What is Vitamin B3 and What Does It Do?

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What is Vitamin B3 and What Does It Do?

What is niacin, and what does it do?

Niacin is a water-soluble B vitamin that is also known as vitamin B3, nicotinamide, or nicotinic acid. Niacin assists in the proper functioning of the nervous and digestive system, maintaining healthy skin, and conversion of food to energy.

How much niacin do I need to consume?

There is insufficient information to establish an RDA for niacin for infants. In this case, an Adequate Intake (AI) has been established:
Age Males and Females
0 to 6 months 2 mg
7 to 12 months 4 mg
The Recommended Dietary Allowance (RDA) for niacin is:
Age Males Females Pregnancy Lactation
1 to 3 years 6 mg 6 mg N/A N/A
4 to 8 years 8 mg 8 mg N/A N/A
9 to 13 years 12 mg 12 mg N/A N/A
14 to 18 years 16 mg 14 mg 18 mg 17 mg
19+ years 16 mg 14 mg 18 mg 17 mg

What are the sources of niacin?

Niacin is found in animal products, nuts, green vegetables, legumes, and enriched and fortified cereals.
Food Amount Niacin Content
Bagel 4″ 3.06 mg
Barley, pearled, cooked 1 cup 3.24 mg
Beans, kidney, red, boiled 1 cup 1.02 mg
Beef, eye of round, roasted 3 oz 5.24 mg
Bread, rye 1 slice 1.22 mg
Carrots, cooked 1 cup 1.01 mg
Cereal, fortified 1 cup 5.00 mg
Ham, sliced, extra lean 2 slices 2.23 mg
Mango, raw 1 mango 1.21 mg
Milk, nonfat 1 cup 0.23 mg
Peanut butter, smooth 1 tablespoon 2.14 mg
Peas, frozen, cooked 1 cup 2.37 mg
Potato, no skin 1 cup 2.05 mg
Rice, brown, long-grain, cooked 1 cup 2.98 mg
Soybeans, cooked 1 cup 2.25 mg
Tomato, canned, sauce 1 cup 2.39 mg

Do I need to take a niacin supplement?

A well-balanced diet can provide enough niacin to reach your needs. When you have a medical need, a deficiency, or an inadequate diet, you should consult with your physician before taking a niacin supplement. High doses must be prescribed by a physician since niacin can be used as a drug (see below). Niacin supplements come in several forms: niacin, inositol hexaniacinate, and niacinamide

What happens if I don’t have enough niacin?

Niacin was discovered in low-income populations where corn products were the primary source of calories, and the disease pellagra was occurring. The symptoms of pellagra are known as the four Ds: dermatitis, diarrhea, dementia, and death. Pellagra occurs at the late stage of niacin deficiency. Niacin deficiency symptoms will involve the digestive system (diarrhea, vomiting, and bright red tongue), the skin (thick, scaly skin and a darkly pigmented rash that develops symmetrically in areas exposed to sunlight), and the nervous system (fatigue, depression, headache, apathy, disorientation, and memory loss).

Is there such a thing as too much niacin?

Doses much higher than the ULs are used medically to improve cholesterol levels. High doses of niacin can cause dangerous liver inflammation, peptic ulcers, and skin rashes. “Niacin flushing” is a side effect that causes redness, itching, and burning and can occur within 10 to 15 minutes after taking it and can last up to one hour. Research has shown that there are conditions that make people susceptible to these symptoms, including diabetes mellitus, gout, cardiac arrhythmias, hepatic dysfunction or a history of liver disease, migraine headaches, alcoholism, and inflammatory bowel disease. These conditions may not be protected by the UL that has been set for the general population, so extreme caution needs to be used when taking niacin supplements. For everyone, the only time that high doses of niacin should be taken would be under the supervision of your physician. The Tolerable Upper Limit (UL) for niacin is:

Age Males and Females Pregnancy Lactation
1 to 3 years 10 mg/day N/A N/A
4 to 8 years 15 mg/day N/A N/A
9 to 13 years 20 mg/day N/A N/A
14 to 18 years 30 mg/day 30 mg/day 30 mg/day
19+ years 30 mg/day 35 mg/day 35 mg/day

The Most Common Niacin Side Effects

If you’re eating foods rich in niacin, the chances that you’ll experience side effects are very slim. However, it’s possible to experience niacin side effects when taking supplements, especially if you have high doses. The following niacin side effects seem to occur most often in people who are taking high dose supplements and who have pre-known medical conditions:

  • Nausea or vomiting
  • Skin reactions, rashes
  • Headaches
  • Dizziness
  • Allergic reactions: Niacin supplements can cause allergies because some contain histamines, chemicals substances that can trigger allergic symptoms to be released
  • Heart problems: High doses of niacin may increase the risk of irregular heartbeats
  • Diabetes: Niacin and niacinamide might increase blood sugar. People with diabetes who take niacin or niacinamide should check their blood sugar carefully.
  • Worsened gallbladder or liver disease symptoms
  • Aggravated gout symptoms.
  • Low blood pressure
  • Stomach or intestinal ulcers
  • Problems after surgery controlling blood sugar levels
Herbal Guide Staff


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