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Vitamin B3 : 91029
MessageCrtical frozen.
Test Code
VITB3Q or 91029
Alias/See Also
Niacin
CPT Codes
84591
Includes
Nicotinamide and Nicotinic Acid
Instructions
Preferred Specimen
1 mL frozen serum collected in a red-top tube (no gel) - protected from light
Alternative Specimen
Frozen plasma collected in a light protected EDTA (lavender-top) tube
Minimum Volume
0.5 mL
1 mL frozen serum collected in a red-top tube (no gel) - protected from light
Alternative Specimen
Frozen plasma collected in a light protected EDTA (lavender-top) tube
Minimum Volume
0.5 mL
Transport Container
Centrifuge tube as soon as possible and pour serum or plasma into an amber transport tube (preferred) or a transport tube wrapped in aluminum foil to protect from light or place in an amber bag. Freeze immediately.
Transport Temperature
Frozen.
Specimen Stability
Ambient: Unacceptable; Refrigerated: Unacceptable; Frozen: 30 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Serum separator tube (SST)
Methodology
Chromatography/Mass Spectrometry
Setup Schedule
Tuesday & Thursday & Saturday
Report Available
2-4 days (From receipt at performing laboratory)
Reference Range
Nicotinic Acid
Due to the large variability in the metabolism of nicotinic acid, the dosing preparation used (immediate-release vs. extended release), and the mg doses used, the serum concentrations may range from <20 ng/mL to about 30,000 ng/mL. After oral administration of an immediate-release tablet, peak plasma concentrations occur in 4 to 5 hours. The plasma half-life of nicotinic acid is about one hour. In one study, fasting plasma concentrations were reported to be <20 ng/mL. In another study, it was reported that the administration of a single 1000 mg extended-release tablet resulted in mean nicotinic acid concentrations of <50 ng/mL.
Nicotinamide
Nicotinamide is a metabolite of nicotinic acid. Due to the large variability in the metabolism of nicotinic acid, plasma concentrations of this metabolite are variable. In one study, fasting plasma concentrations were reported to be approximately 40 ng/mL. In another study it was reported that the administration of single 1000 mg of extended-release tablet of nicotinic acid resulted in a mean peak nicotinamide concentration of 400 ng/mL between 5 and 10 hours post dose, decreasing to about 100 ng/mL by 16 hours post dose.
Due to the large variability in the metabolism of nicotinic acid, the dosing preparation used (immediate-release vs. extended release), and the mg doses used, the serum concentrations may range from <20 ng/mL to about 30,000 ng/mL. After oral administration of an immediate-release tablet, peak plasma concentrations occur in 4 to 5 hours. The plasma half-life of nicotinic acid is about one hour. In one study, fasting plasma concentrations were reported to be <20 ng/mL. In another study, it was reported that the administration of a single 1000 mg extended-release tablet resulted in mean nicotinic acid concentrations of <50 ng/mL.
Nicotinamide
Nicotinamide is a metabolite of nicotinic acid. Due to the large variability in the metabolism of nicotinic acid, plasma concentrations of this metabolite are variable. In one study, fasting plasma concentrations were reported to be approximately 40 ng/mL. In another study it was reported that the administration of single 1000 mg of extended-release tablet of nicotinic acid resulted in a mean peak nicotinamide concentration of 400 ng/mL between 5 and 10 hours post dose, decreasing to about 100 ng/mL by 16 hours post dose.
Clinical Significance
Nicotinic Acid occurs naturally in plants and animals and is also added to many foods as a vitamin supplement.
Performing Laboratory
Quest Diagnostics
