Serum vitamin B12, serum folate and red blood cell folate levels were examined among 36 strict vegans of 5-35 years' duration.

Vitamin B12 levels among the vegans were generally lower than in a control population. Most of the vegans had vitamin B12 values less than 200 pg/ml. 

None of the vegans had any hematologic evidence of vitamin B12 deficiency, however four of them had neurologic complaints. Long-standing vegans should be monitored for vitamin B12 levels.

Red blood cell folate levels were normal but serum folate levels among the vegans were higher than among the controls.