Niacin And Niacinamide (Vitamin B3)
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itching, and redness of the face, arms, and chest, as well as headaches. Starting with small doses of niacin and taking 325 mg of aspirin before each dose of niacin will help reduce the flushing reaction. Usually, this reaction goes away as the body gets used to the medication. Alcohol can make the flushing reaction worse. Avoid large amounts of alcohol while taking niacin.
Other minor side effects of niacin and niacinamide are stomach upset, intestinal gas, dizziness, pain in the mouth, and other problems.
When doses of over 3 grams per day of niacin are taken, more serious side effects can happen. These include liver problems, gout, ulcers of the digestive tract, loss of vision, high blood sugar, irregular heartbeat, and other serious problems. Similar side effects can happen with large doses of niacinamide.
Niacinamide seems to be safe when used appropriately in children.
Niacin and niacinamide are also safe for pregnant and breast-feeding women when taken in the recommended amounts. The recommended amount of niacin is 18 mg per day during pregnancy and 19 mg per day while breast-feeding.
Niacin and niacinamide might increase blood sugar. People with diabetes who take niacin or niacinamide should check their blood sugar carefully.
Do not use niacin or niacinamide if:
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.