 Dietary vitamin D Dietary factors included in our analyses were measured at the baseline visit. Baseline 24-hour dietary recalls were obtained using the US Department of Agriculture USDA Automated Multiple Pass Method, a computerized structured interview.37 Measurement aids used included measuring cups, spoons, ruler and an illustrated Food Model Booklet. Two recalls were administered in-person by trained interviewers, 4-10 days apart. Trained nutrition professionals used Survey Net, matching foods consumed with 8-digit codes from the Food and Nutrient Database for Dietary Studies FNDDS version 3.0,38 and My pyramid equivalents database for food groups MPED 2: Dietary vitamin D was among the nutrients made available by the FNDDS, from which daily values could be estimated and expressed in μgd, using the average from the two 24-hr recalls conducted at baseline. 