Chromium

Supplements · Minerals · Supplement, Typed Supps

Involved in how well your cells respond to insulin.

Stage by stage

Intake (Tablet, often picolinate): Absorbed in small amounts — chromium is generally poorly absorbed regardless of form.
Small intestine (Limited absorption): Absorbed in small amounts — chromium is generally poorly absorbed regardless of form.
Bloodstream (Enhances insulin action): Appears to enhance the action of insulin at the cellular level.
Blood sugar regulation (Most studied here): Most studied in the context of blood sugar regulation.

What the evidence supports

Improving blood sugar control in type 2 diabetes — limited evidence. Trials are mixed and mostly small. Any effect appears modest and may be limited to people with low chromium status, which is hard to establish.
Producing weight loss or reducing appetite — insufficient evidence. Heavily marketed, repeatedly tested, and the pooled effect is close to nothing.
Correcting a documented deficiency — limited evidence. Genuine deficiency has only been clearly documented in long-term parenteral nutrition without added chromium.

Typical dose

Supplement trials used roughly 200 to 1,000 µg daily, usually as chromium picolinate. The larger doses are the ones tested in type 2 diabetes, and the pooled results were still modest at best.

Upper limit: No formal UL. The Food and Nutrition Board declined to set one because it could not establish a dose-response for adverse effects, not because high intakes were shown to be safe, and it noted that people with kidney or liver disease may be more susceptible.

Timing

With food, standard dosing.

Time to effect

Weeks: Any reported blood sugar effect in studies.

Medication interactions

Insulin, sulfonylureas and other glucose-lowering medication: May add to their blood-sugar-lowering effect; hypoglycaemia has been reported. If you take it, monitor glucose rather than assume nothing changes. (moderate)
Levothyroxine: Chromium picolinate taken at the same time reduces levothyroxine absorption — around a 17% drop in serum levels in one small volunteer study — so you may not get the full dose. Separate them by at least three to four hours. (moderate)
NSAIDs and aspirin: Increase chromium absorption and retention, so they raise your effective dose. Minor in itself, but it matters more if you are taking large amounts of chromium anyway. (moderate)
Antacids, H2 blockers and proton pump inhibitors: Reduce chromium absorption. The practical consequence is only that you absorb less, which given the weak evidence for benefit is not much of a loss. (moderate)
Corticosteroids: Increase chromium loss in the urine. Documented, but there is no evidence that replacing it does anything useful. (moderate)

Common myth

“Chromium meaningfully lowers blood sugar for most people.” In reality: Evidence is strongest in people with an actual deficiency or insulin resistance — much less clear otherwise.