Chromium is an essential trace element, meaning that the human body needs it in very small amounts.
Pure chromium has a shiny silver colour, its name comes from the Greek word chroma, meaning ‘colours’. Emeralds derive their green colour from the small amount of chromium they contain.
Only around 0.4% to 2.5% of chromium is absorbed from the intestinal tract but the level of absorption is enhanced by vitamin C and the B vitamin niacin. When absorbed it is stored in the liver, spleen, soft tissue, and bone. Diets high in simple sugars can increase chromium excretion in the urine leading to low levels in the body, as can infection, too much exercise, pregnancy, lactation, and stress from any cause.
Chromium supplements, or multivitamin supplements with chromium may be useful for several conditions as well as for correcting any chromium deficiency.
Diabetes - Several studies have found that chromium supplements may improve diabetes control. But a review of randomised controlled clinical trials found overall, chromium supplementation had little effect on glucose or insulin concentrations in people without diabetes nor did it reduce these levels in people with diabetes except in one study. Therefore overall the value of chromium supplements for diabetes is inconclusive.
High cholesterol - Chromium supplementation may improve blood lipid levels. Some studies are negative but some are positive, including a double blind, placebo controlled 4-week study which found that taking a chromium supplement significantly decreased levels of LDL cholesterol and slightly increased levels of HDL cholesterol compared to a placebo.
Weight loss - this is more promising with several studies finding that this mineral can enhance the action of insulin leading to a lower appetite and burning off more calories thereby promoting weight loss. A review found chromium to be one of the most effective dietary supplements with the 10 double-blind studies of chromium picolinate showing an average reduction of 1.1–1.2 kg during the intervention period of 6–14 weeks.
Atypical depression - finally, chromium supplementation may be of benefit for a completely different condition. Atypical depression is a form of the disease characterised by excessive sleeping, increased appetite, quick mood changes and being hypersensitive to rejection. A small study found 70% of patients taking the chromium had a significant improvement whereas no one in the placebo group did. The mechanism by which it may help depression is not known.
For most people, sufficient amounts of chromium are relatively easy to obtain from a healthy diet as it is present in many foods such as potatoes, broccoli, green beans, brown bread, pasta, rice and many fruits. However supplements would likely be needed to reach the higher doses required to help with the conditions listed above.
There is no established safe upper limit for chromium supplementation but in studies it has been safely used by adults in doses of up to 1000mcg per day for periods of up to six months, much higher than the daily recommended intake of around 50mcg for teenagers and 200mcg for adults.