Vitamin B-12 is one of eight B vitamins essential for your body. Your body requires B-12 for energy, DNA production, red blood cell formation and maintenance of the nervous system. Since your body does not create B-12, you must consume foods rich in the vitamin such as fish, milk products, poultry and meats. Viitamin B-12 can be stored in the liver for up to five years so often when symptoms begin it has progressed to a condition known as vitamin B-12 deficiency anemia, a condition in which your body does not produce enough healthy red blood cells.
Fatigue
Red blood cells contain a protein known as hemoglobin which carries oxygen to all the cells in your body. When you have vitamin B-12 deficiency anemia, it can cause an oxygen deficit. Without oxygen to carry out all the necessary tasks, the body will reroute oxygen to the most vital functions such as maintaining oxygenation of the heart, lungs and brain. This can lead to fatigue and weakness.
Another cause for fatigue in vitamin B-12 deficiency involves energy creation. Vitamin B-12, as well as other B vitamins, are necessary for the breakdown of carbohydrates, fats and protein for energy, according to the National Institutes of Health. A lack of B-12 will cause an inability to properly convert food to energy, causing fatigue.
Shortness of Breath
Just as a lack of red blood cells can cause fatigue, it can also cause shortness of breath. As the body depletes itself of red blood cells, less oxygen circulates throughout the body. The National Institutes of Health explains that people will often first notice shortness of breath upon exertion, such as when exercising or walking up a flight of stairs. Over time, this can worsen, causing dizziness and lightheadedness.
Numbness and Tingling
Vitamin B-12 is essential for maintaining the health of the nervous system. B-12 deficiency anemia can lead to a condition known as peripheral neuropathy. The peripheral nerves carry messages from your brain and spinal cord to the tissues, organs and skin. Over time, a B-12 deficiency can damage and even destroy nerve cells. Symptoms often show up in the longest nerves, such as the nerves of the toes first. The initial symptoms often damage the sensory nerves first causing pain, tingling and numbness in the extremities. If treatment is administered within the six months of initial treatments, symptoms may reverse themselves.
