A 28-year-old unmarried girl reported with prolonged menstrual cycle, her height is5'.7", body weight 72 kgs. She gained 3 kg weight in last three months. She brought reports of CBC, blood sugar random, LFT, KFT, lipid profile, hormones including thyroid profile, FSH, LH, prolactin.

All reports were normal except prolactin174 and vitamin D deficiency. What further investigation and line of action is needed in this case? Please give your expert advice.