A healthy human tongue appears bumpy and pink in color. It's possible to have a smooth tongue, however, when your health begins to decline. You can get a smooth tongue from a vitamin B12 deficiency or anemia. If you notice that your tongue has gotten smooth, speak to a doctor so that the underlying cause can be addressed.
Acquire a vitamin B12 deficiency by drinking alcohol on a regular basis, or suffering from alcoholism. Too much alcohol consumption will lower B12 levels in your body, leading to a deficiency of the vitamin.
Refuse to eat foods that contain healthy amounts of vitamin B12, such as beef, chicken, fish and eggs, and a variety of milk products.
Suffer from a medical condition, such as Crohn's disease, celiac disease or anemia, that prevents the absorption of vitamins and minerals into your body. When you have one of these conditions, you can eat foods rich in vitamin B12 but still not absorb the amount your body needs.
Consume antacid medicine for an extended period of time. Doing so can lead to a decrease in your body's vitamin B12 levels, resulting in a smooth tongue.