Methemoglobinemia is unusually frequent in Alaskan Eskimos and Indians in whom 15 confirmed cases in a population of about 20,000 are known. It appears to be due to the absence of a factor in red cells which mediates the reduction of methemoglobin by reduced pyridine nucleotides. This anomaly is probably inherited as a recessive trait.
The amount of methemoglobin present at any one time in these persons is variable, depending on some environmental influence. The evidence suggests that this environmental influence is the dietary intake of ascorbic acid.