There were examined 119 patients of gastroenterological profile, who, according to the results of microbiological examination of scraping from tongue and biopsy material of digestive tract and stomach, were divided into three groups: 1 group – patients with oropharyngeal candidiasis and surface candidiasis of mucous tunic, 2 group – patients with invasion of Candida fungi in mucous tunic, 3 group – patients without oropharyngeal candidiasis and without growth of fungi in biopsy material. The status of iodine provision was studied in 78 persons. The results of research revealed that at structural changes of thyroid gland the dominating position in patients with candidiasis of mucous tunic occupies the nodular goiter– 29,31% and 36,36% for 1 and 2 group respectively, whereas in 3 group the frequency of nodular goiter was 11,76%, at that hyperplasia and nodular goiter in patients with fungi invasion in mucous tunic was revealed 2,6 times more often comparing with patients without candidiasis (χ2=4,01; р<0,05). In patients with oropharyngeal and surface candidiasis and invasive candidiasis of mucous tunic of the upper part of digestive tract the hard degree of iodine nutrition deficiency with thyroglobulin level higher than 40 ng/ml was revealed in more than half of cases. At that the frequency of hard iodine deficiency at fungi invasion in mucous tunic 4,2 times higher comparing with patients without candidiasis of mucous tunic (F=0,024; р<0,05).So, the concomitant comorbid state with pathology of thyroid gland and iodine deficiency is an aggravating factor in the course of candida infection that is necessary to be taken into account at clinical monitoring of patients with candidiasis of mucous tunic of the upper part of gastrointestinal tract.