Niacin (Vitamin B3) Serum Concentration

Your healthcare provider may order this test if they suspect you are not getting enough niacin (vitamin B3) in your diet or if you have symptoms such as skin problems, digestive issues, fatigue, or memory difficulties. It may also be used to check your overall nutritional status or to monitor conditions that make it hard for your body to absorb nutrients.

Your healthcare provider may order this test if you have symptoms of niacin deficiency, such as fatigue, skin problems, or digestive issues. It may also be checked in people with certain metabolic disorders, liver disease, or if you’re taking medications that affect niacin levels. Rarely, it could be part of a broader nutritional assessment.

Before the test, your provider will explain the procedure and answer any questions you have. You may be asked to fast for several hours beforehand, and you should tell your care team about all medicines, vitamins, and supplements you take, especially niacin supplements, since they can affect the results.

No special preparation is usually needed. You may be asked to fast for a few hours before the test, but always follow your provider’s instructions. Bring any medications you’re taking, as some may influence results.

A healthcare professional will clean a spot on your arm, wrap an elastic band around your upper arm, and draw a small sample of blood from a vein using a thin needle. You may feel a quick sting or pinch. The sample is then sent to a laboratory to measure the amount of niacin in your blood, and the whole process usually takes only a few minutes.

A blood sample is drawn from a vein in your arm by a healthcare professional. The blood is then sent to a lab for analysis using an immunoassay method to measure niacin concentration.

Your results will show whether the amount of niacin in your blood falls within the normal range. Levels that are too low may point to a dietary deficiency, while high levels are uncommon but can occur with excessive supplement use. Your provider will review your results along with your symptoms, medical history, and other tests before making a diagnosis or recommending treatment.

Results are typically reported as a mass concentration in micrograms per deciliter (mcg/dL). While reference ranges vary by lab, low levels may indicate deficiency, while very high levels could signal conditions like niacin toxicity or certain metabolic disorders.