(OR19-06-26) Folic Acid Supplementation Attenuates Serum Zinc Concentration and Its Association With Dietary Zinc Intake: NHANES 2011–2016

Monday, July 27, 2026

11:30 AM - 11:42 AM ET

Location: National Harbor 4-5

Emerging Leaders in Nutrition Science Poster Competition

Presenting Author(s)

Yuyi Chen, MSPH, RD (she/her/hers)

PhD Student
University of California, Davis
Davis, California, United States

Disclosure(s): No relevant financial relationship(s) with ineligible companies to disclose.

Co-Author(s)

AH

Andrew Hall

University of California, Davis, United States
Amy R. Nichols, PhD, MS, RDN (she/her/hers)

Assistant Professor
University of California, Davis
Davis, California, United States

Disclosure(s):

Yuyi Chen, MSPH, RD: No relevant financial relationship(s) with ineligible companies to disclose.

Amy R. Nichols, PhD, MS, RDN: No relevant financial relationship(s) with ineligible companies to disclose.

Objectives: Zinc deficiency remains a global health concern, yet accurate population-level assessment is challenging. The Miller model estimates total absorbable zinc (TAZ) from food intake but does not account for supplemental micronutrients that may influence zinc bioavailability.

We evaluated the relationship between TAZ and serum zinc concentration (SZC) in the U.S. population aged ≥6 years and examined whether folic acid, zinc, and iron supplements modify this relationship using NHANES 2011–2016 data.

Methods: We analyzed 518 participants with complete dietary recalls, supplement data, and measured SZC. TAZ was estimated using the Miller model. Multivariable linear regression assessed associations between TAZ, supplement use, and SZC, adjusting for sociodemographic, lifestyle, health, and laboratory covariates.

Results: Median SZC was 80.7 µg/dL and median TAZ was 2.55 mg/d. TAZ was not independently associated with SZC in adjusted models (β = -1.36, p = 0.481). However, folic acid supplementation was inversely associated with SZC in a dose-dependent manner (β = -0.035 per 100 µg/d, p < 0.001). Significant interactions emerged between folic acid supplementation and both TAZ (β = 0.009, p = 0.017) and zinc supplementation (β = 0.0004, p < 0.001), indicating that folic acid modifies the zinc intake–biomarker relationship. Zinc supplementation alone was not significantly associated with SZC (β = 0.036, p = 0.649). Additionally, diabetes was positively associated with SZC (β = 4.38, p = 0.017), while high physical activity was inversely associated (β = -2.91, p = 0.019). Findings remained robust across sensitivity analyses.

Conclusions: Folic acid supplementation is associated with lower SZC and attenuates the zinc intake–biomarker relationship at commonly consumed doses. The disconnect between modeled absorption and SZC highlights challenges in population zinc assessment. Zinc co-supplementation may be warranted for individuals taking high-dose folic acid, particularly pregnant and lactating women.

Funding Sources: N/A