Iodine
Sole precursor to thyroid hormones T3 and T4. UK surveys (NDNS) consistently show iodine inadequacy - particularly in women avoiding dairy and in vegans. 150mcg = 100% NRV.
Mechanism
Iodine is the sole substrate for thyroid hormone synthesis. The thyroid gland concentrates iodine against a steep gradient via the sodium-iodide symporter (NIS), incorporating it into tyrosine residues on thyroglobulin to form T3 and T4. These hormones regulate basal metabolic rate, thermogenesis, protein synthesis, and - critically - brain development in utero and early childhood.
The UK National Diet and Nutrition Survey (NDNS) consistently identifies iodine as a nutrient of concern, with median intakes in women falling below the Lower Reference Nutrient Intake. Declining consumption of dairy products (the primary dietary source) has worsened this trend. Insufficient iodine intake is associated with reduced thyroid hormone output - reduced metabolic rate, fatigue, and cognitive fog - without meeting the clinical threshold for diagnosis.
Key Benefits
- Sole substrate for thyroid hormone T3 and T4 synthesis
- Governs basal metabolic rate and thermogenesis
- UK women frequently inadequate - dairy avoidance worsens the trend
- Supports brain development and neurological function
- 150mcg = 100% NRV
Iodine
150mcgPotassium iodide - pharmaceutical grade
Any time of day. Iodine is water-soluble and does not require timing with food. UK women of reproductive age have particularly high rates of inadequate intake.