Common Side Effects Of Taking Niacin

Niacin or nicotinic acid is a B vitamin which can be used to increase the level of high-density lipoproteins or HDLs in the body, according to MayoClinic.com. HDLs or good cholesterol can get rid of bad cholesterol or low-density lipoproteins in the blood. Niacin is available in small amounts in various foods such as dairy products or meats; niacin supplements can be obtained over the counter or by a prescription. Large doses of 1,500mg or higher are used to treat high cholesterol; niacin use at this level requires a physician's supervision, according to the Permanente Medical Group.Over-the-counter niacin should not be used in the doses large enough to lower cholesterol levels. Niacin use can be associated with side effects.

Flushing

The most common side effect of niacin is flushing of the skin on the face, arms and chest. According to The Linus Pauling Institute Micronutrient Information Center, this side effect can occur at doses as low as 30mg a day. This side effect is not dangerous; taking low-dose aspirin or other non steroidal anti-inflammatory agents like Motrin or Aleve 30 minutes prior to taking the niacin can reduce the occurrence of the flushing.

Stomach Upset

Another side effect of niacin use is gastrointestinal problems like indigestion, nausea or diarrhea, according to Drugs.com. To prevent some of these gastrointestinal issues, patients can take the niacin with a low-fat snack, according to HeartHealthWomen.org. At the higher doses, patients can develop stomach ulcers, according to the University of Maryland Medical Center website.

Liver Damage

At high doses, niacin can also cause liver damage. Liver damage has been seen in patients taking 750mg of niacin a day for three months, according to The Linus Pauling Institute Micronutrient Information Center. Time-release or slow-acting niacin preparations are more likely to cause liver failure and hepatitis than other niacin medications, according to HeartHealthWomen.org. The risk of liver damage also increases if the patient switches between different types of niacin medications without gradual titration of the dosage under the advice of a physician. The physician will monitor liver enzyme levels during niacin treatment regularly to check for signs of liver damage.

Headache

Another possible side effect of niacin may be headache. Temporary episodes of headache, dizziness and low blood pressure when standing have been reported with the use of higher doses of niacin, according to The Linus Pauling Institute Micronutrient Information Center. Drinking alcohol while taking niacin can increase the risk of dizziness, according to the 2006 version of "The AARP Guide to Pills."

Changes in Blood Sugar Levels

Very high doses of niacin -- up to 3g per day -- can cause problems with glucose tolerance, according to HeartHealthWomen.org. Niacin may increase glucose levels in the blood and cause patients who are at already at risk of developing diabetes to fully develop the disease, according to The Linus Pauling Institute Micronutrient Information Center. People who already have diabetes may develop elevated blood sugar levels that would require a modification of anti-diabetic medications.