The Blood Picture of Pyridoxine Deficiency in the Monkey

1. Pyridoxine deficiency in the monkey results in a severe anemia characterized by hypochromia, increase in mean diameter, decrease in mean cell thickness, dehydration, the appearance of "target" cells and increased resistance to hemolysis.

2. The administration of pyridoxine results in restoration of hematologic values to normal, correction of dehydration and disappearance of "target" cells.

3. Further evidence is offered relating "target" cells to dehydration and, in addition, possibly to hepatic damage.

4. A delayed macrocytic anemia which was not corrected by low doses of vitamin B₁₂, folic acid or iron is described in control animals. This anemia occurred chronologically one to two years later than the induced anemia of pyridoxine deficiency and is not necessarily related. The cause of this anemia is unknown.

5. Normal hematologic data on twenty-one M. rhesus monkeys is presented.