The following ocular changes were observed in the rabbit in niacin deficiency.
(1) Increase, separation, and movement of the pigment at the limbi corneae. (2) Reactive congestion at the limbi corneae and a little corneal vascularization. (3) Separation and movement to rod and cone layer of the pigment at the pigment epithelium. (4) Slight degeneration in the ganglion cells in the retina. Various ocular changes resembling those observed in “Shibi-Gattchaki” patients as well as pellagrins have been produced in niacin deficiency of the rabbit. Further, the following relations between riboflavin and niacin were observed in riboflavin plus niacin-deficient rabbits.
(1) In the riboflavin-deficient animals, urinary riboflavin was far less than that of the control animals: urinary riboflavin excretion in the load test was markedly less, indicating a low riboflavin saturation, and the riboflavin levels in the viscera (liver, kidneys, lungs, and heart) were lower than those in the control animals whether riboflavin had been loaded or not.
(2) In the niacin-deficient animals, urinary niacin decreased more remarkably than in the control animals, and in the niacin plus riboflavin-deficient animals, urinary niacin fell slightly more than in the niacin-deficient animals. By tryptophan administration, urinary niacin rose temporarily and then fell rapidly till finally disappeared The niacin levels in the viscera of these deficient animals were lower than those in the control animals.
(3) Niacin content of the viscera in the niacin plus riboflavin-deficient animals showed seemingly a tendency to decrease more than that in the niacin-deficient animals
(4) In the niacin-deficient animals, the riboflavin levels in the viscera were always lower than those in the control animals, whether riboflavin had been loaded or not. From these results it is assumed that niacin and riboflavin compensate for each other, performing synergetic actions in consuming the vitamins in vivo. There may be some other inseparable relationships between the two vitamins, since riboflavin deficiency brought about niacin deficiency.

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Although the detection of Dragendorff-positive spot on paper chromatogram due to the pyrimidine compound formed from thiamine by bacterial thiaminase I had failed thus far, it was shown in the present experiment that the crude crystalline pyrimidine compound (Pm-X⋅HCl) isolated from the thiamine reaction products by the bacterial thiaminase I gave a Dragendorff-positive spot at R_F 0.06 in contrast with R_F 0.59 of thiamine, when n-butanol methanol-water (4:2:2) was used as the solvent system for the development of paper chromatography.
The absorption maximum of Pm-X·HCl extracted by 0.001N hydrochloric acid from a paper strip around R_F 0.06 of the paper chromatogram was found at 250mμ, and the form of the absorption spectrum of the substance differed somewhat from that of thiamine when measured at the same pH.
Pm-X was found to promote the growth of BKA, similarly to thiamine as well as other pyrimidine compounds having an amino group on the C₄-position of pyrimidine. These findings have led to the conclusion that the isolated pyrimidine compound consisted certainly of the pyrimidine moiety of thiamine and possibly of a base, the nature of which remains to be settled.

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In experiments in human subject, it was found that there was a decrease in synthesis of riboflavin by intestinal bacteria when the diet was changed from an ordinary to a meat diet but with addition of cellulose, there was an increase in the synthesis of the vitamin.
When cellulose was added to a vegetable diet, the effect became even more marked. For increase in riboflavin content of the urine, the addition of meat besides cellulose had a greater effct.

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In studies in man, it was found that a switch from an ordinary to a meat diet resulted in a reduction in the synthesis of thiamine by intestinal bacteria but with the addition of cellulose, there was an increase. This effect was likewise pronounced when cellulose was added to a vegetable diet. For increasing thiamine in the urine, the supplementation of meat in addition to cellulose seems to be beneficial.

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1. The effect of Chl on the biological activity of vitamin C was tested using guinea pigs and it was proved that the animals receiving 0.5mg ascorbic acid (minimum requirement) together with 1mg Chl, showed the effect corresponding to those receiving 1mg ascorbic acid alone.
2. Administration of Chl alone even in a large amount could never prevent vitamin C deficiency.
3. When vitamin C is administered as natural vegetables, the effect of Chl plus vitamin C (green leaves) proved to be more effective in gaining body weight than that of the vitamin alone (bean sprouts).

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The absorbability of β-carotene was studied in an adult, Japanese female under various conditions and with various kinds of food. The following values, in per cent, were obtained: pure carotene suspension, ca. 60; oil solution of pure carotene, 98; carrots cooked in the ordinary manner, 21; pumpkin, 35-53; and spinach, 33-35.
There is some increase in the absorbability with the addition of margarine or olive oil but under the conditions of the experiments, the increase was insignificant.
Supplementation of vitamin B₁₂ or tocopherol resulted in some increase but the difference was not marked. The absorption with dried seaweed was 8 per cent and in the case of shellfish (Tapes philippinarum) there was scarcely any absorption. It is suggested that the seaweed and shellfish are poor sources of carotene.

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A procedure for converting thiamine in tissue slices into thiochrome and for applying the fluorescence to histochemical study was described and the various conditions were examined. The thiamine distribution pictures obtained by this procedure in various cells, tissues and organs are described in detail.

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1. A microscopic survey was carried out on the morphology of tissues and the existing state of fat substances in several kinds of fish containing much vitamin A.
2. The lean tissue consists of compact protein substances in which micro-particles of lipoids are dispersed, but the fatty tissue is composed of lattice fibres consisting of coarse protein substances, among the lattice fibres of which a good deal of oil is contained.
3. The differences of the amount of vitamin A per g of tissue of several kinds of fish and organs are less than those of the amount of vitamin A per g of oil.
4. It was elucidated that vitamin A co-existed opulently with fat component in micro-particles in the mucous membrane of pyloric caeca of the oil sole as seen in frozen sections stained by the osmium-GDH method.
5. It was found that vitamin A existed in association with melanin pigments which are dispersed in liver tissues of the dog fish and other sharks, as can be demonstrated when their frozen sections are stained with osmium-GDH reagents after moderate defatting with absolute alcohol.

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1. Experimental folic acid deficiency was induced in man by administration of aminopterin.
2. Changes in the digestive, cardiovascular, and genital systems were observed.
3. These changes generally responded to PGA treatment rapidly.

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The changes occurring in the blood picture following prolonged administration of aminopterin in healthy human subjects were described. A close relationship was revealed between these changes and the folic acid level in blood.

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