Test Catalog

Test Id : VITB3

Vitamin B3 and Metabolites, Plasma

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assisting in the diagnosis of suspected vitamin B3 deficiency or toxicity


May be useful in determining response to therapy

Method Name
A short description of the method used to perform the test

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Vitamin B3 and Metabolites, P

Lists additional common names for a test, as an aid in searching


Vitamin B3

Nicotinic Acid


Nicotinuric Acid


Specimen Type
Describes the specimen type validated for testing

Plasma EDTA

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation: Fasting 4 to 8 hours preferred

Supplies: Sarstedt 5 mL Aliquot Tube (T914)

Collection Container/Tube:

Preferred: Lavender top (K2 EDTA)

Acceptable: K3 EDTA

Submission Container/Tube: Plastic vial

Specimen Volume: 1.5 mL

Collection Instructions: Centrifuge and aliquot plasma into a plastic vial within 2 hours of collection.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.75 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Plasma EDTA Refrigerated (preferred) 28 days
Frozen 28 days
Ambient 21 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assisting in the diagnosis of suspected vitamin B3 deficiency or toxicity


May be useful in determining response to therapy

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Vitamin B3 is the term used for a group of closely related water-soluble pyridine derivatives, primarily derived from tryptophan. Niacin (also known as nicotinic acid) is converted to nicotinamide, which can also be synthesized directly from tryptophan. Nicotinamide serves as the precursor of nicotinamide-adenine dinucleotide (NAD) and NAD phosphate (NADP), essential coenzymes for numerous dehydrogenases. Many of these enzymes play a role in energy release from carbohydrates and fats, but numerous other pathways are also NAD/NADP dependent, ranging from intra- and inter-cell signaling, to DNA repair, to fatty acid-, cholesterol- and steroid hormone synthesis, and many other vital biochemical functions.


Nicotinuric acid is a major inactive metabolite of niacin and nicotinamide.


Vitamin B3 deficiency most severely impacts tissues with high energy requirements, or high turnover. Thus, skin, the gastrointestinal tract, and the brain are primarily affected, but the function of numerous other organ systems, such as bone marrow and heart, might also be impaired. Severe vitamin B3 deficiency manifests as a distinct clinical syndrome, called pellagra, which is clinically characterized by the "3Ds": dermatitis, diarrhea, and dementia; if untreated, it will result in death.


The onset of deficiency symptoms is subacute or chronic.


The most common cause of vitamin B3 deficiency is inadequate dietary intake of niacin or tryptophan. At-risk populations are older adults, those with limited income, and those who are malnourished or suffer from malabsorption. Malnourished individuals with severe chronic alcoholism are at particularly high risk, as high alcohol intake impairs absorption of niacin and tryptophan as well as further downstream liver metabolism to bioactive of vitamin B3 compounds.


Liver disease in general is also a risk factor, as nicotinamide is derived in the liver from tryptophan. This process requires vitamins B6, B2, and iron, so deficiencies of any of these factors might also predispose the individual to vitamin B3 deficiency.


Issues that impact the availability of tryptophan for vitamin B3 synthesis can also lead to deficiency. Examples include:

-Hartnup disease, a hereditary disorder that reduces tryptophan absorption

-Carcinoid syndrome, a gastro-entero-pancreatic neuroendocrine tumor disorder that results in serotonin overproduction, with the majority of available tryptophan being channeled into serotonin synthesis

-Various drugs (eg, isoniazid, chloramphenicol, fluorouracil, mercaptopurine)


In most cases, vitamin B3 supplementation should result in a cure, even if the deficiency has progressed to the state of pellagra.


Vitamin B3 toxicity is much less common than deficiency. Its occurrence is essentially limited to individuals who consume vitamin B3 supplements in extremely excessive doses, or to patients who are prescribed niacin for treatment of hypercholesterolemia, as the doses used in this setting are very high. Common symptoms are flushing, itching, dizziness, tachycardia, nausea and vomiting, diarrhea, and gout. Rarely liver damage or stroke has been observed. The onset of symptoms is acute or subacute.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Nicotinic Acid (Niacin) Cutoff: <5.0 ng/mL

Nicotinamide: 5.0-48.0 ng/mL

Nicotinuric Acid Cutoff: <5.0 ng/mL

Provides information to assist in interpretation of the test results

Nicotinamide concentrations below the established reference range indicate a deficiency.


Niacin or nicotinamide concentrations that exceed the upper reference range substantially suggest potential toxicity in patients with excessive supplement intake or under niacin treatment for hypercholesterinemia.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Testing of nonfasting specimens can result in elevated plasma vitamin B3 concentrations, particularly in patients with dietary supplement use or patients on niacin treatment.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Delgado-Sanchez L, Godkar D, Niranjan S: Pellagra: rekindling of an old flame. Am J Ther. 2008 Mar-Apr;15(2):173-175. doi: 110.1097/MJT.1090b1013e31815ae31309

2. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA): A Scientific opinion on dietary reference values for niacin. EFSA Journal. 2014;12(7):3759. doi: 10.2903/j.efsa.2014.3759

3. Expert Group on Vitamins and Minerals: Safe Upper Levels for Vitamins and Minerals. Food Standard Agency; 2003:1-361. Accessed January 18, 2022. Available at https://cot.food.gov.uk/sites/default/files/vitmin2003.pdf

4. Fu CS, Swendseid ME, Jacob RA, McKee RW: Biochemical markers for assessment of niacin status in young men: Levels of erythrocyte niacin coenzymes and plasma tryptophan. J Nutr. 1989 Dec;119(12):1949-1955

5. Powers HJ: Current knowledge concerning optimum nutritional status of riboflavin, niacin and pyridoxine. Proc Nutr Soc. 1999 May;58(2):435-440

6. Shah GM, Shah RG, Veillette H, et al: Biochemical assessment of niacin deficiency among carcinoid cancer patients. Am J Gastroenterol. 2005 Oct;100(10): 2307-2314. doi: 2310.1111/j.1572-0241.2005.00268.x

7. Sun WP, Zhai MZ, Li D, et al: Comparison of the effects of nicotinic acid and nicotinamide degradation on plasma betaine and choline levels. Clin Nutr. 2017 Aug;36(4):1136-1142

Method Description
Describes how the test is performed and provides a method-specific reference

Vitamin B3 components (nicotinic acid/niacin, nicotinamide, nicotinuric acid) are extracted from plasma specimens with internal standard and then analyzed by liquid chromatography-tandem mass spectrometry.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Tuesday, Thursday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

2 to 4 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

2 weeks

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their Regional Manager. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
VITB3 Vitamin B3 and Metabolites, P In Process
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
609493 Nicotinic Acid (Niacin) 18244-4
609494 Nicotinamide 56961-6
609495 Nicotinuric Acid 72306-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
New Test 2022-04-21