Can Vitamin B12/D3deficiency or Homocystein imbalance cause lack of interest and poor concentration?

Can Vitamin B12/D3 deficiency or Homocystein imbalance fatigue (abnormal high) cause lack of interest and poor concentration? I am experiencing these symptoms recently and not sure whether it is the case had lab tests done and results show deficiency.

Age: 36
Male
Medications: NA