Studies on the Blood Pyridoxine of Vitamin B 6 Deficient Monkeys. *

Summary

Suitable modifications for the extraction and assay of blood pyridoxine are described. The vitamin B₆ levels of 14 rhesus monkeys were followed before and after withdrawal of the vitamin from the diet. The vitamin B₆ levels fell during the first 2 weeks of deprivation. This usually brought the levels down to values of 2-3 μg per 100 ml of whole blood or lower, where they remained throughout the rest of the experiment for periods exceeding 1 year. Control animals on a daily intake of equivalent to 1 mg of pyridoxine hydrochloric acid had values ranging horn 5.0 to 20.8 μg, averaging 11.2. Some of the changes observed in deficient animals are discussed.