Repeated cross-sectional and longitudinal study of dietary mineral intake status in Iranian adults: Tehran lipid and glucose study.

Background: Mineral deficiencies are significant public health concerns worldwide, contributing to the development and progression of non-communicable diseases (NCDs). We evaluated longitudinal adequacy of mineral intakes among Iranian adults.

Methods: Adult (aged ≥ 18) participants were included in the repeated cross-sectional analysis from 2006-2008 to 2018-2022. Dietary intake was assessed using a validated Food Frequency Questionnaire (FFQ). Adequacy of minerals intake, including calcium, iron, magnesium, zinc, copper, manganese, selenium, and chromium, were evaluated against the European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines. Longitudinal trends of mineral intakes were evaluated using repeated measures analysis of variance in a cohort of 4384 participants (42% men; mean age 40.8 ± 12.8 years).

Results: Calcium inadequacy increased markedly from 39.6% in 2006-2008 to 68.6% in 2018-2022, with higher rates among women (74.1%) and older adults (75.0%). Iron inadequacy, mainly affecting women, increased from 14.5 to 39.1% over the same period. Although magnesium inadequacy remained high overall, it reached 34.2% in 2018-2022. In contrast, manganese intake was rarely inadequate. Zinc, copper, selenium, and chromium inadequacies showed fluctuations, but mean levels were generally closer to recommended values despite notable gender disparities.

Conclusions: The study indicates significant and worsening mineral intake inadequacies among Iranian adults, particularly for calcium and iron. Further long-term studies are needed to guide interventions, such as dietary education, food fortification, and policy measures aimed at improving micronutrient intake across diverse age and gender groups.