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Niacin

Niacin is a type of B vitamin. It is water-soluble vitamin. It is not stored in the body. Water-soluble vitamins dissolve in water. Leftover amounts of the vitamin leave the body through the urine. The body keeps a small reserve of these vitamins. They have to be taken on a regular basis to maintain the reserve.

Function

Niacin helps the digestive system, skin, and nerves to function. It is also important for changing food to energy.

Food Sources

Niacin (also known as vitamin B3) is found in:

  • Milk
  • Eggs
  • Enriched breads and cereals
  • Rice
  • Fish
  • Lean meats
  • Legumes
  • Peanuts
  • Poultry

NIACIN AND HEART DISEASE

For many years, doses of 1 to 3 grams of nicotinic acid per day has been used as a treatment for high blood cholesterol.

Niacin can help in increasing level of good cholesterol (HDL cholesterol) in the blood. It can also bring down the amount of unhealthy fat in the blood. Always talk to your health care provider before starting any supplements.

Side Effects

DEFICIENCY:

A deficiency of niacin causes pellagra. The symptoms include:

  • Digestive problems
  • Inflamed skin
  • Poor mental function

HIGH INTAKE:

Too much of niacin can cause:

When given as a treatment to people with high cholesterol, niacin supplements can cause “flushing.” It is a feeling of warmth, redness, itching or tingling of the face, neck, arms or upper chest.

To prevent flushing, do not drink hot beverages or alcohol with niacin.

New forms of niacin supplement have less side effects. Nicotinamide does not cause these side effects.

Recommendations

REFERENCE INTAKES

Recommendations for niacin and other nutrients are provided in the Dietary Reference Intakes (DRIs), which are developed by the Food and Nutrition Board at the Institute of Medicine. DRI is the term for a set of reference values that are used to plan and assess the nutrient intakes of healthy people. These values, which vary by age and gender, include:

  • Recommended Dietary Allowance (RDA): average daily level of intake that is enough to meet the nutrient requirements of nearly all (97% to 98%) healthy people.
  • Adequate Intake (AI): when there is not enough evidence to develop an RDA, the AI is set at a level that is thought to ensure enough nutrition.

Dietary Reference Intakes for Niacin:

Infants

  • 0 to 6 months: 2* milligrams per day (mg/day)
  • 7 to 12 months: 4* mg/day

*Adequate Intake (AI)

Children (RDA)

  • 1 to 3 years: 6 mg/day
  • 4 to 8 years: 8 mg/day
  • 9 to 13 years: 12 mg/day

Adolescents and Adults (RDA)

  • Males age 14 and older: 16 mg/day
  • Females age 14 and older: 14 mg/day, 18 mg/day during pregnancy, 17 mg/day during lactation

Specific recommendations depend on age, gender, and other factors (such as pregnancy). Women who are pregnant or breastfeeding need higher amounts. Ask your provider which amount is best for you.

The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods.

Alternative Names

Nicotinic acid; Vitamin B3

References

Mason JB. Vitamins, trace minerals, and other micronutrients. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 218.

Salwen MJ. Vitamins and trace elements. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 26.

Review Date 2/2/2019

Updated by: Emily Wax, RD, CNSC, University of Virginia Health System, Charlottesville, VA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.