Tabriz University of Medical Sciences Health Promotion Perspectives 2228-6497 16 3 2026 11 05 Changes in Micronutrient Intake and Associated Determinants in Iran: A Longitudinal Cohort Analysis Using PERSIAN Cohort Data 378 395 10.34172/hpp.45347 EN Habib Allah Shahriyari https://orcid.org/0000-0001-8999-044X Neda Izadi Shahab Rezaeian Yahya Pasdar Fatemeh Khosravi Shademani Amir Bagheri Sareh Eghtesad Maryam Sharafkhah Amir Houshang Mehrparvar Masoumeh Ghoddusi Johari Ali Esmaeili Nadimi Elaheh Foroumandi Iraj Mohebbi Mahdi Mohammadi Motahareh Kheradmand Ali Ahmadi Ali Reza Safarpour Bahman Cheraghian Farahnaz Joukar Babak Pezeshki Seyed Bahman Panahande Bakhtiar Piroozi Azim Nejatizadeh Elnaz Faramarzi Farhad Pourfarzi Farid Najafi https://orcid.org/0000-0001-8530-7180 Journal Article 10.34172/hpp.45347 2025 10 18 2026 06 15 Introduction: Using data from the Prospective Epidemiological Research Studies in Iran (PERSIAN) Cohort, we assessed longitudinal changes in calcium, iron, and zinc intake between baseline (2015) and reassessment (2021) phases and examined their determinants. Methods: We analyzed longitudinal data from 32,220 participants aged 35–70 years in the PERSIAN Cohort at baseline (2015) and reassessment (2021). Dietary intake was assessed using a validated 113-item Food Frequency Questionnaire (FFQ), with caution warranted for micronutrient-level estimates. A four-level multilevel model was applied, with repeated measurements (level 1) nested within individuals, households (level 2), residence types (level 3), and interview centers/provinces (level 4). Intraclass correlation coefficients (ICCs) were calculated to estimate the proportion of total variance in mineral intake attributable to each hierarchical level. Results: Unadjusted paired analyses showed mean daily intakes of calcium, iron, and zinc decreased by 142.5 mg, 1.7 mg, and 1.1 mg, respectively, between baseline and reassessment. In the fully adjusted four-level multilevel model, intake decreased by 151.37 mg/day for calcium, 1.85 mg/day for iron, and 1.25 mg/day for zinc during reassessment. Women consumed 184.25 mg/day less calcium than men, and participants in the highest socioeconomic status group had higher intakes of all three minerals compared with the lowest group. ICCs indicated that 23.9% of calcium variance, 31.7% of iron variance, and 11.7% of zinc variance were attributable to interview centers, with additional 19.9%, 18.4%, and 27.9% attributable to households, respectively. Conclusions: The decline coincided with challenges and policy changes in Iran, which may have contributed to dietary shifts, although these factors were not measured. These findings highlight the need for interventions to improve mineral intake.