Serum ferritin levels in a sample of older participants in the Greek HYDRIA survey: associations with sociodemographic and lifestyle parameters including dietary iron intake and Mediterranean diet score

Iron deficiency (ID) represents the most prevalent nutritional disorder and a major public health concern. As part of the HYDRIA 2013-2014 National Health and Nutrition study, a cross-sectional survey of a nationally representative sample of adults in Greece, serum ferritin levels (SFL) were measured in participants aged ≥ 55 years, and dietary intake was assessed using two non-consecutive 24-h dietary recalls per participant. The study aimed to evaluate SFL, determine the prevalence of ID among older adults and explore associations with dietary iron intake and adherence to the Mediterranean diet (MD). Among individuals over 55 years, ID prevalence was 6·5 % for SFL < 15 ng/ml and 12·7 % for SFL < 30 ng/ml. SFL were significantly associated with sex and age (<i>P</i> < 0·001), with men showing higher SFL than women. Advancing age, particularly among individuals over 74 years, increased the risk of ID. Dietary iron intake declined with age, and women had significantly lower intake than men (<i>P</i> < 0·001). Overall, 57·2 % of participants had inadequate daily iron intake. SFL were not associated with total or haem iron intake. High adherence to MD was associated with higher energy-adjusted total iron intake but lower haem iron intake. Weighted logistic regression for SFL < 15 ng/ml showed that MD adherence was significantly associated with reduced odds of ID (<i>P</i> = 0·007), likely due to the protective effect of intermediate adherence (OR = 0·10, <i>P</i> = 0·002). Conclusively, while ID prevalence among older adults in Greece is low, over half of the population presents inadequate daily iron intake, especially women. High adherence to MD may have a protective effect against ID.