1. Formation of red blood cells: Cobalt is a component of vitamin B12, which is necessary for the production of red blood cells. Red blood cells carry oxygen throughout the body, and a deficiency in cobalt can lead to anemia.
2. Maintenance of the nervous system: Vitamin B12, which contains cobalt, is also important for the maintenance of the nervous system. It helps to protect the myelin sheath that surrounds nerve cells, allowing for proper communication between neurons.
3. Energy production: Cobalt plays a role in the conversion of food into energy. It is required for the production of enzymes that are involved in the breakdown of carbohydrates, fats, and proteins.
4. Immune function: Cobalt is involved in the function of the immune system. It helps to activate white blood cells, which are responsible for fighting off infections and other foreign invaders.
5. Bone health: Cobalt has been shown to play a role in bone formation and maintenance. It is required for the production of collagen, which is an important component of bone tissue.

The following are some of the sources of cobalt:

1. Animal products: Some of the best sources of cobalt are animal products like beef liver, chicken, and clams.
2. Vegetables: Vegetables like spinach, kale, collard greens, and turnip greens are good sources of cobalt.
3. Nuts and seeds: Nuts and seeds like sunflower seeds, almonds, and peanuts are good sources of cobalt.
4. Whole grains: Whole grains like wheat, oats, and barley are good sources of cobalt.
5. Seafood: Seafood like salmon, tuna, and shrimp are good sources of cobalt.
6. Fruits: Fruits like bananas and grapes are good sources of cobalt.
7. Dairy products: Dairy products like milk and cheese are good sources of cobalt.

Cobalt deficiency is rare in humans, but it can occur in individuals who have a limited intake of cobalt-rich foods or certain medical conditions that affect its absorption or utilization. Some causes of cobalt deficiency include:

1. Inadequate intake: Cobalt is found in foods such as meat, fish, dairy products, and some fortified cereals. A diet that lacks these foods can lead to cobalt deficiency.
2. Gastrointestinal disorders: Certain gastrointestinal disorders like celiac disease, Crohn’s disease, and ulcerative colitis can cause malabsorption of cobalt, leading to deficiency.
3. Vitamin B12 deficiency: Cobalt is an essential component of vitamin B12, so a deficiency in vitamin B12 can indirectly cause cobalt deficiency.
4. Prolonged use of acid-reducing drugs: Long-term use of medications that reduce stomach acid secretion, such as proton pump inhibitors or H2 blockers, can reduce the absorption of cobalt.
5. Genetic disorders: Rare genetic disorders like transcobalamin deficiency or methylmalonic acidemia can also lead to cobalt deficiency.

The symptoms of cobalt deficiency are usually similar to those of vitamin B12 deficiency (Cobalt is an essential component of vitamin B12). including:

1. Weakness and fatigue
2. Shortness of breath
3. Pale skin
4. Numbness or tingling in hands and feet
5. Confusion or memory loss
6. Depression
7. Loss of appetite
8. Diarrhea
9. Inflammation of the tongue and mouth (glossitis)

If left untreated, cobalt deficiency can lead to severe neurological and cognitive dysfunction, which can become irreversible over time. Therefore, it is essential to ensure an adequate intake of cobalt through a balanced diet or supplements if necessary.