Studies on the occurrence of what has hitherto been called vitamin B have shown that this food factor is widely distributed in nature. It is found in most common foods of both plant and animal origin (Osborne and Mendel,1 Sherman and Smith,2 McCollum and Simmonds3 and Sherman4). Its distribution in animal tissues was investigated by Cooper,5 who used the pigeon method and found that the liver and cardiac muscle of the ox were good sources of the antineuritic, water-soluble vitamin. Similarly, Osborne and Mendel,5 using the growth of rats as the criterion for the presence of the water-soluble B-vitamin, reported that such tissues as the heart, liver, brain and kidney of the pig were rich in this food factor.
The presence of vitamin B in hormone preparations, however, is not so well known. A review of the literature revealed a paucity of such observations. Eddy7 demonstrated the presence of vitamin