What are Vitamin B3 or niacin's side effects?
Vitamin B3, also known as niacin (nicotinic
acid), usually has very few side effect at the recommended dosage of 14 mg per day for women
and 16 mg per day for men. Niacin is typically use for the treatment of high cholesterol.
However, there is a potential for niacin to cause severe side effects at doses at or greater
than 1 gram per day. Side effects that result from high dosage include headache, flushing,
burning, tingling or itching sensations, blurred vision, heartburn, nausea, vomiting, diarrhea
and bloating. If you begin to experience faintness, fast heartbeat, dizziness or yellowing of
the eyes or skin, call your doctor immediately as these symptoms may indicate liver toxicity in
The chance of flushing side effects can be reduced if Vitamin B3 is taken after food or if aspirin is taken half an hour to 45 minutes prior to taking niacin. These side effects can also be reduced when dosage is increased gradually over time to the prescribed dosage. It can also be reduced if given an extended release variety like Niaspan®. Niacin is typically only prescribed for high cholesterol under the close supervision of a physician.
Learn more about high cholesterol in our Health Encyclopedia.
If you're looking for more specific answers to specific questions, ask a Walgreens pharmacist here.