I m 20 yr old and from india. can deficiency of vitamin b12 & d3 cause seizures? and how to treat with deficiency of vitamins?

No: It is extremely unlikely that you could type a question or navigate an internet medicine app if you had B12 deficiency severe enough to provoke seizures. B12 supplementation is easy--eat animal protein at least once a day, or take a multivitamin daily. The multivitamin would also likely meet your vit d daily requirement; if not, work with your doctor to correct this deficiency. Good luck!

Fix all issues: Seizure meds can interfere with vit d (and folate) metabolism. Seizures can come from many causes and are often easy to control with meds. You definately want to 'dial in' good numbers on the B12 and vit d and keep your serum level of B12 above 350 and the vit d 25-oh level above 30 and below 100.