Iodine
Major Functions
Thyroid hormones - Maintenance of metabolism - Cognitive function
In every dose
150mcg (equal to 2 cups of yogurt or 6 slices of fortified white bread)
What’s in it for my brain?
Brain scans in people with iodine deficiency have shown that structures within the brain such as the hippocampus and neurotransmitters (chemicals in the brain) are affected by iodine deficiency. It’s widely recognised that iodine contributes to normal cognitive function; the exact mechanism is unclear, but it’s thought to be related to gene expression.
Fringe benefits
Iodine helps to make thyroid hormones, which control our metabolic rate
Essential for optimal fertility
Plays well with
Selenium for thyroid function
Folate for women trying to conceive
B12 and other B vits for those on plant-based diets
Clever stuff
Iodine is especially important in foetal and childhood development, as it is essential for thyroid hormone synthesis, which is important in normal brain development. A trial of 310 mildly deficient school children found that iodine supplementation in people who are deficient improved information processing, fine motor skills and problem solving.
Evidence
Here’s a handful of relevant scientific studies on iodine.
Zimmermann, M. B., Connolly, K., Bozo, M., Bridson, J., Rohner, F., & Grimci, L. (2006). Iodine supplementation improves cognition in iodine-deficient schoolchildren in Albania: a randomized, controlled, double-blind study. The American journal of clinical nutrition, 83(1), 108-114.
Redman, K., Ruffman, T., Fitzgerald, P., & Skeaff, S. (2016). Iodine deficiency and the brain: Effects and mechanisms. Critical reviews in food science and nutrition, 56(16), 2695-2713.
Bouga, M., Lean, M. E., & Combet, E. (2018). Iodine and pregnancy—a qualitative study focusing on dietary guidance and information. Nutrients, 10(4), 408.
Gordon, R. C., Rose, M. C., Skeaff, S. A., Gray, A. R., Morgan, K. M., & Ruffman, T. (2009). Iodine supplementation improves cognition in mildly iodine-deficient children. The American journal of clinical nutrition, 90(5), 1264-1271.
Hernández, M., Wilson, K. L., Combet, E., & Wardlaw, J. M. (2013). Brain findings associated with iodine deficiency identified by magnetic resonance methods: a systematic review. Open Journal of Radiology, 3(4), 180-195.
Fitzgerald, P. C. E. (2012). The effect of iodine supplementation on cognition of mildly iodine deficient young New Zealand adults (Doctoral dissertation, University of Otago).
Beydoun, M. A., Beydoun, H. A., Kitner-Triolo, M. H., Kaufman, J. S., Evans, M. K., & Zonderman, A. B. (2013). Thyroid hormones are associated with cognitive function: moderation by sex, race, and depressive symptoms. The Journal of Clinical Endocrinology & Metabolism, 98(8), 3470-3481.