Vitamins in rat's and in guinea-pig's milk

Abstract
The following values were obtained by physical and chemical methods for the conc. per 100 ml. of vit. A, carotene, vit. B1, riboflavin and vit. C respectively in rat''s and guinea-pig''s milks, viz. rat: 0.13 mg.; not measurable; 50-80 I.U.; 0.4-0.8 mg.; 0.4 mg.; guinea-pig: 0.09 mg.; 0.011 mg.; 20 I.U.; 0.085 mg.; 29.0 mg. Compared with cow''s milk rat''s milk is richer in vit. B1 and riboflavin but contains much less vit. C. Guinea-pig''s milk on the contrary contains relatively enormous quantities of vit. C, about half the amt. present in an avg. lemon juice. Feeding large quantities of riboflavin to lactating rats definitely increased the conc. of this factor in milk but generous adm. of vit. C and of vit. B1 was without effect. On the other hand the vit. B1 content of rat''s milk dropped sharply when a vit. B1-deficient diet was fed.