Hyperthyroidism and Vitamin C ∗

Abstract

Recently this laboratory has demonstrated that crystalline vitamin B₁, when administered in large doses will prevent the rapid tissue catabolism and even permit considerable growth in hyperthyroidism in the rat, provided the diet was fortified with an abundance of the stable factor of the vitamin B complex. 1

During the past 18 months we have been investigating oxidation-reduction efficiency in avitaminosis, which included studies of ascorbic acid concentration in blood, tissues, and endocrine glands. Although it is claimed that the rat either synthesizes vitamin C or requires such minimum amounts that are undetectable by available micro-methods, we are finding appreciable reduction of this vitamin in certain tissues in vitamin B₁ deficiency, thus establishing a definite vitamin interrelationship.

In continuing with the problem of the antithyrogenic action of vitamin B₁ and the possible supplementary value of riboflavin to a ration supplying the stable components of the vitamin B complex in the form of autoclaved beef, it was thought of interest to determine the influence of hyperthyroidism on the ascorbic acid or vitamin C† content of various tissues and endocrines. The experiments were carried out in two series: (1) Five sets in groups of 3 and (2) four sets in groups of 4. The animals were 34 to 53 days of age, ranging in weight from 65 to 101 gm. at the beginning of the experiments. The daily dose of 1-thyroxine (Squibbs) was 0.1 mg. and the number of days on thyroxine varied from 10 to 16 days.

The technique employed was that described in a recent communication.' As a source of the B vitamins, we used in 4 series of experiments, 500 mg. Northwestern yeast; in three, 4@ to 6Oy crystal-line vitamin B, (Betaxin); and in two, lOq. vitamin B1 plus 4Or riboflavin. We found that crystalline vitamin B1 may approximate the protective action of dried Northwestern yeast in hyperthyroidism, from the standpoint of permitting increases in weight in presence of toxic doses of thyroxine, provided enough riboflavin is furnished daily as a supplement to our Ration 2345.'