title: Thyroid dysfunction following a kelp-containing marketed diet.
abstract: Complementary medications and herbal medicine for weight loss have become very popular. We report a case of thyroid dysfunction following the ingestion of a kelp-containing marketed diet in a 45-year-old woman with no previous thyroid disease. Signs of hyperthyroidism occurred shortly after a kelp-containing diet. Hyperthyroidism lasted 2 months and was followed by an overt hypothyroidism. The thyroid scintiscan exhibited an extremely low uptake and colour-Doppler ultrasonography revealed multiple small areas of pulsatile flow. After 3 months of levothyroxine substitutive therapy, normal thyroid function was recovered after levothyroxine discontinuation. This clinical history is compatible with a case of iodine-induced thyrotoxicosis followed by prolonged block of the sodium-iodide symporter activity as a consequence of excessive iodine consumption from kelp. Consumers of marketed diets containing kelp or other iodine-rich ingredients should be advised of the risk to develop a thyroid dysfunction also in the absence of underlying thyroid disease.
authors.affiliation: A.O.R.N. dei Colli Hospital, Naples, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Di Matola
authors.affiliation: University of Salerno, Baronissi, Salerno, Italy.
authors.forename: Pio
authors.initials: P
authors.lastname: Zeppa
authors.affiliation: University of Molise, Campobasso, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gasperi
authors.affiliation: University of Salerno, Baronissi, Salerno, Italy.
authors.forename: Mario
authors.identifier: http://orcid.org/0000-0002-4583-5971
authors.initials: M
authors.lastname: Vitale
mesh_terms: D004038:Diet, Reducing / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000139:chemically induced*; D007037:Hypothyroidism / Q000139:chemically induced* / Q000188:drug therapy; D007455:Iodine / Q000009:adverse effects*; D044423:Kelp; D008875:Middle Aged; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013971:Thyrotoxicosis / Q000139:chemically induced; D013974:Thyroxine / Q000627:therapeutic use; D014463:Ultrasonography
chemical_list: D007455:Iodine; D013974:Thyroxine