It's considered a high dose when a patient takes 75 mgs or more of niacin. The level of niacin that causes side effects varies from person to person. Some of the side effects of large doses of niacin include skin complaints, indigestion, liver problems, hyperglycemia, birth defects, and arrhythmias.
Skin side effects of toxicity when using niacin include dry skin, flushing, itching and rashes. Some people also report a prickly or tingling feeling on the skin. One of the rashes that can occur when using large doses of niacin is called Acanthuses Nigerians. Acanthus Nigerians is when dark patches of fuzzy skin occur due to too much niacin. This skin problem is usually found on the neck, arms or in the groin area.
Flushing is another side effect of large doses of niacin. Flushing has been compared to a hot flash, and is an inconvenient and uncomfortable side effect of niacin therapy. Flushing is a sign that niacin is at work in the patient's system.
Indigestion is another side effect of a toxic reaction to large doses of niacin. Gas, nausea, and diarrhea can also occur. Ulcers can be caused as a side effect of large doses of niacin, as well. Dark stools are a severe reaction to niacin and can indicate internal bleeding. Dark stools should be reported to a doctor immediately.
Liver problems and liver failure are also side effects of large dose niacin therapy. Yellow in the eyes is a liver side effect that occurs in rare occasions in people taking larger doses of niacin.
Diabetic people may not want to use niacin therapy, since niacin increases blood sugar levels. Niacin is used to reduce high triglycerides, which are an indicator of diabetes. High blood sugar resulting from the use of large doses of niacin counteracts niacin's benefits, however.
You don't want to use larger doses of niacin during pregnancy. Pregnant women taking large doses of niacin can give their babies birth defects. Pregnant women should consult a physician before taking any kind of medication or supplement, to avoid problems with the developing baby.
Some researchers and health care givers have recommended niacin therapy for several medical conditions. People with high cholesterol, high triglycerides, and risk of heart attack are sometimes given therapeutic doses of niacin to lower cholesterol and lessen the risk of heart attack. You need to be aware that there are side effects when using higher doses of niacin however. These side effects range from the annoying to dangerous health problems.
