A greater dose of a medicine is necessary to reach a given plasma concentration for a substance with a high Vd because such compounds are more likely to leave the plasma and enter the extravascular compartments of the body. More distribution to other tissues is associated with high Vd. On the other hand, a medication with a low Vd has a tendency to stay in the plasma, requiring a lower dosage to reach a given plasma concentration. Less distribution to other tissues when Vd is low. The proper Vd is in the range of 0.04-20 L/kg.