Other names: Niacin / Nicotinamide / Nicotinic Acid
Niacin (nicotinic acid) is a water-soluble vitamin that is also referred to as vitamin B3.
Nicotinamide (nicotinic acid amide) is the derivative of niacin that is incorporated into the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). The nicotinamide moiety of NAD and NADP serves as an electron acceptor or donor in biological oxidation-reduction (redox) reactions catalyzed by several hundred different enzymes. NAD serves as the cofactor for enzymes that break down (catabolize) carbohydrates, fats, proteins, and alcohol while NADP supports biosynthetic (anabolic) reactions, including the synthesis of all macromolecules, such as fatty acids and cholesterol.
Nicotinamide has also been shown to serve as a cofactor in adenosine diphosphate (ADP)-ribose transfer reactions that play an integral part in deoxyribonucleic acid (DNA) repair calcium mobilization.
Studies of cultured cells and animal models suggest that ADP-ribose polymer-mediated DNA repair and cyclic ADP-ribose-mediated cell-signaling pathway may play a role in cancer prevention.
Both nicotinic acid and nicotinamide are absorbed from the normal diet. Nicotinamide is the form of vitamin B3 that is commonly found in nutritional supplements and used to fortify foods.
Nicotinic acid is available both over the counter and with a prescription as a cholesterol-lowering agent.
Other reference ranges:
- Nicotinic acid: 0.0−5.0 ng/mL
- Nicotinamide: 5.2−72.1 ng/mL
A person who lacks vitamin B-3 may experience:
- a pigmented rash on skin that is exposed to the sun
- rough appearance to the skin
- bright red tongue
- fatigue or apathy
- vomiting, constipation, and diarrhea
- circulatory problems
- depression
- headache
- memory loss
- in severe cases, hallucinations
Niacin deficiency can result from inadequate dietary intake of niacin and/or the amino acid tryptophan. Tryptophan, obtained from the breakdown of dietary protein, can be converted to nicotinamide by liver enzymes that require vitamin B6, riboflavin, and iron. Deficiencies of these constituents can contribute to the development of niacin deficiency. Hartnup's disease, a hereditary disorder that reduces tryptophan absorption, can lead to niacin deficiency. Carcinoid syndrome diverts tryptophan to the increased production of serotonin and can reduce the production of nicotinamide. Prolonged treatment with isoniazid has also been associated with niacin deficiency.
Niacin deficiency can affect the skin, digestive system, and the nervous system. Severe niacin deficiency, referred to as pellagra, has been associated with the "four Ds": dermatitis, diarrhea, dementia, and ultimately death. Pellagra dermatitis is characterized by a thick, scaly, darkly pigmented rash that develops symmetrically in areas exposed to sunlight. Digestive system symptoms include vomiting, constipation or diarrhea, and a bright red tongue. Pellagra can also cause neurologic symptoms, including apathy, fatigue, depression, headache, disorientation, and memory loss.
Understand and improve your laboratory results with our health dashboard.
Upload your lab reports and get interpretation today.
Our technology helps to understand, combine, track, organize, and act on your medical lab test results.
The amount of vitamin B-3 found in food does not cause side effects. However, taking high doses of vitamin B-3 as a supplement can result in adverse effects.
These include:
- flushed or itchy skin
- nausea
- vomiting
- constipation
- headache
- rash
- dizziness
Excess vitamin B-3 can also:
- reduce glucose tolerance and insulin resistance
- trigger an attack in people with gout
- result in eye problems
- lead to gastrointestinal problems
- increase the risk of liver damage
- lower blood pressure, leading to a loss of balance and risk of falls
Interpret Your Lab Results
Upload your lab report and we’ll interpret and provide you with recomendations today.
Get Started
Get Started With Our Personal Plan
Advanced Plan
Unlimited Plan
Are You a Health Professional?
Get started with our professional plan
Welcome to Healthmatters Pro.
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more
Pro Plan
for health professionals
$45 per month
At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.
Antiparietal Cell Antibody, Calcitriol (1,25 di-OH Vit D), Copper, Pl, Intrinsic Factor Antibodies (Serum), Intrinsic Factor Blocking Antibody, Manganese, Methylmalonic Acid, Serum, Nicotinamide, Nicotinic Acid, Phosphate (Phosphorus), Vitamin A, Vitamin B1 (Thiamine), Vitamin B12, Vitamin B2 (Riboflavin), Plasma, Vitamin B2, Whole Blood, Vitamin B3 (Niacin), Vitamin B6, Vitamin B9 (Folate), Vitamin C, Vitamin D, 25-Hydroxy, Vitamin E (Tocopherol), Vitamin K, Zinc, RBC
