Vitamin B3 (Niacin) Health Benefits, Dosages, Food Sources, Side Effects & Interactions

Vitamin B3 is a B-complex vitamin that is also called niacin. Like other B-complex members, vitamin B3 is needed to derive energy from the foods we eat.

All B-complex vitamins help to metabolize carbohydrates into energy, properly utilize fats and proteins, and maintain healthy skin, eyes, and hair. They are also needed for healthy nervous system functioning and liver health. [2]

All cells in humans require adequate vitamin B3 for proper functioning. Niacin is a cofactor for over 200 important enzymes that modulate cellular metabolism. It also has roles in DNA repair, free radical defense and cell signaling. [1]

Niacin is used as a supplement for brain function, arthritis, cardiovascular health, mood enhancement, skin health, headaches, and more. Additionally, clinical research has shown that niacin might be beneficial for lowering cholesterol levels.

This article will discuss the research that exists on the uses and health benefits of vitamin B3 as well as how this compound works in the body, deficiency issues, dosages, supplement information, safety, and side effects.

Niacin

Vitamin B3 Supplement

Heart Health

Blood Lipids

Energy

How It Works:

• Helps maintain healthy cholesterol levels
• Supports proper metabolic functioning
• Promotes heart & nervous system health

Dosage:

Between 100 - 500 mg per day

Safety:

Rated Likely Safe

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How Does Vitamin B3 Work in the Body?

The University of Maryland Medical Center (UMM) states that there are two primary forms of vitamin B3 – niacin (nicotinic acid) and niacinamide (nicotinamide). [2]

According to MedLine Plus, niacin and niacinamide have been studied the most because they are precursors of two important enzymes called NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate). [3]

Both NAD and NADP are important because they are essential to proper metabolic functioning.

They are needed for various processes including ATP (adenosine triphosphate) synthesis, oxidation/reduction reactions, and ADP (adenosine diphosphate) transfer reactions. [4]

According to the UMM, niacin is also needed in the body for the production of stress-resisting hormones and sex hormones. In this capacity, Vitamin B3 helps to stimulate the adrenal glands, decrease systemic swelling, and improve circulation. [4]

All forms of vitamin B3, like all B-complex vitamins in general, are water soluble. They are easily absorbed from the gastrointestinal tract when taken as oral supplements.

This nutrient is not stored in the human body, and therefore needs to be taken in routinely for optimal health. In comparison, fat-soluble vitamins can be stored in the body and do not need to be consumed as regularly in the diet to avoid deficiency.

Individuals can increase their levels of niacin by eating plants and animals that contain it and/or by taking dietary supplements.

Humans are also able to produce vitamin B3 from the amino acid tryptophan, however this conversion is not very efficient. 60 mg of tryptophan are required to produce 1 mg of niacin.

Vitamin B3 Deficiency

In western countries, vitamin B3 deficiency is very rare among people who eat a healthy and varied diet. Deficiency is most common in places where people do not have access to diverse diets and a large portion of the diet is composed of cereal grains or corn.

Some of the most common symptoms of vitamin B3 deficiency include: headache, fatigue, depression, confusion, memory loss, skin problems, and/or diarrhea. [1]

Severe cases of niacin deficiency can cause pellagra, a condition marked by mental disturbances, diarrhea, and poor skin health. This is sometimes referred to as the three Ds: dementia, diarrhea, and dermatitis.

Many times, pellagra has been associated with diets that are excessively based on corn. [4]

According to the Natural Medicines Comprehensive Database (NMCD) pellagra has been virtually eliminated in western countries. It is typically only seen in severe alcoholics, those with chronically poor diets, and those with carcinoid tumors or other conditions that decrease niacin production and/or inhibit tryptophan absorption from the gut. [4]

Vitamin B3 Uses and Health Benefits

According to the NMCD, people take vitamin B3 for a variety of uses including: [4]

• Acne
• Alzheimer’s disease and other forms of age-related cognitive decline
• Anti-aging
• Arthritis
• Attention-Deficit Hyperactivity Disorder (ADHD)
• Cataracts
• Circulation issues
• Depression
• Diabetes
• Diarrhea associated with cholera
• Improving digestion
• Lowering blood lipids
• Memory loss
• Migraines
• Motion sickness
• Vertigo

The NMCD rates vitamin B3 as Likely Effective for pellagra and dyslipidemia.

