A disturbance of the calcium balance has been found in thyroid disease.1 Apparently there is a relationship between the calcium and Iodine intake, the normal function of the thyroid gland and the development of goiter.2 Consequently, we became interested in determining any existing correlation between the total calcium and Iodine metabolism and thyroid disease in man. For at least a century calcium has been considered a factor in the production of goiter. As early as 1837 McClelland3 reported this belief. The Iodine deficiency theory of goiter, which has been accepted by many, was advocated by Maffoni4 in 1846, by Prevost5 in 1849 and by Chatin6 in 1852.