Nutritional Status of Iodine and Association with Iron, Selenium, and Zinc in Population Studies: A Systematic Review...

Micronutrient deficiencies are not always present in individuals independently and may occur in association with other deficiency processes.

Verify the association between the nutritional status of iodine and that of iron, selenium, and zinc in population studies.

A bibliographic search was carried out in Medline, Web of Science, and CINAHL databases, without date and language restrictions, using English search terms and their synonyms. The search terms were joined by the Boolean operator AND while the respective synonyms were connected by OR following the PRISMA guidelines.

A total of 40 articles were included. The studies were published between 1993 and 2025, mostly involving both sexes and the main age groups were children and adolescents. Among the micronutrients analyzed, selenium stood out, being evaluated in 55.0% (n = 22) of the studies, followed by iron in 37.5% (n = 15) and zinc in 27.5% (n = 11). The most commonly used methods for assessing nutritional status were serum selenium, followed by urinary selenium. For iron, hemoglobin, ferritin, and serum iron were used in 73.3% (n = 11), 60.0% (n = 9), and 46.7% (n = 7) of the studies, respectively. For zinc, serum concentration was the most frequently used method; however, in one study, urinary zinc was evaluated. Overall, the nutritional status of iodine was associated with that of selenium, iron, and zinc, although this trend was not observed in some studies.

The coexistence of deficiency processes in an individual still needs to be further elucidated. Combined strategies that effectively combat, prevent, and treat these micronutrient deficiencies must consider the possible interactions between them.