What type of niacin

The timed-release tablets and capsules may have fewer side effects than regular niacin. However, the timed-release versions are more likely to cause liver damage. Regardless of which form of niacin you are using, doctors recommend periodic liver function tests when using high doses above mg per day of niacin.

Generally, high doses of niacin are used to control specific diseases. Such high doses must be prescribed by a doctor who will increase the amount of niacin slowly, over the course of 4 to 6 weeks. Take niacin with meals to avoid stomach irritation. Because of the potential for side effects and interactions with medications, you should take dietary supplements only under the supervision of a knowledgeable health care provider.

Side effects may include diarrhea, headache, stomach discomfort, and bloating. High doses 50 mg or more of niacin can cause side effects. The most common side effect is called "niacin flush," which is a burning, tingling sensation in the face and chest, and red or flushed skin. Taking an aspirin 30 minutes prior to the niacin may help reduce this symptom. At very high doses, used to lower cholesterol and treat other conditions, liver damage and stomach ulcers can occur.

Your doctor will regularly check your liver function through a blood test. People with a history of liver disease, kidney disease, or stomach ulcers should not take niacin supplements. Those with diabetes or gallbladder disease should do so only under the close supervision of their doctors.

People with low blood pressure should not take niacin or niacinamide because they may cause a dangerous drop in blood pressure. DO NOT take niacin if you have a history of gout. People with coronary artery disease or unstable angina should not take niacin without their doctor's supervision, as large doses can raise the risk of heart rhythm problems. Taking any one of the B vitamins for a long period of time can result in an imbalance of other important B vitamins.

For this reason, you may want to take a B-complex vitamin, which includes all the B vitamins. Because of its impact on the liver, vitamin B3 can interact with several medications. If you are currently taking medications, or regularly drink alcohol, you should not use niacin without talking to your health care provider first.

Below is a partial list of medications that may interact with vitamin B3. Antibiotics, tetracycline: Niacin should not be taken at the same time as the antibiotic tetracycline because it interferes with the absorption and effectiveness of this medication. All vitamin B complex supplements act in this way and should be taken at different times from tetracycline. Aspirin: Taking aspirin before taking niacin may reduce flushing from niacin. But take it only under your doctor's supervision.

Anti-seizure medications: Phenytoin Dilantin and valproic acid Depakote may cause niacin deficiency in some people. Taking niacin with carbamazepine Tegretol or mysoline Primidone may increase levels of these medications in the body. Anticoagulants blood thinners : Niacin may make the effects of these medications stronger, increasing the risk of bleeding.

Blood pressure medications, alpha-blockers: Niacin can make the effects of medications taken to lower blood pressure stronger, leading to the risk of low blood pressure.

Cholesterol-lowering medications: Niacin binds the cholesterol-lowering medications known as bile-acid sequestrants and may make them less effective. For this reason, niacin and these medications should be taken at different times of the day. Bile-acid sequestrants include colestipol Colestid , colesevelam Welchol , and cholestyramine Questran.

Statins: Some scientific evidence suggests that taking niacin with simvastatin Zocor appears to slow the progression of heart disease. However, the combination may also increase the likelihood for serious side effects, such as muscle inflammation or liver damage.

Diabetes medications: Niacin may increase blood sugar levels. People taking insulin, metformin Glucophage , glyburide Dibeta, Micronase , glipizide Glucotrol , or other medications used to treat high blood glucose levels should monitor their blood sugar levels closely when taking niacin supplements.

Nicotine patches: Using nicotine patches with niacin may worsen or increase the risk of flushing associated with niacin. The role of niacin in raising high-density lipoprotein cholesterol to reduce cardiovascular events in patients with atherosclerotic cardiovascular disease and optimally treated low-density lipoprotein cholesterol Rationale and study design.

Am Heart J. Niacinamide: A B vitamin that improves aging facial skin appearance. Dermatol Surg. Toth PP. In their report, these two professional societies stated what although niacin may be useful in some cases of severe hypertriglyceridemia, it has only mild LDL-lowering effects.

