Signs of deficiency, including cutaneous alterations, occur in rats and chicks which are fed purified diets low in the vitamin B complex and supplemented with the synthetic forms of thiamine, riboflavin, nicotinic acid and pyridoxine (vitamin B6). If whole liver or yeast is substituted for the four vitamins there are no signs of deficiency. Therefore there are additional members of the vitamin B complex in the natural foodstuffs. One of these has been identified as pantothenic acid.
Fractionation of "water-soluble vitamin B" was originally accomplished by autoclaving whole yeast.1 By this procedure the antineuritic fraction, vitamin B1 (thiamine), was destroyed, but the growth-promoting, "antidermatitic," heat-stable fraction, vitamin B2 (vitamin G), was unaffected. Later other methods of separation were introduced. Biologically active fractions were obtained in crude adsorbates, eluates and precipitates which were prepared from aqueous extracts of foods rich in the complex. Treatment of whole liver