I have a deficiency of vitamin d, what should i do?

Supplement D3, D2, D: Desirable concentrations of d3 (the one which counts, not d or d2) are in the 70-80 range. Search for a supplement which provides enough to raise concentrations, many otc &rx are not effective. Ones made from lanolin of sheep grown for their wool often work well, reasonable doses are often in the 25, 000 to 50, 000 iu/wk, often upper end. Allow ~3 months to check efficacy.