To inhale in a dream is to accept outside knowledge. You take in the air which supports life, accepting your reliance upon the network of society which surrounds us all. Deep inhalation breathing is naturally calming; it is used in yoga to become more centered in the present moment. Your subconscious is finding its place in the world.
To inhale something other than air in a dream symbolizes an imbalance and a disconnection from society. You have allowed a single project, emotion, or person to put you off center.