If you're worried about your cholesterol level and have started exercising and eating healthier foods, you might wonder if a dietary supplement could help. With your doctor's OK, here are some cholesterol-improving supplements to consider.

Some red yeast rice products contain a substance (monacolin K) that is chemically identical to the active ingredient in lovastatin (Altoprev), a prescription medication that lowers cholesterol. Because there is variability in quality from manufacturer, the amount of monacolin K can vary widely from product to product.

Products that contain monacolin K can cause the same types of side effects as lovastatin, which include damage to the muscles, kidneys and liver. In the United States, the Food and Drug Administration has ruled that dietary supplements that contain more than trace amounts of monacolin K are unapproved drugs and can't be sold legally as dietary supplements.

While dietary supplements can help, you might also need prescription medications to get your cholesterol numbers to a safe level. Be sure to tell your doctor if you take any type of dietary supplement, because some can interact with medications you may be taking.