If i have had very low levels of vitamin d for a while and i am taking a d supplement, should i add calcium supplement as well?

Little. Key: get D3: ↑↑ enough. D3 is essential for absorption of Ca+2, from food, supplement pills poorly absorbed. Desirable D3 conc. 70-80 ng/ml; generally wait ~3 months between checks. Reasonable replacement doses ~35,000 to 60,000 IU per week. Most OTC D3 supplements, in my experience, not very effective; search for a quality preparation. A common source is lanolin from sheep raised for their wool.