Selenium-toxicosis: the etiologic or causative factor in pellagra?

Conclusions

The present state of knowledge concerning the cause of pellagra is still unsatisfactory.

The rather poor showing of vitamin therapy in pellagra would only point to a cause other than one of a nutritional deficiency.

A striking resemblance is to be noted between the symptoms of pellagra and selenium poisoning, and there is reason to believe this disease is the result of a similar poisoning. The toxic poisoning is absorbed from the food in the alimentary tract and spreads throughout the body, concentrating principally in the liver where it does the greatest damage. That it acts perhaps as an oxydative catalyst by causing the destruction of certain vital food constituents by oxydation, or by preventing the proper absorption, assimilation or utilization by the body of the food in an adequate manner may be possible.

The actinic dermatitis present in these cases, and excited by exposure to sunlight could be due to the fluorescent substance, hematoporphyrin, or some similar-acting photodynamic substance in the blood-stream which is capable of sensitizing the skin to sunlight. This substance is apparently manufactured in the body as the result of the action of the toxic substance (selenium?) on the body sulphur whereby the resultant increased sulphuric acid of the body acts on the hemoglobin forming the photo-sensitizing substance.

As there is a disturbed sulphur metabolism in pellagra, a diet that is rich in sulphur, and the institution of sulphur therapy, would appear to maintain immunity against the disease. If, on the other hand, the body tissues should be so extensively damaged and beyond Nature’s repair, then any food, vitamin, or for that matter, any therapeutic measures would be unlikely to restore structures so injured and would be of no avail.

Chemical examinations and spectroscopic analyses should be made of the foods and soils in pellagrinous districts to determine the presence, and concentration, of any and all toxic substances, that the proper study of toxic limits, tolerance limits, diagnostic symptoms, and remedial measures could be undertaken thus safeguarding the public health within the areas affected.