(P14-080-23) Dietary Trends in Total Usual Intake of Vitamin C Using NHANES 1999–2018: A Curtain-Raiser to Dietary Intake Visualizers in Nutrition Research

Objectives: The NHANES provide necessary data to estimate dietary intake in the US that inform research and public policy. Currently, there are no interactive data visualizers to explore trends in dietary intake from the NHANES. The objective of this study was to display trends in usual vitamin C intake derived from the NHANES 1999-2018 via a new digital data visualization dashboard called the Dietary Intake Evaluation Trends (DIET) dashboard.

Methods: Nonpregnant and nonlactating participants in the NHANES 1999-2018 (≥ 2y) who provided at least one reliable dietary recall were included in the analyses. Usual intake (UI) of vitamin C from foods, beverages, and supplements was estimated using the NCI method across age, gender, and race/ethnicity subgroups. The proportion of those with inadequate vitamin C intake (% < Estimated Average Requirement(EAR)) was estimated using the cut-point approach. The data visualization dashboard can display output in a line graph format as well as customizable tables available for download. Customization options of the dashboard include displaying output restricted to subgroups of interest and selecting relevant summary statistics. SAS version 9.4 was used to perform the analyses and the dashboard was developed in Tableau Public 2022.3.

Results: Mean [SE] vitamin C UI decreased across all race/ethnicity and gender groups between 1999 and 2018. The greatest decrease from 1999-2000 to 2017-2018 was observed in non-Hispanic white (NHW) females (220[9] to 139[9] mg/d) and males (231[22] to 150[9] mg/d). The second greatest decline in intake was among non-Hispanic blacks (NHB) (females: 136[9] mg/d to 115[8]; males: from 148[7] mg/d to 116[7] mg/d).  Consequently, the proportion who consumed below the EAR for vitamin C increased from 1999 - 2018 among NHW females (19[1]% to 32[2]%) and males (22[2]% to 37[2]%).  The proportion who consumed below the EAR for vitamin C increased from 1999 - 2018 among NHB females (19[1]% to 32[2]%) and males(22[2]% to 39[2]%).

Conclusions: The declines in total UI of vitamin C over the past 20 years may indicate a need to consider vitamin C as a nutrient of public health concern. The DIET dashboard serves as a tool to explore trends in dietary intake and can be updated as additional NHANES survey cycles are published.

Funding Sources: Texas Woman's University Research Enhancement Program (REP)