Niacin (vitamin B3)


The Birds and the B’s: It’s time to have the Talk*

*This is the third of eight articles in our series on B vitamins

The B-complex vitamins belong to the group of vitamins known as the water soluble vitamins. There are technically 8 B-complex vitamins. These include, vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (Niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), Biotin, vitamin B12, and Choline (the unofficial B vitamin).  

The specific function of each of the individual B-complex vitamins varies, yet they all play an important part in energy production. More specifically, all of the B-complex vitamins perform as cofactors for numerous major enzymes in the human body.  Without the presence of these vitamins, many of the enzymes necessary for the metabolism of fat, protein, and carbohydrate would not function properly.

Niacin (vitamin B3)

Niacin, which is also known as vitamin B3, is one of the water soluble vitamins. The water soluble vitamins include all of the B vitamins and vitamin C. The fat soluble vitamins include vitamins A, D, E, and K. Unlike the fat-soluble vitamins, the water soluble vitamins are not stored in the body and must be replenished daily. The water soluble vitamins are also easily destroyed during cooking, especially when food is cooked in water, and during storage. 

 Unlike other vitamins, niacin can be manufactured by the body from the conversion of tryptophan. For this reason, many nutritionists do not consider niacin to be an essential vitamin as long as the diet includes ample amounts of tryptophan.

Why do we need niacin?

The purpose of niacin in the body is to function as a component of the enzymes nicotinanimde adenine dinucleotide (NAD) and nicotinanimde adenine dinucleotide (NADP). These two enzymes are extremely important because they play roles in over 50 different chemical reactions in the body. NAD and NADP are essential for the proper metabolism of fat, cholesterol, and carbohydrate, as well as energy production, and the production of many hormones in the body such as sex and adrenal hormones. Without niacin, NAD and NADP would not be able to perform correctly.

History of niacin

Pellagra is the disease that is the result of severe niacin deficiency. Pellagra was quite common in Spain and Italy during the eighteenth century. Niacin was eventually discovered as the result of an intensive search for the cure for Pellagra.

Niacin deficiency

A severe deficiency of niacin and tryptophan can result in Pellagra. Pellagra is distinguished by what is referred to as the “three Ds”: dermatitis, dementia, and diarrhea. When pellagra is present, the skin becomes inflamed and appears to be scaly or cracked, the brain ceases to function properly; which leads to dementia, and the production of the mucous lining of the gastrointestinal tract becomes impaired; which results in diarrhea. An intake of at least 18mg of niacin per day is suggested by most authorities in order to prevent niacin deficiency.

Vegan raw food sources of niacin

 In general, legumes and whole grains, with the exception of corn, are good sources for niacin. Here are some other foods that provide a source for niacin:



Brown Rice


Pine nuts

Red chili peppers

Sesame Seeds

Split peas

Sunflower Seeds

Wild rice

Whole wheat

Niacin toxicity

Large doses of niacin are occasionally used by physicians to treat schizophrenia. However, high doses of niacin in the form of supplementation should not be consumed without consulting a physician, as it can result in glucose intolerance, peptic ulcers, and liver problems. 

 Written by: Angela Coate-Hermes

Copyright 2009 All rights reserved

These statements have not been evaluated by the food and drug administration.  The preceding information and/or products are for educational purposes only and are not meant to diagnose, prescribe, or treat illness. Please consult your doctor before making any changes or before starting ANY exercise or nutritional supplement program or before using this information or any product during pregnancy or if you have a serious medical condition.  


Marz, Russell. Medical Nutrition from Marz. Portland, OR: Oni-press, 1999.

Murray, Michael and Joseph Pizzorno. The Encyclopedia of healing Foods. New York: Atria Books, 2005.