Observations on the Serum Calcium, Proteins, and Inorganic Phosphorus in Experimental Vitamin B Deficiency and Inanition.*

In recent experimental vitamin B deficiency studies the usual practice now is to provide the test animals with a complete diet containing all essentials in proper proportion, omitting only the factor under investigation. Such a program is especially valuable for physiological experiments. Agreement in the observations on different species of animals can only be expected when the nutritional conditions are equivalent. Many controversies are found in the earlier literature on experimental vitamin B deficiency due probably to the disregard of an incomplete diet and the abstinence of food which animals on a vitamin B-free diet frequently exhibit, Thus the convulsions and, in the most typical cases, the head retraction of pigeons fed on a polished rice diet have been considered the most characteristic symptoms of the vitamin B deficiency. Since this state is also obtained by prolonged fasting, a more exhaustive investigation seemed essential to determine the vitamin B deficiency effect. McCarrison (12), Drummond (4), Kon and Drummond (S), and many others have studied extensively the different factors collectively responsible for what is called a vitamin B-deficient state. Today we fortunately have very good combinations of diets for the three species of animals most used in these experiments, namely the pigeon, the rat, and the dog. In regard to the blood calcium level in experimental B avitaminosis, two different findings are reported. Ungar (20), working on pigeons, assumed a relation between the convulsions and the blood calcium level. Upon determination the serum calcium was found