Serum chromium is a test for abnormal levels of chromium in the blood.

Blood is drawn from a vein, usually from the inside of the elbow or the back of the hand. The site is cleaned with germ-killing medicine (antiseptic). The health care provider wraps an elastic band around the upper arm to apply pressure to the area and make the vein swell with blood.

Next, the health care provider gently inserts a needle into the vein. The blood collects into an airtight vial or tube attached to the needle. The elastic band is removed from your arm.

Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

In infants or young children, a sharp tool called a lancet may be used to puncture the skin and make it bleed. The blood collects into a small glass tube called a pipette, or onto a slide or test strip. A bandage may be placed over the area if there is any bleeding.

No special preparation is necessary for this test.

When the needle is inserted to draw blood, you feel moderate pain, or only a prick or stinging sensation. Afterward, there may be some throbbing.

This test may be done to diagnose chromium poisoning or deficiency.

Serum chromium levels normally range from less than 0.05 up to 0.5 micrograms/milliliter (mg/mL).

The range of normal values depends on the type of specimen tested and may vary between different laboratories.

Increased chromium levels may result if you are overexposed to the substance when you work in the following industries:

• Leather tanning
• Electroplating
• Steel manufacturing

Decreased chromium levels usually occur in people who receive all of their nutrition by vein (total parenteral nutrition or TPN).

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Test results may be altered if the sample is collected in a metal tube.

Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 237.