Common side effects of niacin.

If you eat foods rich in niacin, the chances that you overeat it are very small. However, side effects of niacin may occur when taking supplements, especially at high dosages.

Here are some side effects that occur most often when taking large doses:
• nausea or vomiting;
• skin reactions, rash;
• headache;
• dizziness;
• allergic reactions;



• heart problems (high doses may increase the risk of irregular heartbeat);
• diabetes: niacin and niacinamide can increase blood sugar;
• deterioration of the gallbladder and symptoms of liver disease;
• exacerbation of symptoms of gout;
• low blood pressure;
• an ulcer of the stomach or intestines.

If you are taking any medications or supplements daily, be sure to notify your doctor. Otherwise, negative side effects of niacin may occur.