Numbness of the tongue, in addition to tingling, results from consuming certain medications, substances or toxins; trauma or injury to the tongue; or imbalanced vitamins and minerals. Numbness and tingling can occur as a result of damage to the nervous system.
The ingestion of certain substances such as some alcohols, medications and narcotics can cause numbness of the tongue with only a short-term effect, explains HealthHype.com. Anesthesia used in dental practices cause this sensation, too.
In the case of tongue injury, numbness sometimes presents along with pain, and can result from burning the tongue, biting it or consuming a large amount of acidic or alkaline foods. An excess of calcium, sodium or potassium, or a deficiency of vitamin B12 sometimes causes tongue numbness, notes HealthHype.com.