The societies therefore do not recommend using it as an add-on drug to statin therapy [ 34 ]. Overall, the evidence indicates that nicotinic acid supplementation improves blood lipid profiles but has no significant effects on risk of cardiovascular events. Although nicotinic acid is a nutrient, if very high doses thousands of mg are taken to treat hyperlipidemias, the supplement is being used as a drug.

Such doses should only be taken with medical approval and supervision. No adverse effects have been reported from the consumption of naturally occurring niacin in foods [ 2 ]. However, high intakes of both nicotinic acid and nicotinamide taken as a dietary supplement or medication can cause adverse effects, although their toxicity profiles are not the same.

The flushing is accompanied by burning, tingling, and itching sensations [ 2 , 12 , 35 ]. These signs and symptoms are typically transient and can occur within 30 minutes of intake or over days or weeks with repeated dosing; they are considered an unpleasant, rather than a toxic, side effect. Supplement users can reduce the flushing effects by taking nicotinic acid supplements with food, slowly increasing the dose over time, or simply waiting for the body to develop a natural tolerance.

Many of these effects have occurred in patients taking high-dose nicotinic acid supplements to treat hyperlipidemias. These adverse effects can include hypotension severe enough to increase the risk of falls; fatigue; impaired glucose tolerance and insulin resistance; gastrointestinal effects, such as nausea, heartburn, and abdominal pain; and ocular effects, such as blurred or impaired vision and macular edema a buildup of fluid at the center of the retina.

High doses of nicotinic acid taken over months or years can also be hepatotoxic; effects can include increased levels of liver enzymes; hepatic dysfunction resulting in fatigue, nausea, and anorexia; hepatitis; and acute liver failure [ 2 , 12 , 28 , 36 ]. Hepatotoxicity is more likely to occur with the use of extended-release forms of nicotinic acid [ 12 , 37 , 38 ]. To minimize the risk of adverse effects from nicotinic acid supplementation or to identify them before they become serious, the American College of Cardiology and the American Heart Association recommend measuring hepatic transaminase, fasting blood glucose or hemoglobin A1C, and uric acid levels in all supplement users before they start therapy, while the dose is being increased to a maintenance level, and every 6 months thereafter [ 28 ].

The societies also recommend that patients not use nicotinic acid supplements or stop using them if their hepatic transaminase levels are more than two or three times the upper limits of normal; if they develop persistent hyperglycemia, acute gout, unexplained abdominal pain, gastrointestinal symptoms, new-onset atrial fibrillation, or weight loss; or if they have persistent and severe skin reactions, such as flushing or rashes.

Nicotinamide does not cause skin flushing and has fewer adverse effects than nicotinic acid, and these effects typically begin with much higher doses [ 12 ]. The FNB has established ULs for niacin that apply only to supplemental niacin for healthy infants, children, and adults [ 2 ]. These ULs are based on the levels associated with skin flushing. The FNB acknowledges that although excess nicotinamide does not cause flushing, a UL for nicotinic acid based on flushing can prevent the potential adverse effects of nicotinamide [ 2 ].

The UL, therefore, applies to both forms of supplemental niacin. However, the UL does not apply to individuals who are receiving supplemental niacin under medical supervision [ 2 ].

Niacin can interact with certain medications, and several types of medications might adversely affect niacin levels. A few examples are provided below. Individuals taking these and other medications on a regular basis should discuss their niacin status with their healthcare providers.

In addition, isoniazid can interfere with niacin's conversion to NAD [ 42 ]. Although pellagra can occur in patients with tuberculosis treated with isoniazid, it can be prevented with increased intakes of niacin.

Antidiabetes medications Large doses of nicotinic acid can raise blood glucose levels by causing or aggravating insulin resistance and increasing hepatic production of glucose [ 42 ]. Some studies have found that nicotinic acid doses of 1. People who take any antidiabetes medications should have their blood glucose levels monitored if they take high-dose nicotinic acid supplements concomitantly because they might require dose adjustments [ 42 ].

