Temporal changes in micronutrient intake among United States Adults, NHANES 2003 through 2018: A cross-sectional study

Abstract

Background: Changes in the United States food supply and food choices make examination of temporal changes in micronutrient intake and their effect on meeting nutrient recommendations necessary.

Objectives: This study aimed to examine 15-year trends of the contribution of foods and beverages (FB) and dietary supplements (DSs) to meeting nutrient recommendations among United States adults aged 19 y or older and compare usual mean intake distributions of FB alone with those of FB+DSs with dietary reference intakes [percentage below the estimated average requirement (%<EAR) or above the adequate intake (%>AI)].

Methods: This cross-sectional study used food, beverage, and DSs intake data from NHANES 2003-2018 (N = 39,925) to determine usual mean intakes for 21 micronutrients. Changes in intakes from FB and from FB+DSs, by sex, were compared in a time-trend analysis of 2-y cycles. Changes in mean intake as %<EAR/>AI were determined.

Results: Over the time studied, United States adults underconsumed vitamins A, C, D, E, and K; calcium; potassium; magnesium; and choline, even when DSs intake was included. Sodium was overconsumed. In males, there were significant increases in %<EAR for thiamin, riboflavin, vitamin C, iron, copper, and zinc for intakes from FB. When FB+DSs were considered, there were significant increases in %<EAR for thiamin, riboflavin, vitamin B-12, vitamin C, copper, and zinc and significant decreases in %<EAR for vitamins D and E. In females, there were significant increases in %<EAR for vitamin C and zinc for intakes from FB and from FB+DSs; significant decreases in %<EAR for vitamins D and E, and magnesium for intakes from FB; and a significant decrease in %<EAR for vitamins A and E from FB+DSs.

Conclusions: Although some progress has been made, nutrient intake and percentage of the population meeting nutritional recommendations among United States adults has changed little over the 15 y studied.

Keywords: adequate intake; dietary recommendations; dietary supplements; estimated average requirement; nutrient intake; underconsumed nutrients.