Cobalt is an essential trace mineral that is lined to vitamin B12 and which can assist in the prevention of anemia. The amount in your body is dependent on how much was in the soil where your food was grown and although most people are not deficient it is more common with vegetarians.
Good natural sources of Cobalt are leafy green vegetables, meat, liver, milk, oysters and clams.
There are no specific symptoms of a deficiency of Cobalt but as previously indicated it is linked with vitamin B12 and therefore a deficiency in this vitamin is likely to lead to a deficiency in Cobalt. One symptom could be that the individual is exhibiting the signs of anemia.
There is no official Recommended Daily Allowance figure stated in the US however the World Health Organization recommends 1mcg.
When used therapeutically it has been found that toxicity occurred at doses over 30mg included goiter and heart failure.