Experimental Study of Clinical Vitamin B Deficiency.

Clinical disturbances incident to mild deficiency of vitamin B 2 in the diet, as opposed to frank deficiencies such as beriberi and pellagra, are commonly believed to be very rare in man and are thought to occur only when the diet is grossly abnormal or when there is serious interference with absorption from the gastro-intestinal tract. Certain observations made in this Gastro-Intestinal Section, however, have suggested that clinical evidences of such partial deficiency may develop on given for the first five months a diet moderately deficient in vitamin B though adequate in every other known requirement and the effects of this diet were studied. When clinical signs suggestive of deficiency were manifest, various vitamin B fractions were added to the diet, in series, and the effects of their administration studied. The second patient (Case 2), who entered the hospital with fully developed clinical evidence of deficiency, was likewise placed on a diet restricted in