I had a stress frx three months ago that healed and then reinjured by walking. blood tests revealed low wbc and low vitamin d. is leukemia possible?

Seems unlklely: The degree of decrease in the WBC would be of interest. This is a presentation of leukemia, but other things much higher on the list, especially if HGB and PLT normal. Vit d may be related to the stress fracture, but not the change in wbc.

Likely not: Leukemia usually presents with higher than normal white count with other symptoms - fatigue, weakness, night sweats, weight loss, loss of appetite. Check your previous white cell count. If you had a past low white count, then that's your baseline. Don't be alarmed!