What to Do if You Have a Niacin Reaction

It's unlikely that you have a deficiency of niacin — also known as vitamin B3 — if you're including meat, dairy and fortified grains in your diet and don't have a specific difficulty with absorbing it. However, your doctor or naturopath might prescribe niacin to treat blood lipid disorders, such as high cholesterol and high triglycerides, as an alternative to statins. The vitamin has fewer side effects than statin treatment does, but it can cause a niacin reaction of flushed, prickly-feeling skin similar to a moderate case of sunburn.

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Although you might be instructed to take as much as 2,000 milligrams of niacin per day to help your blood lipid levels, as little as 50 milligrams can cause a flush. This reaction is due to the vitamin causing capillaries near the surface of the skin to dilate, bringing more blood to the area.

A niacin reaction typically involves a warm, flushed feeling in your face that may be accompanied by sharp tingles. The feeling moves down your neck to your arms and chest, seldom progressing any further.

Depending on the severity of the niacin reaction, it could feel like pleasant warming of the skin or like a severe sunburn combined with pricks from little needles. The unpleasantness of many niacin reactions is why many people taking vitamin B3 opt to quit.

Reactions are most common in people who consume niacin in the form of nicotinic acid that is delivered in an immediate-release formula. Up to 50 percent of people taking this form of the vitamin experience the niacin flush, according to the Mercola website.

If your skin starts to tingle and prickle, keeping yourself cool is the best treatment. Take a cool shower, put a cool washcloth on your face or turn the air conditioner to its coldest setting and stand in the cool breeze. In winter, eschew the coat and go stand outside for a few minutes to help the capillaries under your skin constrict.

On the other hand, anything that will cause your capillaries to dilate will make your symptoms feel worse. Stay out of direct sunlight and don't even dream of treating your tingling skin with a heating pad, hot water bottle or a dip in the hot tub. Forgo that alcoholic beverage or spicy food — both of which will intensify the flush — until after your symptoms have subsided, which could be anywhere from a few minutes to two hours. Zinc tablets and some other herbal supplements can also make you more likely to experience the niacin prickles.

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Although niacin flush can be unpleasant, it's not dangerous. However, large doses of niacin in amounts greater than 2,000 milligrams can cause potentially serious side effects, according to the Mayo Clinic. Call your doctor if you experience any of these symptoms:

• Severe flushing and itchiness combined by dizziness
• Rapid heartbeat
• Nausea, vomiting, diarrhea or abdominal pain

Ingesting large doses of niacin over the long term can result in additional health issues, including diabetes, gout and liver damage.

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Taking an alternative form of niacin can reduce your risk of experiencing unpleasant flushing.

Sustained-release tablets release niacin into your system over many hours. Because the vitamin enters your bloodstream a little at a time, the likelihood of experiencing niacin flush is greatly reduced. However, the fact that your liver has to process the vitamin over many hours can cause liver damage in some people.

No-flush niacin tablets contain ​inositol nicotinate​, a substance that reportedly converts slowly to niacin in the body. However, the amount of actual niacin delivered to the body is minimal — hence no flushing. The small amount of vitamin B3 delivered to the body from the substance also has little effect on your blood lipids, according to the British Columbia Drug and Poison Information Centre.

Niaspan, a prescription, time-release form of niacin, dissolves more slowly than regular tablets but more quickly than the nonprescription, time-release form of the vitamin. This form of vitamin B3 positively affects your lipid profile with reduced risk of flushing and isn't as hard on your liver. The downside is that Niaspan is available only by prescription and is the most expensive form of niacin.

Avoid taking niacinamide as an alternative to avoid niacin flush. Although, like niacin, it helps the body convert food into glucose, it does nothing to help your blood lipid profile, according to WebMD.

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Besides taking a time-release form of the supplement, there are a couple of other things you can do to prevent an uncomfortable niacin flush.

Start with a low dose of niacin, such as 100 milligrams, and gradually build up the dose over a period of weeks. Talk to your doctor about the best way to increase your daily intake, such as splitting the daily amount between two or more doses throughout the day. British Columbia Drug and Poison Information Center recommends 100 milligrams twice daily for the first week and doubling the dose each week thereafter until you are taking the full amount prescribed by your doctor.

Always take your niacin pill with food or after eating to prevent nausea and limit the risk of developing a niacin flush. Take a low-dose (81 to 325 milligrams) aspirin a half-hour before your morning niacin tablet.

Do not take niacin to treat high cholesterol or high triglycerides without your doctor's approval. Some medical conditions, such as peptic ulcers, can become aggravated by too much of the vitamin. Conditions typically exacerbated by niacin include allergies, gallbladder problems and low blood pressure. Pregnant people and those taking statins or medications for blood sugar, blood pressure, bleeding or other blood-related medical conditions should not take niacin.