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Other name(s):

cobalamin, cyanocobalamin, hydroxyocobalamin

General description

Cobalt is a hard gray metal element. It’s part of vitamin B-12. This vitamin is essential for making red blood cells. It also maintains the nervous system.

Cobalt is only in the body as part of vitamin B-12. It’s needed for making red blood cells (erythropoiesis).

Cobalt has some of the same jobs as manganese and zinc. It can replace manganese in activating several enzymes. These are called biochemical reaction activators. It can also replace zinc in some biochemical reactions.

Cobalt is also part of the biotin-dependent Krebs-cycle. This is the process that the body uses to break down sugars into energy.

Medically valid uses

As part of B-12, cobalt prevents pernicious anemia. It’s also needed to keep the nervous system working well.

Unsubstantiated claims

There are no claims based upon cobalt as a single element.

Recommended intake

As part of supplements, cobalt is measured in micrograms (mcg). The average adult intake of cobalt is 5–8 mcg per day. A safe Recommended Dietary Allowance (RDA) for cobalt hasn’t been set yet.

Trace amounts of cobalt are found in most foods. Foods high in vitamin B-12 are the only source of cobalt used by the body.

It’s best to take cobalt in vitamin B-12.

If you have a cobalt deficiency, this also means you have a vitamin B-12 deficiency. Anemia is a main cause of a cobalt deficiency. This is the case with pernicious anemia. Symptoms can include numbness, fatigue and tingling in your hand and feet. Over time, the condition also leads to decreased nerve function.

Side effects, toxicity, and interactions

Cobalt is toxic to the heart muscle. It can cause heart muscle disease (toxic cardiomyopathy) after too much exposure.

An increase in red blood cells (polycythemia) may be a symptom of too much cobalt. Not treating this issue can cause congestive heart failure.

Too much intake of cobalt may cause enlargement of the thyroid gland (goiter). It can also reduce the activity of the thyroid. Cobalt may also increase blood sugar levels.

Since cobalt is a key part of vitamin B-12, people with Leber's syndrome, a rare eye condition, should not take it without talking to their healthcare providers. Some forms of vitamin B-12 may lead to vision loss in people with this issue.

Women who are pregnant or breastfeeding should talk to their healthcare providers before taking any supplements.

There are no known food or medicine interactions with cobalt.

There have been reports of high levels of cobalt in people who had hip replacements that used a metal-on-metal devices. Symptoms of a higher level of cobalt in blood are:

  • Fatigue

  • Weakness

  • Peripheral neuropathy

  • Hearing loss

  • Visual loss

  • Cognitive decline

  • Cardiomyopathy

  • Hypothyroidism

Online Medical Reviewer: Cynthia Godsey
Online Medical Reviewer: Diane Horowitz MD
Online Medical Reviewer: Rita Sather RN
Date Last Reviewed: 1/1/2019
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