Chromium is an essential component of glucose tolerance factor (GTF), which enhances insulin function, making it vital for proper carbohydrate metabolism and for regulating blood sugar levels. By improving how glucose is transported into the cells, chromium and GTF are also important for energy production. Research suggests that chromium may also be useful for regulating body cholesterol levels.

One of the best food sources of chromium is brewer's yeast. Other food sources include wholegrain breads and cereals, wheat germ, eggs, meats, and shellfish.
Cobalt, in addition to being a component of cobalamin (vitamin B12), plays an essential role in the production of red blood cells, and is involved in a number of enzymatic reactions. Adequate vitamin B12 intake normally provides sufficient amounts of cobalt to the body. Food sources include beet greens, cabbage, figs, legumes, lettuce, liver, and sea fish and sea vegetables. Cobalt deficiencies are similar to those caused by a lack of B12, including anaemia and nerve damage.