Diet History Questionnaire: Database Revision History

Background

The foundation of the nutrient database for the DHQ comes from the USDA survey nutrient food codes found in the 1994-96 Continuing Survey of Food Intake by Individuals (CSFII)1. Through a matching process overseen by Dr. Beth Dixon (currently at NYU, but previously at NCI) in conjunction with Thea Zimmerman at Westat, survey food codes required to create the DHQ database in CSFII were matched to a food code within the University of Minnesota's Nutrient Data System for Research (NDS-R). NDS-R has an extensive database that includes more nutrients than are available from the USDA survey food codes. It was through this process, documented in a recent publication2, that both tocopherols and carotenoids were added to the DHQ.

Specific Additions/Changes

1. There are very minor changes to all the nutrients values due to refinements in programming.
2. The order of the nutrients in the Diet*Calc database was modified to better group like or related nutrients and to place all NDS-R based nutrients at the end.
3. There is a fix to the number of pyramid servings counted for French fries based on discussions with USDA. This change will serve to lower values for pyramid servings of white potatoes and total vegetables.
4. Because the USDA data assumed white grapefruit as the default for all grapefruit intake, a fix was devised to allow for carotenoid values for both pink and white grapefruit to be included. No national data were available to determine whether pink or white grapefruit are eaten more frequently, therefore, the nutrient values for these two varieties were equally weighted to compute values for the database.
5. Improved labels for nutrients. Most nutrients are based on CSFII data. Those nutrients added from NDS-R data, are now clearly labeled as, "(NDS-R)." For the few nutrients for which there exists both CSFII and NDS-R values, the phrase, "(CSFII)," was added to the label.
6. Clearly marked units have been included for retinol activity equivalents (RAE).
7. We have updated all NDS-R based nutrients using the most recent database (NDS-R 4.06_34) and have added 15 new nutrients from NDS-R:
   1. Vitamin A, total activity (mcg RAE)
   2. Beta carotene equivalents (mcg)
   3. Vitamin E - total alpha-tocopherol (mg)
   4. Methionine (g)
   5. Folate (mcg)
   6. Dietary folate equivalents (mcg)
   7. Natural food folate (mcg)
   8. Synthetic folate (mcg)
   9. Total dietary fiber (g)
   10. Insoluble fiber (g)
   11. Soluble dietary fiber (g)
   12. Total trans-fatty acids (g)
   13. 16:1 Trans-hexadecenoic acid (g)
   14. 18:1 Trans-octadecenoic acid (g)
   15. 18:2 Trans-octadecadienoic acid (g)

   Please note: if you are using the NDS-R-based values for individual carotenoids, tocopherols, or folates, and you are also interested in the corresponding total intakes of vitamin A, carotenoids, vitamin E, or folate, it is best if you use the NDS-R-based values in all cases because the parts and the sums will be based on the same nutrient database.

8. In the latest version of NDS-R, what was previously considered to be vitamin E (in alpha-tocopherol equivalents (ATE)) was revised based on the recent DRI report, "Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids." The new vitamin E value included in NDS-R and in the current Diet*Calc database consists of alpha-tocopherol (mg) only. Other tocopherols previously included in the calculation of vitamin E activity are no longer considered to have any vitamin E activity. So, while the previous version of Diet*Calc had a value for both vitamin E (ATE) and alpha-tocopherol (mg), the current version has a value for vitamin E that consists of alpha-tocopherol only -- they are one in the same. The database no longer has two separate values for vitamin E and alpha-tocopherol.
9. The values for vitamin A and beta-carotene coming from vitamin supplements have been updated to reflect the most recent conversions recommended in the recent DRI report, "Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids." Units are now in retinol activity equivalents (RAE).

References

1. Subar AF, Midthune D, Kulldorff M, Brown CC, Thompson FE, Kipnis V, Schatzkin A. An evaluation of alternative approaches to assigning nutrient values to food groups in food frequency questionnaires. Am J Epidemiol. 2000;152;279-286.
2. Dixon LB, Zimmerman TP, Kahle LL, Subar AF. Adding carotenoids to the NCI Diet History Questionnaire Database. J Food Comp Anal. 2003;16:269-280.