Dyslipidemia refers to abnormal blood lipid levels, whether high or low. The most common form of dyslipidemia is hyperlipidemia, which is abnormally high levels of lipids in the blood, which can refer to cholesterol or triglycerides.

The NMCD also rates niacin as Possibly Effective for atherosclerosis (hardening of the arteries due to plaque buildup), cholera, HIV/AIDS-related dyslipidemia, and metabolic syndrome.

Some preliminary research has shown promising results using this vitamin supplement for other conditions such as diabetes mellitus, Alzheimer’s disease, ADHD, and osteoporosis but this research is limited.

Research is ongoing concerning vitamin B3’s possible effects on cognitive decline, eye/vision health, various dermatological conditions, migraine headache, depression, motion sickness and alcoholism, ED (erectile dysfunction), kidney failure, high blood pressure (hypertension) and slowing down the aging process. [4]

More clinical research is still needed to determine the therapeutic efficacy of vitamin B3 for any of these and other purposes.

The FDA has approved some specific Vitamin B3 products as prescription medications, typically used for dyslipidemia. These products are typically used in a clinical setting and prescribed by a doctor.

Most niacin products are sold as dietary supplements and are not intended to be used for the prevention or treatment of medical conditions. The FDA does not approved Vitamin B3 supplements as drugs to alleviate or improve health conditions.

Blood Lipid Imbalances and Cardiovascular Health

According to the UMM vitamin B3 has been used since the 1950’s to help reduce elevated blood low density lipoprotein (LDL) cholesterol levels and triglyceride levels. It has also been observed to raise high-density lipoprotein cholesterol (HDL – “good cholesterol”) levels.

According to a 2016 research study from Germany, vitamin B3 can positively alter lipid disorders including:

• Elevated LDL cholesterol
• Elevated lipoprotein(a)
• Elevated non-HDL cholesterol
• Elevated triglycerides
• Reduced HDL cholesterol

According to the researchers, “Niacin may be useful for compliant patients, however possible side effects (flushing, liver damage) and contraindications should be taken into consideration.” [5]

Niacin is also being studied for its possible effects on atherosclerosis (clogged arteries) and heart disease. [2]

The NMCD notes that in one study involving men with existing heart disease, taking vitamin B3 along with colestipol (Colestid) inhibited the progression of atherosclerosis.

Men in this study were observed to experience fewer myocardial infarctions (heart attack), as well as fewer deaths resulting from heart disease, compared to men who took colestipol alone. [4]

In a different study, patients with heart disease decreased their risks of having a first heart attack, or ischemic stroke, by taking vitamin B3 in combination with a statin drug called Zocor (simvastatin). This treatment also resulted in a decreased risk of mortality in these patients. [4]

In one trial, men taking only vitamin B3 reduced their risks of having second heart attacks following an initial myocardial infarction. However, in this study, there did not seem to be any reduced probability for mortality from heart disease. [4]

The evidence for vitamin B3 use in cases of dyslipidemia is substantially positive. It has been rated as Likely Effective by the NMCD for this purpose.

Prescription niacin USP products are FDA-approved for the treatment of dyslipidemia. Niaspan® (niacin extended-release) and Niacor 500 mg tablets are two preparations used in the United States. Laropiprant (Merck & Co., Inc.) sold as Tredaptive is available in Europe.

Vitamin B3 is typically considered a second-line therapy for people who need to primarily lower their LDL cholesterol levels compared to other treatments such as statins. However, it is sometimes used as a first-line treatment in cases where patients with mixed dyslipidemia need to raise their HDL cholesterol levels and lower triglycerides.

The research conducted using niacin for atherosclerosis is quite promising, but rather limited. More research is required to make determinations on the therapeutic efficacy of this nutrient for atherosclerosis, heart disease, and/or other related conditions. [4]

Diabetes

Vitamin B3 has been studied for effects in both type 1 and type 2 diabetes mellitus.

