Fatigue is the most common symptom of people who have low levels of Vitamin B12.
Other signs of B12 deficiency : weight loss, constipation or diarrhea, vomiting, abdominal bloating, gas, numbness or tingling of the hands and feet, loss of balance and a sore or red tongue.
B12 deficiency may happen when you are not getting the right nutrients in your diet, when your body can’t absorb nutrients properly and when you have other problems in the digestive system.
Since most B12 comes from animal products, vegans are at risk for B12 deficiency. Crohn’s and celiac disease, weight loss surgery and chronic alcoholism can interfere with the ability to absorb enough of it.
Vitamin B12 is a critical nutrient that helps your body make healthy red blood cells. A chronic lack of B12 can lead to anemia.