Any time you eat foods that contain carbohydrates -- all foods except meat and fat -- your glucose levels rise. Your glucose levels naturally fall as you digest your food. But if you have type 2 diabetes or prediabetes, your glucose levels may remain high long after you've completed a meal. Persons with diabetes need to carefully manage the carbohydrates in their diets and exercise great caution when taking niacin and other medications that can elevate their fasting glucose levels.
Niacin and Diabetes
Persons with type 1 diabetes may want to take niacinamide, a type of niacin, specifically to treat symptoms of their disease. Niacinamide may help prevent type 1 diabetes and, for persons already diagnosed with the disease, may delay their need for taking insulin. If you have type 2 diabetes, taking niacin --- but not niacinamide --- may help you improve your high-density lipoprotein, the "good" cholesterol that pulls unhealthy low-density lipoprotein and triglycerides out of your system. But because niacin can elevate your blood sugar levels, you should not take niacin without a doctor's supervision.
Managing Glucose Levels
If you have diabetes and take niacin supplements, monitor your blood glucose levels frequently. If you take insulin, metformin, glipizide, glyburide or other medications to treat diabetes, you may need to alter your medication schedule or dose if you take niacin. Inform your doctor about unusual fluctuations in your fasting glucose levels. Although niacin proves effective for treating high cholesterol and hardening of the arteries, other available remedies may help without harming your glucose levels.
Skin Flushes and Other Side Effects
You can purchase niacin without a prescription. Over-the-counter medications marketed as no-flush niacin contain niacinamide rather than regular niacin. No-flush niacin helps prevent skin flushes, a side effect that makes your face and chest turn red as well as itch, tingle and burn. Both niacin prescribed by your doctor and niacinamide purchased at a drugstore can elevate your fasting glucose levels and cause other side effects, such as stomach ulcers, gout and liver damage.
Dietary Niacin
Your diet also includes niacin. Foods such as fish, beets and sunflower seeds contain niacin. Some other foods --- chicken and eggs, for instance --- contain tryptophan, an enzyme that converts to niacin in your bloodstream. Eating these foods will unlikely affect your fasting glucose levels. But if you eat a lot of some foods --- peanuts, for instance --- you may consume enough niacin to cause unusual elevations. Persons with diabetes can certainly eat peanuts but should exercise portion control.