Type 1 is an autoimmune disease that causes the immune system to attack the pancreas and destroy specialized cells that produce insulin. Type 2 is a condition in which the body cannot use insulin properly, resulting in blood sugar dysregulation.

Niacinamide might be able to protect the pancreatic cells that produce insulin. This might decrease the chances of type 1 diabetes developing in children at high risk for it. [7]

However, evidence is mixed. More research is needed to tell if and how niacinamide may help to prevent, delay or otherwise alter type 1 diabetes development. [7]

In type 2 diabetes, vitamin B3 may have both positive and negative effects. This vitamin might help to reduce diabetic complications that stem from excessive cholesterol and fats in the blood.

However, it may also cause blood glucose levels to increase, which is especially risky for those with diabetes. [7]

More research is needed to tell if the risks of vitamin B3 are worth the potential benefits in those with type 2 diabetes.

Those with type 1 or type 2 diabetes should not use this supplement without the advice and supervision of their endocrinologists.

Osteoarthritis

Some preliminary evidence suggests that vitamin B3 in the form of niacinamide may improve symptoms associated with arthritis.

In rats with induced arthritis, vitamin B3 has been injected to reduce arthritis-related redness and swelling.

In one pilot study, taking niacinamide improved joint flexibility and decreased the need for NSAIDs (nonsteroidal anti-inflammatory drugs) compared to placebo. [8] It was concluded that niacinamide improved the overall arthritis impact and pain experienced by patients.

Although this preliminary evidence is promising, only one study has been conducted evaluating the effects on osteoarthritis. More clinical research is needed to confirm whether vitamin B3 can improve symptoms of other bone and joint conditions.

Vitamin B3 Food Sources

Vitamin B3 is found in a variety of foods that are widely consumed in the North American diet. Many foods contain some amounts of this vitamin or its precursors. For most people, getting enough from the diet is not difficult.

You can increase your B3 levels by consuming animal meats, fortified breads and cereals, green leafy vegetables, poultry, fish, and some energy drinks. The Linus Pauling Institute states that other foods with vitamin B3 content include beans, legumes, wheat germ, peanuts, lentils, and coffee.

When possible, it is recommended that vitamin B3, and other nutrients be gained primarily from organic, non-GMO vegetables and fruits. When eating animal products, the best sources are grass-fed, organic meat and dairy products.

If increasing intake from the diet is not possible, there are a variety of vitamin B3 and B-complex supplements available.

Vitamin B3 Supplements

Supplements provide much higher amounts of vitamin B3 than most food sources. If you are deficient in this vitamin or have a medical condition that higher doses might help, then your doctor might advise you to take a B-complex supplement.

B-complex vitamins work together in the body and typically should be taken together. It is not generally advised to supplement one B-complex vitamin without also supplementing other forms.

Some doctors recommend a niacin supplement for patients with high risk factors for heart disease, like high cholesterol levels for instance. B3 might be particularly helpful for those with an intolerance to commonly-prescribed statin drugs.

The NMCD states that there are nearly 7000 dietary supplements that contain vitamin B3 as an ingredient. Always look for third-party verified, cGMP compliant supplements produced by reputable manufacturers.

Always follow dosing instructions on the products you purchase, unless otherwise instructed by your doctor.

High doses of supplemental vitamin B3 can cause side effects and interactions. Always discuss beginning to use dietary supplements like niacin with your doctor to determine whether they are appropriate for you.

Vitamin B3 Dosage Guidelines

The Linus Pauling Institute (LPI) reports the following recommended dietary intake levels for vitamin B3:

• 2 milligrams daily for infants between 0 and 6 months
• 4 mg/day for infants between 7 and 12 months
• 6 mg/day for children between 1 and 3 years
• 8 mg/day for children between 4 and 8 years
• 12 mg/day for children between 9 and 13 years
• 16 mg/day for boys and men 14 years and older
• 14 mg/day for girls and women 14 years and older
• 18 mg/day for pregnant women
• 17 mg/day for women who are breastfeeding [6]

The LPI states that doses higher than those recommended above should be discussed with a medical professional and taken only with medical supervision.

Most dietary supplements that contain this ingredient provide between 100 – 1000 mg of niacin per serving.

