of vitamin A taken may wish to consult the following variables, which report similar information for other vitamins/minerals (all only available for 1987). Users should note that vitamin E is also measured in international units (a measure of biological activity), but vitamin C and calcium are measured in milligrams (a measure of quantity). Further, a direct comparison of IU across substances is not possible. That is, 1,000 IU of vitamin A is not equivalent to 1,000 IU of vitamin E.
- VITYVITCMG Vitamin C
- VITYVITEUN Vitamin E
- VITYCALCMG Calcium
For more information on the full range of variables related to vitamins and minerals, see VITANY.
- 1987: Half of sample persons age 18+ (excluded from CACT supplement) who took vitamin/mineral supplements and vitamin A in the past 12 months.
- 1987 : SAMPWEIGHT