Iodine content in plant food is lower due to a low iodine concentration in soil. Value of iodine in urine (average sample of 24-h urine volume) as a marker of iodine deficiency was assessed in probands on alternative nutrition (15 vegetari- ans /plants food + dairy products + eggs/, 6 vegans /exclusively plant food/) and compared to subjects on traditional nutrition (n = 24). Iodine excretion was nonsignificantly lower in vegetarians and significantly reduced in vegans (131.0 mg/l and 59.6 mg/l vs 169.2 mg/l in traditional nutrition group). Half of vegetarians, 100% of vegans vs 21% of traditional nutrition subjects suffer from iodine deficiency (values below 100 mg/l). The results show that under condition of alternative nutrition the high prevalence of iodine deficiency is a consequence of prevailingly or exclusively plant consumption and no intake of sea products as well as reduced intake of salt.

        Key words: iodine - vegetarians - vegans