Niacin, also known as nicotinic acid or vitamin B-3, helps in the functioning of the digestive system, skin and nerves, but it can cause harmful side effects and interact with certain medicines, such as those for your diabetes. Niacin should not be used for self-management of your diabetes, or to replace any of your current medicines or dietary restrictions, without advice from your doctor.
About Niacin
Niacin can be found naturally in plants and animals, and is sometimes added to multiple vitamins or nutritional supplements. Niacin is available as either over-the-counter supplements or prescription medication. As a supplement, it is often simply labeled as niacin. However, when used to correct a niacin deficiency or as a treatment to lower cholesterol and triglycerides in your blood, it is available as a prescription medicine. Brand name prescription preparations include Niaspan, Niacor and Slo-Niacin.
Common Adverse Effects
According to the National Institutes of Health, niacin is likely safe for most people when taken orally. However, niacin may cause high blood sugar levels. If you have diabetes and are taking niacin, you should watch your blood sugar levels closely. Other common adverse effects of niacin include flushing, gastrointestinal problems such as nausea, vomiting or diarrhea; and peptic ulcers.
Diabetes Medication Effects
The increase in your blood sugar caused by niacin may affect how your diabetes medicines are working. If you take insulin or oral diabetes medicines, your dose may need to be changed because niacin may increase the amount of sugar in your blood and urine. Make sure to check your blood sugar levels regularly when taking niacin. Do not take it without consulting your doctor if you have diabetes.
Considerations
Niacin can also damage your liver and increase the risk of gout, says the NIH. If you are diabetic and taking medicine for high blood pressure, niacin may also increase their potency, so check your blood pressure often, warns the NIH. Use niacin with caution if you have severe liver or kidney disease, heart disease, gallbladder disease, stomach ulcers, active bleeding, or a muscle disorder, such as myasthenia gravis.
