I have deficiency in vitamin d and vitamin b-12....What should I do to cure this problem?

Replacement would be. Appropriate for d and b12. Problem with B12 is one of absorption and oral may not be the answer. Talk to your doc.
Check out why... Vitamin d deficiency is common, and can be treated easily with 2000 units of vitamin d3/day. B-12 deficiency is less common and needs a medical work-up to make sure it's real and try to discover the cause. If necessary, it can also be replaced but is slightly more involved that vitamin d replacement.