Allow the grits to settle a full minute, tilt the pan, and skim off and discard the chaff and hulls with a fine tea strainer. Cook the grits for 50 minutes if the grits were soaked overnight or else 90 minutes if not." Most of the niacin in mature cereal grains is present as niacytin, which is niacin bound up in a complex with hemicellulose which is nutritionally unavailable. In mature corn this may be up to 90% of the total niacin content. The preparation method of nixtamalization using the whole dried corn kernel made this niacin nutritionally available and reduced the chance of developing pellagra. Niacytin is concentrated in the aleurone and germ layers which are removed by milling. The milling and degerming of corn in the preparation of cornmeal became feasible with the development of the Beall degerminator, which was originally patented in 1901 and was used to separate the grit from the germ in corn processing. However, this process of degermination reduces the niacin content of the cornmeal. Casimir Funk, who helped elucidate the role of thiamin in the etiology of beriberi, was an early investigator of the problem of pellagra. Funk suggested that a change in the method of milling corn was responsible for the outbreak of pellagra, but no attention was paid to his article on this subject.Pellagra developed especially among the vulnerable populations in institutions such as orphanages and prisons, because of the monotonous and restricted diet.
If maize is not nixtamalized, it is a poor source of tryptophan, as well as niacin. Nixtamalization corrects the niacin deficiency, and is a common practice in Native American cultures that grow corn, but most especially in Mexico and the countries of Central America. Following the corn cycle, the symptoms usually appear during spring, increase in the summer due to greater sun exposure, and return the following spring. Indeed, pellagra was once endemic in the poorer states of the U.S. South, such as Mississippi and Alabama, where its cyclical appearance in the spring after meat-heavy winter diets led to it being known as "spring sickness" (particularly when it appeared among more vulnerable children), as well as among the residents of jails and orphanages as studied by Dr. Joseph Goldberger.Pellagra is common in Africa, Indonesia, and China. In affluent societies, a majority of patients with clinical pellagra are poor, homeless, alcohol-dependent, or psychiatric patients who refuse food. Pellagra was common among prisoners of Soviet labor camps (the Gulags). In addition, pellagra, as a micronutrient deficiency disease, frequently affects populations of refugees and other displaced people due to their unique, long-term residential circumstances and dependence on food aid. Refugees typically rely on limited sources of niacin provided to them, often peanuts (which, in Africa, may be supplied in place of local groundnut staples, such as the Bambara or Hausa groundnut); the instability in the nutritional content and distribution of food aid can be the cause of pellagra in displaced populations.