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Niacin And Niacinamide (Vitamin B3)

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How does Niacin work?

Niacin is absorbed by the body when dissolved in water and taken by mouth. It is converted to niacinamide if taken in amounts greater than what is needed by the body.

Niacin is required for the proper function of fats and sugars in the body and to maintain healthy cells. At high doses, niacin might help people with heart disease because of its beneficial effects on clotting. It may also improve levels of a certain type of fat called triglycerides in the blood.

Niacin deficiency can cause a condition called pellagra, which causes skin irritation, diarrhea, and dementia. Pellagra was common in the early twentieth century, but is less common now, since some foods containing flour are now fortified with niacin. Pellagra has been virtually eliminated in western culture.

People with poor diet, alcoholism, and some types of slow-growing tumors called carcinoid tumors might be at risk for niacin deficiency.

Are there safety concerns?

Niacin is LIKELY SAFE for most people when taken by mouth. A common minor side effect of niacin is a flushing reaction. This might cause burning, tingling, 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 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.

Some concern has been raised about stroke risk in people taking niacin. In one large study, people who took high doses of niacin had a two-fold greater risk of stroke compared to those not taking niacin. However, it is unlikely that this outcome was due to niacin. Most experts believe that it is too soon to draw any conclusions about niacin and strokes.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Niacin is LIKELY SAFE for pregnant and breast-feeding women when taken in the recommended amounts. The recommended amount of niacin for pregnant or breast-feeding women is 30 mg per day for women under 18 years of age, and 35 mg for women over 18.

Allergies: Niacin might worsen allergies by causing histamine, the chemical responsible for allergic symptoms, to be released.

Heart disease/unstable angina: Large amounts of niacin can increase the risk of irregular heartbeat. Use with caution.

Crohn's disease: People with Crohn's disease might have low niacin levels and require supplementation during flare-ups.

Diabetes: Niacin might increase blood sugar. People with diabetes who take niacin should check their blood sugar carefully.

Gallbladder disease: Niacin might make gallbladder disease worse.

Gout: Large amounts of niacin might bring on gout.

Kidney disease: Niacin might accumulate in people with kidney disease. This might cause harm.

Liver disease: Niacin might increase liver damage. Don't use large amounts if you have liver disease.

Stomach or intestinal ulcers: Niacin might make ulcers worse. Don't use large amounts if you have ulcers.

Very low blood pressure: Niacin might lower blood pressure and worsen this condition.

Surgery: Niacin might interfere with blood sugar control during and after surgery. Stop taking niacin at least 2 weeks before a scheduled surgery.

Fatty deposits around tendons (tendon xanthomas): Niacin might increase the risk of infections in xanthomas.

Thyroid disorders: Thyroxine is a hormone produced by the thyroid gland. Niacin might lower blood levels of thyroxine. This might worsen symptoms of certain thyroid disorders.


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