While boiled beef is heated throughout, with more or less complete destruction of vitamines, roast beef does not sustain a temperature above 70°C. in its interior, hence the greater portion of the vitamine content is present in such meat.
It is possible that moulds may deprive cereals of their vitamines so that spoiled cereals may be beriberi-producing. There have been many reports both from asylums and prisons which would indicate that the employed and the patients or prisoners lived on the same ration yet the guards or nurses failed to develop beriberi, which disease was prevalent among the inmates. Such statements rarely stand the test of investigation. The same is true of pellagra.
Many of the reported outbreaks of beriberi among those who were enjoying an abundant ration have been found to be connected with the almost exclusive consumption of expensive canned meats and vegetables.
As the beriberi vitamine is apparently important in carbohydrate metabolism, a greater ingestion of carbohydrates demands more vitamine, hence an increase in carbohydrates, without corresponding increase in vitamine-containing foods, may bring on beriberi where, before the increase in carbohydrates, there was an absence of beriberi.
In connection with the development of beriberi it must always be kept in mind that debilitating conditions such as unhygienic quarters and overexertion, as well as disease conditions (malaria, ancylostomiasis, etc.) are factors of importance. In military forces excessive drills should be stopped. The fatigue factor is to be kept in mind in this as in other food deficiency diseases.
A combination of barley, which is rich in vitamines, with the rice is important in oriental countries, thus a diet containing 6 parts barley to 4 parts rice and used in Japanese prisons, on account of its cheapness, not only prevented beriberi but cured the disease in beriberics entering prison.
There is no doubt but that legislation against rice which contains less than 0.4% of P2O5 is a valuable measure of prophylaxis. Polished rice has lost in P2O5 as well as in vitamines.
Heiser has proposed that an excessive tax be placed on polished rice with free entry for the unpolished article. The following suggestions of Vedder in connection with prophylaxis would seem to be worthy of consideration in pellagra as well as in beriberi.
1. In any institution where bread is the staple article of diet, it should be made from whole wheat flour.