Cobalt is another essential mineral needed in very small amounts in the diet. It is an integral part of part of vitamin B12, cobalamin, which supports red blood cell production and the formation of myelin nerve coverings. Some authorities do not consider cobalt to be essential as a separate nutrient, since it is needed primarily as part of B12, which is itself essential.
Cobalt, as part of vitamin B12, is not easily absorbed from the digestive tract. The body level of cobalt normally measures 80-300 mcg. It is stored in the red blood cells and the plasma, as well as in the liver, kidney, spleen, and pancreas.
Sources: Cobalt is available mainly as part of B12. There is some question as to whether inorganic cobalt is actually usable in the human body. Meat, liver, kidney, clams, oysters, and milk all contain some cobalt. Ocean fish and sea vegetables have cobalt, but land vegetables have very little; some cobalt is available in legumes, spinach, cabbage, lettuce, beet greens, and figs.
Functions: As part of vitamin B12, cobalt is essential to red blood cell formation and is also helpful to other cells.
Uses: Cobalt, as part of B12, is used to prevent anemia, particularly pernicious anemia; vitamin B12 is also beneficial in some cases of fatigue, digestive disorders, and neuro-muscular problems. There are no other known uses except for the radioactive cobalt-60 used to treat certain cancers.
Deficiency and toxicity: Toxicity can occur from excess inorganic cobalt found as a food contaminant. Beer drinker's cardiomyopathy (enlarged heart) and congestive heart failure have been traced to cobalt introduced into beer during manufacturing. Increased intake may affect the thyroid or cause overproduction of red blood cells, thickened blood, and increased activity in the bone marrow.
Deficiency of cobalt is not really a concern if we get enough vitamin B12. Vegetarians need to be more concerned than others about getting enough cobalt and B12. The soil is becoming deficient in cobalt, further reducing the already low levels found in plant foods. As cobalt sdeficiency leads to decreased availability of B12, there is an increase of many symptoms and problems related to B12 deficiency, particularly pernicious anemia and nerve damage.
Requirements: No specific RDA is suggested for cobalt. Our needs are low, and vitamin B12 usually fulfills them. The average daily intake of cobalt is about 5-8 mcg. It is not usually given in supplements.