Vitamin B12 is needed to help maintain healthy nerve and red blood cells. MayoClinic.com points out that because the nutrient is naturally found in a wide variety of dietary sources, B12 deficiency is rare. However, the nutritional deficiency occurs in the elderly and other individuals who have a problem absorbing vitamin B12 into the bloodstream. Vegetarians and vegans also are at higher risk. Headaches can be a symptom of B12 deficiency.
Symptoms
Research shows that, in addition to headache, vitamin B12 deficiency can lead to other neurologic symptoms including muscle weakness, spasticity, shakiness, unsteady gait and dementia, according to MayoClinic.com. These symptoms can occur when B12 levels are even slightly lower than normal. Other symptoms of B12 deficiency may include nausea, decreased appetite, diarrhea, lack of energy and fatigue.
Causes
In addition to nutritional deficiency, low stomach acid, which is often the result of inflammation of the acid-secreting cells lining the stomach, is a common cause of vitamin B12 deficiency. Gastritis, pernicious anemia, lack of pancreatic enzymes, peptic ulcers or gastric cancer can each lead to malabsorption problems. Drinking alcohol in excess can also interfere with the absorption of vitamin B12.
Diagnosis
Early diagnosis and treatment can reverse most of the symptoms associated with vitamin B12 deficiency, including headache. While diagnosis is generally based on low serum B12 levels, doctors often look for clinical evidence of the condition. Because older individuals can present with neuropsychiatric symptoms before evidence of the disease shows up in blood tests, diagnosis is not always based on low serum B12 levels alone. The American Academy of Family Physicians points out that studies suggest elevated homocysteine levels may be another early marker for B12 deficiency.
Sources
Vitamin B12 is found in animal foods such as meat, fish, eggs and milk. Some breakfast cereals and other food products are fortified with vitamin B12. Although there are dietary supplements available, most multivitamins that you purchase over-the-counter contain vitamin B12. If you suffer from B12 deficiency, your doctor may order a vitamin B12 shot.
Side Effects
Diarrhea, and rash, itching and redness of the skin are some of the side effects of vitamin B12 supplementation that have been reported. In some cases, treatment of B12 deficiency can lead to peripheral vascular thrombosis. Gout and severe optic nerve atrophy are other possible adverse side effects of vitamin B12 treatment.
Warning
The National Institutes of Health's Office of Dietary Supplements warns that although vitamin B12 is normally safe, certain medications prescribed to treat diabetes, acid reflux and peptic ulcer disease can affect the rate at which the body absorbs this essential nutrient.
