The Prevalence of Nutritional Imbalances in the US Population Over Time: Biomarker Data from the Cross-Sectional National Health and Nutrition Examination Survey (NHANES 1999-2000 through August 2021-August 2023).

BACKGROUND

Tracking the prevalence of imbalances for essential nutrients over time provides insight into nutritional status changes and highlights vulnerabilities of demographic subgroups. Consolidated information for a broad range of biomarkers in the US population is missing.

OBJECTIVES

We aimed to describe nutritional deficiency and excess prevalence trends for 12 biomarkers of water- and fat-soluble vitamins and iron status in the US population participating in the NHANES 1999-2023 after adjusting for demographic changes over time.

METHODS

We estimated the prevalence of deficiency (vitamins A, B-6, B-12, C, D, and E, as well as iron), insufficiency [vitamins B-6, B-9 (folate), B-12, C, and D], and excess (vitamins A and D as well as iron). We assessed trends as overall change in prevalence using logistic regression (unadjusted and adjusted for age, sex, and race/Hispanic origin) and as linear trend (if overall change was significant).

RESULTS

After adjusting for demographic changes, we observed small (typically <5 percentage points) temporal changes (significant linear trends) in the prevalence of deficiency and/or insufficiency for vitamin B-12 and methylmalonic acid (≥20 y), and for vitamin E and 25-hydroxyvitamin D (25OHD) (≥6 y). The prevalence of folate insufficiency (red blood cell folate (RBF) <748 nmol/L) and iron deficiency (ferritin ≤15 ng/mL) increased from 15.7% to 21.4% and from 11.6% to 17.4%, respectively, in women of reproductive age. The prevalence of excess vitamin D (25OHD >125 nmol/L) increased from <1% to 8.06% in persons ≥6 y, with the highest prevalence in adult subgroups (16.2% in supplement users, 13.2% in females, and 12.3% in non-Hispanic White persons).

CONCLUSIONS

The large increases in excess 25OHD concentrations and modest increases in low ferritin and RBF concentrations merit attention and highlight the importance of providing gold standard data to continuously monitor the nutritional status of the US population and of subpopulations.