INFLUENCE OF KNOWLEDGE ON IODINE CONTENT IN FOODSTUFFS AND PROPHYLACTIC USAGE OF IODIZED SALT ON URINARY IODINE EXCRETION AND THYROID VOLUME OF ADULTS IN SOUTHERN GERMANY

Thyroid volume, urinary iodine excretion as well as personal nutrition al knowledge and individual iodine prophylaxis were determined during a health education program on iodine deficiency and prophylaxis in 199 2. Participants were 472 male and 568 female (mean age 27.7 years) stu dents and employees of five universities in the southern part of Germa ny. The study aimed to clarify the relationship between personal knowl edge on iodine, individual iodine prophylaxis and parameters of iodine deficiency (thyroid volume, iodine excretion) in a well known iodine deficient area. Mean thyroid volume (mean +/- SD) was 19.7 +/- 8.3 mi in males and 15.8 +/- 7.1 mi in females. 25.5 % of females and 19.9 % of males showed thyroid volume above the upper normal values. Total me an urinary iodine excretion was 70.7 +/- 42 mu g I/g creatinine reflec ting WHO-grade-I iodine deficiency. 80.8 % of total subjects used iodi zed salt and 43.2 % stated to consume salt-waterish to meet their iodi ne requirement. The female non-users had significantly lower iodine ex cretion (no iodized salt, no salt-water fish: 61.4 +/- 31.3 vs. +iodiz ed salt, +salt-water fish: 83.9 +/-47.6 mu g I/g creatinine; p < 0.05) , however, thyroid volume was identical in these groups. The area of r esidence over the last 10 years did not significantly influence the th yroid volume. The goiter incidence increased with age. Although our st udy population was highly educated (81.8 % students) and the subjects were provided with educational brochures immediately prior to the stud y, knowledge about iodine content of food was poor. We conclude that d espite a high degree of voluntary iodine prophylaxis and educational p rograms the iodine intake is insufficient. The use of iodized salt in households, cafeterias, and also in food manufacturing must be increas ed for sufficient iodine prophylaxis.