The nutrients and dietary components examined include:
Nutrients currently targeted by the WIC program—calcium, iron, vitamin A, vitamin C, and protein;
Macronutrients—food energy and the percentage of food energy from protein, carbohydrate, and fat; and
Other nutrients and dietary components considered of public health significance—selenium, magnesium, phosphorus, sodium, potassium, vitamin E, thiamin, riboflavin, niacin, vitamin B6, vitamin B12, folate, fiber, and cholesterol; also saturated fat and added sugars as a percentage of food energy intake.
An important issue is to ensure that comparable units for each nutrient are used among the various resources used. Specific issues arise regarding the units for vitamin E, niacin and folate.
Vitamin E—The DRIs report vitamin E as AT [(alpha)-tocopherol]. Thus, the EARs for vitamin E apply only to RRR-(alpha)-tocopherol, the form of (alpha)-tocopherol that occurs naturally in foods, and the 2R-stereoisomeric forms, a portion of the (alpha)-tocopherol used in fortified foods and dietary supplements. Analysis of dietary intake (CSFII) was based on data in which the units for reporting vitamin E were ATE [(alpha)-tocopherol equivalents which include the contribution of eight naturally occurring tocopherols]. Because of the differences in the units between the intake data and the EARs, the estimated prevalences of inadequacy of vitamin E intakes in this report are likely to be underestimates.
Niacin—Analysis of dietary intake of niacin was based solely on preformed niacin; however, the EAR is based on niacin equivalents (which allows for some conversion of the amino acid tryptophan to niacin). Thus, the estimated prevalence of inadequacy of niacin intakes is likely to be an overestimate.
Folate in Dietary Folate Equivalents—The DRIs report folate as microgram DFE (Dietary Folate Equivalents). Dietary intake data (CSFII) reports folate in micrograms. For this report, the amount of folate was calculated by applying the nutrient values from the Food and Nutrient Database for Dietary Studies (FSRG, 2004) to the CSFII folate data. The CSFII data included some food codes not included in the FNDDS; for those food codes the committee applied conversions developed by USDA’s Center for Nutrition Policy and Promotion (CNPP database received from Tracy Von Ins, OANE, FNS, USDA, October, 2004) to obtain the total amount of folate (as microgram DFE) consumed per day for all foods eaten. The values of “folate as dietary folate equivalents” were compared to the EARs.