What You Should Know About Niacin Supplements

A Guide to Choosing the Right One

In This Article

Niacin is a form of vitamin B, specifically B3 (nicotinic acid). It is a water-soluble vitamin important for proper cell function in the body. Niacin has been studied for its potential to treat an array of diseases (including Alzheimer's disease, cataracts, erectile dysfunction, and sickle cell disease) with little success.

At one time, doctors prescribed niacin to help manage cholesterol in people with cardiovascular disease. However, after a 2011 study published in the New England Journal of Medicine found that niacin provided no benefit to people with high cholesterol, the practice was largely stopped.

Today, niacin is mainly used 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 doctor 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.S. Department of Health and Human Services recommends 14 mg of niacin per day for women and 16 mg of niacin day for men from all sources.

Immediate-Release Nicotinic Acid

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.

Some bottles of nicotinic acid may not state if they contain an “immediate-release” or a “sustained-release” (see below) product. 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.

Sustained-Release Nicotinic Acid

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 form of nicotinic acid will take the longest of the three forms to completely leave the body. That means that it stays in the body longer than the IR or ER form. For this reason, SR nicotinic acid may increase the risk of liver toxicity in those who take it.

If you have 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.

Extended-Release Nicotinic Acid

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.

The rate at which extended-release (ER) nicotinic acid is released into the body lies somewhere between that of the IR and SR formulations—a little slower than the IR type, but more quickly than the SR version.

Extended-release nicotinic acid may cause side effects but as with sustained-release nicotinic acid, they're likely to be less severe than with the IR form.

Additionally, there are no problems with liver toxicity associated with this form of nicotinic acid.

Possible Side Effects

Niacin is are safe for most people, but there are some potential side effects to be aware of if you will be taking it. The most common side effect of nicotinic acid supplements is flushing—warmth, tingling, itching, and redness of the face, arms, and chest. This symptom may be accompanied by headache, dizziness, rash, and/or a decrease in blood pressure.

These side effects can be aggravating and, in some cases, intolerable, but usually subside after a couple of weeks. In the meantime, there are ways to mitigate them.

  • Ease into a full dose. For instance, if you are supposed to take 500 milligrams (mg) per day, take 250 mg the first few days and gradually increase to full strength as tolerated.
  • Switch formulations. If immediate-release niacin causes problems, a sustained-release formulation (available over the counter) or extended-release formulation (prescription only) may be better tolerated as the niacin is delivered gradually rather than all at once.
  • Divide the dose. Rather than take the entire dose all at once, take half in the morning and half at night. (Although you can physically split an immediate-release niacin tablet in two, never cut, chew, or dissolve a sustained- or extended-release tablet.)
  • Avoid alcohol and hot beverages. Consuming either can make side effects worse. Until they fully resolve, cut back on alcohol and hot coffee, tea, or other drinks as much as you can or stop altogether.
  • Take aspirin. Studies have shown that taking aspirin 30 minutes before or at the same time as niacin can decrease the intensity and duration of flushing by 30% to 40%.
  • Try flush-free niacin. This combination supplement contains nicotinamide and inositol hexaniacinate. Although better tolerated than other forms of niacin, research has shown that "flush-free" niacin is no better than a placebo at improving cholesterol and other lipid levels.

High doses of nicotinic acid (more than 3 grams per day) may cause severe side effects, including liver damage, gout, gastrointestinal ulcers, vision loss, high blood sugar, irregular heartbeat, and other serious problems. High-dose niacin also has been associated with an increased risk of stroke.

Dosage and Preparation

There is not enough scientific data to provide a single recommended dose of niacin or nicotinic acid. The appropriate dose for you may depend on your age, gender, medical history, and other factors, which your doctor will take into consideration if they decide to prescribe nicotinic acid for you.

If you want to take OTC niacin, talk to your healthcare provider first to make sure it makes sense for you to do so. Together you can determine the optimal formulation and dose.

What to Look For

Whether you're buying niacin over the counter or will be taking it by prescription, don't think of it as "only a supplement." It is still a form of medication that has risks and side effects. Get your doctor's OK before you start taking a niacin supplement, and report any significant side effects right away.

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Article Sources

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