Vitamin B-12, one of the many nutrients the body needs to function properly, is critical for the formation of red blood cells, metabolism and DNA synthesis. Vitamin B-12 is naturally present in some foods, added to some foods during manufacturing, used in different forms as treatment for medical conditions and taken as a dietary supplement. A vitamin B-12 deficiency can cause serious medical conditions, such as a form of anemia and neurological changes. Recent studies suggest a connection between low levels of vitamin B-12 and a form of urticaria for which a cause has not yet been identified.
Chronic Idiopathic Urticaria
Urticaria, or hives, usually occurs as an allergic reaction to medicine or food. Hives are red, raised, itchy welts that appear on the skin. Chronic idiopathic urticaria, or CIU, is a form of the condition that lasts for six weeks or more, causes daily itching and appears to have no cause. The condition is triggered when the release of chemicals, including histamines, into the bloodstream by mast cells causes leakage in small blood vessels. Chronic urticaria might be caused by an autoimmune condition, according to Mayo Clinic.
B-12 and CIU Study
A study begun in 2002 by N. Mete and five other researchers at the Ege University Medical School in Turkey, and published in 2004 in the "Journal of Investigational Allergology and Clinical Immunology," evaluated the vitamin B-12 serum levels of healthy participants and participants diagnosed with chronic urticaria. The study found that 33 percent of the participants with CIU had serum levels of B-12 that were below the normal range. These participants also had higher levels of the autoantibodies that cause wheals, the raised bumps characteristic of urticaria. Healthy participants did not have low B-12 levels.
While a deficiency in B-12 occurs nine times as often in people with certain autoimmune disorders than in people without such disorders, the prevalence of B-12 deficiency in people with CIU over the normal population is unknown, according to the Mete study. The Mete study found no clinical evidence of B-12 deficiency in the patients who had low levels of B-12. Studies report that H. pylori bacterial infections can cause vitamin B-12 deficiency and, although there is no proof that H. pylori causes chronic urticaria, the Mete study notes increasing reports of H. pylori and CIU appearing together.
While researchers search for the cause of chronic urticaria, treatment of the condition remains a challenge, as the triggers for the allergic reaction are unknown. Treatment of CIU usually involves treating the symptoms with medications. Oral antihistamines block the release of the histamine that causes the hives. Patients use different medications, or combinations of medications, to find a treatment that works for them. Medications for patients who do not find relief from oral antihistamines include oral corticosteroids, H-2 antagonists and tricyclic antidepressants, which have the properties of oral antihistamines.