The influence of dietary iodine on lithium blood level, serum T4 and thyroid gland weight.

Lithium is both antithyroid and goitrogenic. The relationship between lithium and iodine has been assessed in rats fed diets containing different iodine content. Chronic lithium treatment caused increase in thyroid gland weight in animals on low and high iodine diets. A reciprocal relationship surfaced between serum lithium levels and dietary iodine content. Animals on low-iodine diet had lower serum lithium levels. The data support other evidence that lithium likely inhibits organification of iodine by a Wolff-Chaikoff-like effect.