Vitamin B3 Niacin

Vitamin B3 Niacin - Niacinamide

Vitamin B3 Niacin uses - warnings - foods -interactions

Vitamin B3 consists of niacin and niacinamide. B3 is found in many foods and is often added to supplements in combination with other B vitamins. Besides helping to convert carbohydrates into glucose (fuel) to produce energy, niacin helps the body to create various sex and stress related hormones located in the adrenal glands. It also improves circulation and suppresses inflammation.

Where do humans get B3 Niacin?

Through proper diet, humans get their B3 from eating fish, milk, eggs, green vegetables, cereal grains and yeast. There is also a wide variety of niacin-enriched mushrooms. The body naturally produces niacin from tryptophan, which is found in protein rich foods.

The best food sources of vitamin B3 are beets, brewer's yeast, beef liver, beef kidney, salmon, swordfish, tuna, sunflower seeds and peanuts.

What are its uses?

Niacin is taken to combat vitamin B3 deficiency and related conditions such as pellagra. Pellagra is a condition with the symptoms of cracked, scaly skin, dementia and diarrhea. Additionally, it is used to treat schizophrenia, drug induced hallucinations, Alzheimer’s disease and other age related cognitive disorders, chronic brain syndrome, motion sickness, alcohol dependence, muscle spasms, blood vessel swelling linked with skin lesions, and fluid collection (edema). There is good evidence that niacin is safe and effective for treating high cholesterol levels.

People take oral doses of niacin for treating acne, leprosy, attention deficit-hyperactivity disorder (ADHD), preventing premenstrual headache, improving circulation and digestion, protecting against toxins and pollutants, lowering blood pressure, promoting relaxation, improving orgasms, cataract prevention, and reducing the effects of aging and arthritis.

Other afflictions that niacin appears to be effective treating are hardening of the arteries, diarrhea from cholera, type 1&2 diabetes, osteoarthritis, and preventing cataracts.

What are the interaction precautions of Niacin?

  • Alcohol can cause flushing and itchiness to worsen and possibly increase liver damage.
  • Taking niacin while taking Zyloprim (Allopurinol) for gout can potentially decrease the effectiveness of Zyloprim and worsen gout.
  • Taking niacin with clonidine can lower blood pressure to dangerous levels.
  • Medications for diabetes with long-term use of niacin might increase blood sugar, thus decreasing the effectiveness of diabetes medications. Monitor your blood when taking both together; your diabetes dose might need changing.
  • Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, repaglinide (Prandin), chlorpropamide (Diabinese), pioglitazone (Actos), rosiglitazone (Avandia), metformin (Glucophage), nateglinide (Starlix), glipizide (Glucotrol), tolbutamide (Orinase), and others.
  • Anti-seizure medications such as 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.
  • Niacin can make the effects of medications taken to lower blood pressure stronger and potentially lead to low blood pressure.
  • 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.
  • Isoniazid INH, a medication used to treat tuberculosis, may cause a niacin deficiency.
  • Using nicotine patches with niacin may worsen or increase the risk of flushing associated with niacin.

These medications below may lower levels of niacin in the body.

  • Azathioprine (Imuran)
  • Chloramphenicol (Chloromycetin)
  • Cycloserine (Seromycin)
  • Fluorouracil
  • Levodopa and carbidopa
  • Mercaptopurine (Purinethol)

Herbs and Dietary Supplement Interactions

Niacin may increase the risk of bleeding when taken with herbs and supplements that are thought to increase the risk of bleeding. Known cases are associated with Gingko biloba and lesser with garlic and saw palmetto.

Niacin may increase blood sugar levels. Caution is advised when using herbs or supplements that may alter blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.

Niacin may cause low blood pressure. Caution is advised in people taking herbs or supplements that lower blood pressure.

Niacin may interfere with the way the body processes certain herbs or supplements using the liver's "cytochrome P450" enzyme system. As a result, the levels of other herbs or supplements may be altered in the blood. It may also alter the effects that other herbs or supplements possibly have on the P450 system.

Niacin may also interact with herbs and supplements used for birth control, herbs and supplements used for seizures, inositol hexanicotinate, kava, minerals, pantothenic acid, phytoestrogens, phytoprogestins, salicylate-containing herbs, sitosterols, sorghum, thyroid hormones, tryptophan, vitamins E, A, and B6, and zinc sulfate.

Amino acids, androgens, antibacterials, antigout herbs and supplements, antihistamines, antioxidants, antithyroid herbs and supplements, cholesterol-lowering herbs and supplements, chromium, coffee, ganglionic blocking herbs and supplements, grape seed, herbs and supplements for the heart, herbs and supplements that widen blood vessels, herbs and supplements used for the liver.

Before undertaking B3 supplementation, consult your healthcare professional and trained homeopathic council for recommendations and safety precautions.

Because of the moderate interaction possibilities, anyone taking medications or herbal supplements should consult with their prescribing doctors before undertaking supplementation.



Inform your doctor if you have previously had any unusual or allergic reaction to vitamin B3, niacinamide or other medicines. Follow your healthcare professional’s instructions for safely taking the supplement.

People with known allergy or sensitivity to niacin, niacinamide, or products containing one or both of these products should avoid using.

Rarely, anaphylactic shock has been described after giving niacin by mouth or injecting it into the vein. Anaphylactic shock is a severe reaction.

Side Effects and Warnings

High doses (50 mg or more) of niacin can cause side effects and 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.

Stop taking niacin approximately 2 weeks before any scheduled surgeries.

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.

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 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.

Pregnancy and Breastfeeding

Niacin has been deemed likely to be 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.


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.

Recommended Daily Allowance (RDA) for niacin in the diet of healthy individuals are as follows.

Infants’ birth to 6 months, 2 mg

Infants 7 months to 1 year, 4 mg

Children, 1 to 3 years, 6 mg

Children, 4 to 8 years, 8 mg

Children 9 to 13 years, 12 mg

Boys 14 to 18 years, 16 mg, Girls 14 to 18 years, 14 mg

Adult Men, 19 years and older, 16 mg

Women 19 years and older, 14 mg

Pregnant women, 18 mg

Breastfeeding women, 17 mg


Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not refrigerate. Keep from freezing.

Store the dietary supplement in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Time to SHOP for B12 Vitamins

Disclaimer: The information contained in this website is only for general interest and informational purposes, and is in no way meant to be used to diagnose or prescribe medication or supplementation of any kind to treat any illnesses or symptoms of illnesses. The treatment of illnesses and symptoms mentioned in this website should only be performed in consultation with your physician. In addition, the use, administration and discontinuation of use, of any vitamin supplements purchased on this website should be performed only under the guidance of your physician. Copyright © 2023 B12 Vitamin Store, Inc. All rights reserved.