The Chromium Debate & Other Trace Minerals
Nearly 60 years ago, chromium was proposed to be an essential element in human nutrition, but the results of new studies indicate that chromium should not be classified as an essential element. Regardless, articles still continue to appear claiming chromium is an essential element, marketed as an agent to reduce body mass and develop muscle.
Background
Chromium was thought to be an essential component of the organic complex glucose tolerance factor (the biologically active form of chromium), which stimulates the action of insulin. Chromium supplements were previously thought to reduce insulin resistance (the cause of impaired glucose tolerance).
Studies
A randomized double-blind study that examined the effects of chromium supplements in subjects with impaired glucose tolerance did not find significant improvements in glucose tolerance among those who took chromium compared with the control group.
Other studies have also found evidence undermining the essentiality of chromium in the human body.
Supplements
Chromium supplements are popular amongst people hoping to improve blood sugar control with diabetes, enhance muscle mass, or lose weight. Research has not confirmed their effectiveness for any of these conditions, and there are isolated reports of negative side effects (diarrhea, vertigo, hives, and headaches). Case reports have described kidney damage in doses of 1,200–2,400 micrograms daily for four months. Chromium supplements can interfere with many medications, among them corticosteroids, proton pump inhibitors, beta-blockers, insulin, and NSAIDs.
What About Other Trace Minerals?
RDAs (Recommended Dietary Allowances) and AIs (Adequate Intakes) were not set for certain trace minerals: aluminum, arsenic, boron, nickel, silicon, tin, and vanadium. At the time of the 2002 DRIs, not enough data was available to establish such recommendations. Most of these minerals are deemed to essential to the nutrition of specific animals and may be essential to human nutrition as well, although the complete process of their metabolism is not yet fully understood.
The available research data regarding boron, nickel, and vanadium are sufficient to establish a tolerable UL level. The adult ULs for both boron and vanadium were set on the basis of data that were gathered from animal studies. For boron, the UL is 20 mg/day; for vanadium, it is 1.8 mg/day. The adult UL for arsenic was set at 1 mg/day.
