Cobalt Allergy: What is It and What Must Be Avoided?

Cobalt is a metal commonly found in soil, seawater, and various industrial compounds. It is typically found in combination with another metal, nickel, as separating the two metals is too costly. Cobalt is needed for the health of ruminant animals, such as cows and sheep. When these animals consume cobalt, bacteria in their stomachs transform cobalt into cobalamin— more commonly known as vitamin B12—which is needed by all animals and humans. Some people, however, develop an allergy to cobalt, requiring them to avoid certain items and foods. Today, we’re going to discuss cobalt allergy and what you should do if you suspect you have it.

What are the symptoms of cobalt allergy?

Symptoms of an allergic reaction to cobalt may include:

Diagnosing a cobalt allergy can be a bit tricky due to its association with nickel. Cobalt allergy often coexists with nickel allergy in many people, increasing the severity of symptoms. One study found that nickel-sensitive patients with dyshidrotic eczema simultaneously developed a cobalt allergy and patients with simultaneous nickel and cobalt allergies had more severe dyshidrotic eczema.

A cobalt allergy is typically diagnosed by conducting a thorough medical evaluation, studying the patient’s history, and conducting a patch test. Patch testing involves applying a patch containing the test substance (in this case, 2% cobalt chloride) to the patient’s back. Because the reaction takes two or three days to become visible, the patch is left in place for up to 72 hours. Based on the skin’s response to the patch, a cobalt allergy is either confirmed or ruled out. Because cobalt and nickel allergy are so closely related, a patient should always be patch tested for nickel as well, although pure nickel and cobalt test solutions are difficult to obtain.

How is a cobalt allergy treated?

If you’ve been diagnosed with a cobalt allergy or instructed to avoid cobalt by a healthcare professional, treatment consists of avoiding all contact with items containing cobalt. In some people, they need to take it one step further by avoiding oral ingestion of cobalt by eliminating certain foods.

Non-food sources of cobalt

Cobalt is a commonly used metal and, as such, is present in many different non-food items including:

  • colored glass, porcelain, ceramics, pottery, and enamels
  • green and blue watercolors and crayons
  • metal-plated objects, including buckles, buttons, zippers, snaps, utensils and tools
  • metal prostheses
  • dental plates
  • hair dyes
  • antiperspirants
  • certain paints and varnishes
  • rarely, vitamin B12 preparations

Food sources of cobalt

The top three cobalt-containing food groups in the human diet are:

  • Milk, dairy products and chocolate, which account for about 32% of total cobalt intake.
  • Fish and shellfish, which account for about 20%.
  • Condiments, sugar and oils, which account for about 16%.

Other foods you should avoid on a low-cobalt diet include:

  • Apricots
  • Beans
  • Beer
  • Beets
  • Cabbage
  • Cloves
  • Cocoa
  • Coffee
  • Liver
  • Nuts
  • Scallops
  • Tea
  • Whole grain flour

Please note that the above list is not complete. For a more detailed list of foods to eliminate or reduce on a low-cobalt diet, click here. you will have to avoid these foods for at least six weeks to see if this makes a difference in your symptoms. During this time, you should also continue to avoid objects that may potentially contain cobalt. 

Other names for cobalt

When avoiding sources of cobalt, be sure to read labels and avoid any products that contain the following names, as they are alternative names for cobalt:

  • Cobalt dichloride, hexahydrate
  • Cobalt (II) chloride-hexahydrate
  • Cobalt blue
  • Cobaltous chloride hexahydrate

Take it one step at a time

If a low-cobalt diet resolves your symptoms, you can reintroduce foods one by one (one per week) to see how you react to them. Some people don’t react to all the foods listed above, only some of them. By slowly adding the foods back in, you can pinpoint which ones are your
personal triggers.

What’s next?

You might already know that cobalt is affecting your health in some way. Or it’s something you’ll realize when we do an initial assessment. Either way, when we collaborate on a Mineral- Nutritional Balancing Program one of the goals is to strengthen gut health. You might need to limit high-cobalt foods at the beginning. Often, as your gut health increases so does your ability to eat a variety of foods without overreacting.