Further Observations on the Occurrence of Iodine in Relation to Endemic Goitre in New Zealand and on Iodine Metabolism

Abstract

1. Most artificial manures are found to have some effect in increasing the iodine content of crops, particularly superphosphate.2. Marked differences are found between the iodine contents of Samoan and New Zealand foodstuffs corresponding to the non-goitrous condition of Samoa and the partial endemicity of New Zealand.3. Investigation of the dietaries of fifteen residential institutions showed that improvement in provision of iodine was necessary in many cases by using fish at least twice a week, raising the daily ration of milk to 1 pint per head, and employing iodised salt for table and culinary purposes.4. Dietetic experiments indicate (i) that on a change of diet adjustment of iodine metabolism may take a considerable time, (ii) that iodised salt is most effective in promoting storage of iodine when associated with a meat diet.5. Iodine excretion is found to decrease much more rapidly under fasting than on a diet very low in iodine.6. Iodised salt has the effect of adjusting the excretion of goitrous adults to the normal non-goitrous value.7. The iodine content of the blood is found to be lower than normal in cases of simple colloid and simple nodular goitre, though it may range from low to abnormally high in cases of Graves' disease. In all types of goitre the thyroid gland is low in iodine.8. The ratio of thyroid iodine to total bodily iodine is about 12 per cent. in the case of the white rat under ordinary conditions, but the ratio is found to vary considerably with the iodine intake.9. Great differences in the ratio of the weight of the thyroid gland to that of the whole body are found among different species of animals, the ratio being higher for the dog than for the monkey.10. Variations in commercial samples of iodised salts are recorded and discussed.11. Data are given in regard to the iodine and chlorine content of rainwater in different localities.

Studies on Endemic and Experimental Goitre

“…In a test of New Zealand cabbage in the winter of 1931 we found only a slight activity (Hercus and Aitken, 1933). Our aim was the production of large goitres several grams in weight.…”

“…INTRODUCTION THE subject-matter of this paper is a continuation of the researches on the subject of goitre carried out in this University (see papers by Hercus, Benson and Carter, 1925;Hercus and Roberts, 1927;Hercus, Aitken, Thomson and Cox, 1931;Hercus and Aitken, 1933). In the present paper the relation between lack of iodine and goitre is discussed, and the thesis that lack of iodine is the predominant factor in the production of endemic goitre is supported by the results of a survey of urinary excretion of iodine in certain New Zealand districts and in the islands of Samoa.…”

“…ANALYTICAL METHOD The method previously described by Hercus and Aitken (1933) was modified in several respects to eliminate certain errors. The method of combustion previously used involved heating in an open crucible and was unsatisfactory in several ways.…”

The mineral composition of crops with particular reference to the soils in which they were grown : a review and compilation /

“…OF AGRICULTUKE interesting observation "that stock make every effort to break bounds in order to escape, it is thought, from the iodine deficient pasture to other areas which are not deficient. "It was observed in Xew Zealand by Hercus and others {263) "that variation in the average amount of iodine in soils containing more than 10 p. p. m. has little effect on the small incidence of goiter which there exists; but as the amount of soil iodine decreases so the incidence striking inverse correlation between the quantity of iodine in the soils and foods and the incidence of goiter was reported by Hercus and coworkers(263) in1931. Their data are given in table7.…”

Miscellaneous Studies on the Iodine and Goitre Problem in New Zealand

“…THE present paper represents a continuation of the researches into the natural sources of iodine in New Zealand which have been carried out in connection with goitre research during recent years at Otago University (see papers by Hercus, Benson and Carter, 1925;Hercus and Roberts, 1927;Hercus, Aitken, Thomson and Cox, 1931). Our recent studies on the occurrence of iodine have to do with the amount and nature of the iodine which is present in rather high concentration in some sea weeds and sea fish, and also with the question of the iodine content of pigs' thyroids, while those on iodine metabolism include an investigation of experimental goitre in rabbits and of the variations in the iodine content of the blood during anaesthesia.…”