The federal government's — Dietary Guidelines for Americans notes that "Because foods provide an array of nutrients and other components that have benefits for health, nutritional needs should be met primarily through foods. In some cases, fortified foods and dietary supplements are useful when it is not possible otherwise to meet needs for one or more nutrients e.

For more information about building a healthy dietary pattern, refer to the Dietary Guidelines for Americans and the U. Department of Agriculture's MyPlate. This fact sheet by the Office of Dietary Supplements ODS provides information that should not take the place of medical advice.

We encourage you to talk to your healthcare providers doctor, registered dietitian, pharmacist, etc. Any mention in this publication of a specific product or service, or recommendation from an organization or professional society, does not represent an endorsement by ODS of that product, service, or expert advice. Updated: March 26, History of changes to this fact sheet. Find ODS on:. Strengthening Knowledge and Understanding of Dietary Supplements. Health Information Health Information.

Niacin Fact Sheet for Health Professionals. Present Knowledge in Nutrition, 10th ed. Washington, DC: Wiley-Blackwell; Institute of Medicine. Food and Nutrition Board. Kirkland JB. Modern Nutrition in Health and Disease, 11th ed. Bourgeois C, Moss J. Encyclopedia of Dietary Supplements, 2nd ed. Gibson, RS. Principles of Nutritional Assessment, Second Edition.

New York: Oxford University Press. However, after a study published in the New England Journal of Medicine found that niacin provided no benefit to people with high cholesterol, the practice was stopped.

Today, niacin is used mainly to treat niacin deficiency, which if severe can lead to pellagra , a disease characterized by diarrhea, skin lesions, and dementia. Niacin deficiency is most likely to develop as a result of malnutrition, poverty, or chronic alcoholism. Most people get enough niacin in their diets to prevent a deficiency, particularly from foods like yeast, meat, fish, milk, eggs, green vegetables, and fortified cereal. However, if your healthcare provider or nutritionist says you need more vitamin B3 in your diet, there are things to consider in order to choose the appropriate niacin supplement.

The U. Department of Health and Human Services recommends 14 milligrams mg of niacin per day for women and 16 mg of niacin day for men from all sources. Immediate-release IR nicotinic acid, also known as "fast-release" nicotinic acid, empties the entire dose into the bloodstream as soon as it's swallowed. For this reason, IR nicotinic acid is more likely than other forms of the vitamin to cause side effects.

If the label doesn't say which form of nicotinic acid is in the bottle, it's safe to assume that it's an IR product. This form of nicotinic acid is available by prescription under the brand names Niaspan or Niacor, as well as generically.

There also is a controlled-release version called Slo-Niacin that's sold over the counter and may be less expensive. Extended-release ER nicotinic acid is released into the body more slowly than the IR type.

Extended-release nicotinic acid may cause side effects but these are likely to be less severe than those associated with the IR form. Sustained-release SR nicotinic acid, also known as "timed-release" nicotinic acid, releases nicotinic acid into the body over a period of time rather than all at once.

It may still cause side effects, but they're likely to be milder than those brought on by immediate-release supplements. An SR nicotinic acid supplement will take longer to clear the body than either an IR form or an extended-release ER form.

For this reason, SR nicotinic acid comes with the risk of liver toxicity. If you have a liver disease such as cirrhosis or chronic hepatitis B or C infection , it's best not to take sustained-release niacin and to opt for an immediate- or extended-release formulation instead.

Niacin supplements are safe for most people, but there are some potential side effects to be aware of. The most common is flushing—warmth, tingling, itching, and redness of the face, arms, and chest. Evaluating the incremental benefits of raising high-density lipoprotein cholesterol levels during lipid therapy after adjustment for the reductions in other blood lipid levels.

Archives of Internal Medicine. Singh IM, et al. High-density lipoprotein as a therapeutic target: A systematic review. Journal of the American Medical Association. Cholesterol-lowering drugs.

American Heart Association. Guyton JR, et al. Safety considerations with niacin therapy. American Journal of Cardiology. Food and Drug Administration. Accessed May 27, See also After a flood, are food and medicines safe to use? Arcus senilis: A sign of high cholesterol? Get moving Cholesterol concerns?

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