If you are currently being treated with any of the following medications, you should not use chromium without first talking to your health care provider:
Antacids -- Animal studies suggest that antacids, particularly those containing calcium carbonate (including Tums and Mylanta), may reduce the body's ability to absorb chromium. Although it is unclear how this research relates to people, it may be advisable to avoid taking chromium supplements at the same time as antacids.
Diabetes Medications -- Chromium supplements may actually enhance the effectiveness of certain diabetes medications. Clinical studies have demonstrated that people with type 1 or type 2 diabetes who take chromium supplements may require lower doses of insulin, metformin (Glucophage), or sulfonylureas (a group of medications used to treat type 2 diabetes including glyburide or Diabeta, glipizide or Glucotrol, and chlorpropamide or Diabenese).