_Food Deficiency._—Before taking up the better known considerations noted above it may be stated that many now believe that pellagra, along with beriberi and scurvy, belongs to the group of “food deficiency” diseases. Just as beriberi is caused by the absence of a neuritis-preventing substance or vitamine in the dietary, so is the symptom-complex of pellagra brought about by the absence from the dietary of some vitamine or vitamines essential to proper metabolism. There are various ideas as to the factor which eliminates the pellagra-preventing vitamines. Some claim that in the process of milling maize the vitamine-containing outer portion (bran) has been taken off just as with beriberi-producing white rice, from which the pericarp with its neuritis-preventing vitamine has been more or less completely removed. From analyses of milled maize and millings Funk has recently suggested that pellagra in different countries is in relation to the degree of milling. Just as with rice and maize so does excessive milling of wheat get rid of vitamines, therefore, bread made from highly milled flour is dietetically deficient. Again, as brought out by Voegtlin, alkalis tend to destroy any remaining vitamines in such bread. The practice of using sodium bicarbonate in preparation of bread is a further factor in the food deficiency problem. With the use of baking powder or buttermilk the alkaline carbonate of soda is neutralized so that there is no destructive effect on vitamine content. The vitamine deficiency of highly milled flour and highly milled corn meal runs parallel with the phosphorus pentoxide content of such products. Whole wheat shows about 1.1% P_{2}O_{5}, while highly milled flour contains only about 0.1%. Whole corn has about 0.76% P_{2}O_{5}, while milled corn meal has only about 0.3%. Highly milled rice has under 0.4% P_{2}O_{5}. Others think that as the result of bacterial or mould diseases of the corn grain these important vitamines are destroyed. Then too, as with rice and beriberi, the prevailing idea is that while there is a striking association between a maize dietary deficient in the pellagra-preventing vitamine and the occurrence of pellagra, yet this deficiency may be supplied by other foods. Beriberi seems rather definitely to be associated with a deficiency in the anti-neuritis vitamine, which is probably the same as water soluble B., and in pellagra-producing diets a similar deficiency may be noted. More striking however is the deficiency in fat soluble A in such diets. This vitamine is abundant in butter fat and egg yolk, articles of diet of which pellagrins are deprived.