March 31, 2018

What Do Vitamin B12 Supplementation and Cobalt Allergy Have in Common?

Vitamin B12 supplementation has been linked to the development of an itchy, blistering skin rash, known as contact dermatitis. Specialists distinguish two types of contact dermatitis: irritant and allergic. However, it’s often difficult (and not important) to make a distinction between the two.


While all ages can be affected by contact dermatitis, teenagers and middle-aged adults seem more likely to develop this skin rash. Besides, female population tends to be more commonly affected by contact dermatitis than males.

Contact dermatitis occurs when the skin gets into direct contact with an irritant or allergenic substance. For instance, people allergic to cobalt develop the symptoms of contact dermatitis after exposure to cobalt-containing items. Since vitamin B12 contains a cobalt atom, there has been a link between vitamin B12 supplements and cobalt allergy-related contact dermatitis.

Why Does Vitamin B12 Deficiency Occur?


Vitamin B12 is a water-soluble vitamin naturally found in some foods. This vitamin is essential for the formation of blood cells, as well as for the normal function of your body’s nervous system. Also known as cobalamin, vitamin B12 is available from dietary supplements and is contain in most multi-vitamins.

The absorption of vitamin B12 in your body includes various steps, which makes the process quite complicated. Besides, during each of these step, some kind of defect can occur leading to poor absorption of the vitamin in the small intestine. This may result in vitamin B12 deficiency in certain individuals. In this case, vitamin B12 supplementation may be required.

Some people may take dietary supplements with vitamin B12 and other vitamins from the B group in order to improve their health.

The cobalamin molecule contains a cobalt atom, which means that large amounts of vitamin B12 in the body may cause contact dermatitis in those with a history of cobalt allergy. While in most cases, the symptoms are not severe, they can result in significant discomfort.

If you are allergic to cobalt and also diagnosed with vitamin B12 deficiency, you have to be careful with supplements containing vitamin B12 and maintain adequate levels of the vitamin in the blood.

How to Diagnose a Cobalt Allergy?


People who develop an itchy rash when taking vitamin B12 supplements should consider checking with an allergist. In some cases, such a symptom may indicate that you have an allergy to cobalt. The rash associated with a cobalt allergy often has small blisters full of clear fluid. Sometimes, these blisters can crust, swell, ooze or peel.

In order to confirm a cobalt allergy, many allergists use a patch test method, which is different from skin prick testing. In this test, small amount of cobalt allergy is placed on the skin for a period of 48 hours. At 48 hours after placement, an allergist checks the first results of the test. The repeated interpretation of the results occurs after 72 or 96 hours of placement.

If you develop redness, blister, itching and mild swelling at the site of your skin where a certain chemical was placed, you are likely to be allergic to it. The reaction is normally limited to the affected site of the skin only.

The only patch test for contact dermatitis that is approved by the U.S. Food and Drug Administration is called the TRUE test. However, some specialists order additional chemicals from Europe or Canada to create extended version of allergy patch test panels.

How to Treat a Cobalt Allergy?


You can reduce the rash caused by cobalt allergy or contact dermatitis using topical or systemic corticosteroids. There are both oral and injectable systemic corticosteroids. Yet, the best way to treat allergy to cobalt is to avoid large doses of vitamin B12.

If you have a vitamin B12 deficiency, experts suggest that you keep your vitamin B12 supplementation at a minimum, just to maintain normal levels of the vitamin in your blood.

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