A common form of this ingredient found in dietary supplements is Inositol Hexanicotinate or “No-Flush Niacin”. This supplement has been sold in 800 mg serving sizes, yielding 640 mg of Vitamin B3 and 160 mg of inositol.

Certain niacin products have received FDA approval for the treatment of hyperlipidemia. These products typically contain 500 mg of active ingredient per dosage.

Higher dosages have been used in research studies. According to the NMCD, “The most pronounced increases in HDL and decreases in triglycerides occur at 1200-1500 mg/day. Niacin’s greatest effects on LDL occur at 2000-3000 mg/day.”

Taking dosages this high should only be conducted under medical supervision. Using too much niacin can increase the risk of serious adverse reactions.

Vitamin B3 Supplement Side Effects

The Natural Medicines Comprehensive Database has rated vitamin B3 as Likely Safe when used orally and appropriately.

The LPI states that there are no dangers associated with consuming foods that contain vitamin B3. However, dietary supplements, especially at high doses, can cause a variety of adverse effects. Some possible adverse reactions include nausea, vomiting, and liver toxicity.

Many new users of Vitamin B3 supplements experience what is called the “niacin flush”. This reaction has been reported when taking dosages as low as 30 mg per day, but is more common at higher dosages.

This occurs because niacin can cause vasodilation (expanding of blood vessels) near the surface of the skin. This results in blood flowing more freely especially in the face, neck and chest, which can cause flushing as well as an itching sensation.

The sensation is likened to tingling, slight burning, and/or pain. The Niacin flushing reaction goes away on its own, normally within 45 minutes or so.

High doses of supplemental vitamin B3 over time might cause liver damage. Because of this, some doctors are reluctant to prescribe this vitamin for combating high cholesterol in some patients.

There is some concern that doses of vitamin B3 between 3 and 9 grams daily can impair blood glucose modulation. This has been noted in both short-term and long-term usage. Because of this, those with diabetes or prediabetes should not use this supplement without the advice of their endocrinologists.

The UMM states that high doses of supplemental niacin can also cause headache, dizziness, and/or blurred vision. You should discuss possible vitamin B3 side effects with your doctor before deciding to take this supplement.

Vitamin B3 Drug Interactions & Contraindication

Vitamin B3 can interact with a variety of medications, herbs, and dietary supplement. Talk with your doctor and use caution before taking this product in combination with any of the following:

• Antiplatelet/anticoagulant herbs like turmeric, angelica, garlic, danshen, ginger, ginseng and red clover, and others
• Hepatotoxic herbs like borage leaf, DHEA, kava, comfrey, red yeast, pennyroyal oil, and others
• Hypotensive supplements like andrographis, coenzyme Q10, stinging nettle, fish oil, theanine and cat’s claw

It is advised to use caution when taking vitamin B3 supplements along with tryptophan, selenium, vitamin C, vitamin E and/or zinc. These nutrients can affect the production and absorption of niacin in the body.

Vitamin B3 can also alter the effects and side effects of several types of medications. Talk to your doctor before using this supplement with alcohol, allopurinol (Zyloprim), antiplatelet/anticoagulant drugs like clopidogrel (Plavix) and enoxaparin (Lovenox), and antihypertensive drugs like enalapril (Vasotec), valsartan (Diovan), and furosemide (Lasix).

Use caution when combining vitamin B3 with aspirin, bile acid sequestrants, carbamazepine (Tegretol), clonidine (Catapres), and gemfibrozil (Lopid).

The NMCD states that vitamin B3 can interact with several health conditions. Some of these include allergies, coronary artery disease (CAD), unstable angina, Crohn’s disease, and diabetes mellitus.

Vitamin B3 can also cause complications in those with gallbladder disease, gout, kidney disease, liver disease, peptic ulcer disease, and severe hypotension (low blood pressure).

Discontinue use of this supplement at least 2 weeks prior to any scheduled surgeries.

Vitamin B3 is an essential nutrient that the human body required in order to function optimally. It is readily available in numerous foods, and can be taken as a supplement when needed for specific conditions.

If you are interested in taking supplemental Vitamin B3 speak with your doctor to determine whether this supplement is appropriate for you.

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