Iodine in Health and Disease: A Comprehensive Review

Area of Science:

• Endocrinology and Nutritional Science
• Public Health
• Physiology

Background:

• Iodine is an essential micronutrient vital for thyroid hormone synthesis, impacting metabolism, neurodevelopment, and immunity.
• Both iodine deficiency and excess pose significant global health challenges, despite efforts to improve supply.
• Emerging research highlights extrathyroidal roles of iodine in immunomodulation and antioxidant functions.

Purpose of the Study:

• To review iodine physiology, including its role in thyroid hormone synthesis and extrathyroidal functions.
• To summarize dietary sources, global intake patterns, and methods for assessing iodine status.
• To examine the health consequences of iodine imbalance and evaluate public health strategies.

Main Methods:

• Literature review of iodine physiology, dietary sources, and assessment methods.
• Analysis of clinical consequences of iodine deficiency and excess.
• Evaluation of public health interventions like salt iodization and supplementation.

Main Results:

• Iodine imbalance leads to goiter, hypothyroidism, impaired neurodevelopment (deficiency), and thyroid dysfunction or autoimmunity (excess).
• Vulnerable populations like pregnant women and infants require special attention regarding iodine status.
• Salt reduction initiatives present a new challenge to maintaining adequate iodine intake.

Conclusions:

• Optimal iodine intake is essential for thyroid health and population well-being.
• Coordinated monitoring and adaptive public health policies are necessary to address iodine status challenges.
• Understanding iodine's multifaceted roles is key to preventing deficiency and excess.