Abstract and Introduction
Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is important in the hematological and nervous systems, and it has a complex relationship with the skin. Altered cobalamin levels can lead to dermatological manifestations, which may indicate a deficiency or excess of this vitamin. The biochemistry and metabolism of cobalamin is complex, and diseases can be associated with alterations of this metabolic pathway. The cutaneous manifestations of cobalamin deficiency include hyperpigmentation (most commonly); hair and nail changes; and oral changes, including glossitis. Additionally, several dermatologic conditions, including vitiligo, aphthous stomatitis, atopic dermatitis, and acne are related to cobalamin excess or deficiency. The cutaneous complications of cobalamin therapy include acne, rosacea, and allergic site reactions, or anaphylaxis with cobalamin injections. As cobalt is a component of cobalamin, patients with cobalt sensitivity have been reported to have cutaneous manifestations when receiving cobalamin replacement therapy.
Vitamin B12, also known as cobalamin, is a water-soluble vitamin that is very important in the hematological and nervous systems. It exists in many forms in the body, and is a cofactor for homocysteine methyltransferase and methylmalonyl-CoA mutase. The primary source for cobalamin is animal products, as it is synthesized by microorganisms such as bacteria. This paper reviews the metabolism of cobalamin, diseases associated with an elevated cobalamin level, the clinical manifestations of cobalamin deficiency, several dermatologic conditions (vitiligo, aphthous stomatitis, atopic dermatitis) and their relationships to cobalamin, and complications of cobalamin therapy. The focus is on the disease states and findings that are significant to the dermatologist, in an effort to increase awareness of the various manners in which cobalamin alterations can influence the diagnosis and treatment of several diseases.
Am J Clin Dermatol. 2015;16(1):27-33. © 2015 Adis Springer International Publishing AG