Topic overview

Start with the big picture

The lesson surveys five trace elements through their functions, dietary reference values where provided, and clinically important imbalances. Iodine supports T3 and T4 synthesis; inadequate intake can affect thyroid function and neurodevelopment, while excess may also disrupt thyroid activity. Selenium contributes to antioxidant and thyroid pathways, with deficiency and toxicity linked to characteristic findings. Copper is part of several enzymes, and both deficiency and overload have important clinical consequences. Fluoride supports enamel and bone, whereas chronic excess can affect teeth and the skeleton. Chromium is described as a contributor to insulin signaling, with deficiency associated with impaired glucose tolerance. The topic also introduces goitrogens and interactions among trace elements.