Absolutely true. Most of the world's population is deficient in iodine. Its lack manifests itself in different ways in different people, which gives rise to what appears to be a wide range of different pathologies, which "modern" medicine treats as separate conditions.
Prostate and Breast NEED iodine. Lack of it is consistent with prostatic and mammary carcinomae, which are not-infrequently reversed by orthoiodosupplementation.