Understanding Nicotinuric Acid: Normal vs Optimal Ranges

?What is Nicotinuric Acid?

Nicotinuric acid is the primary urinary metabolite of nicotinic acid (niacin), formed by glycine conjugation in the kidney. Measuring urinary nicotinuric acid is used to assess niacin intake and metabolism at a population and individual level. It appears in urine alongside N1-methylnicotinamide and 2-pyridone as the main niacin metabolites, and the ratio of these metabolites can indicate the nutritional versus pharmacological niacin intake range.

!Why It Matters

Urinary niacin metabolites, including nicotinuric acid, are the most objective measure of actual niacin intake and absorption — they reflect true bioavailability rather than theoretical dietary intake. In populations at risk for pellagra, measuring nicotinuric acid quantifies the severity of deficiency. During pharmacological niacin therapy, metabolite profiles help distinguish between pharmacological and physiological niacin status.

Reference Ranges

Lab normal ranges may vary between laboratories. Optimal and longevity targets are based on research literature and should be interpreted with your physician.

Symptoms of Imbalance

• Low excretion: niacin deficiency or malabsorption
• Part of pellagra metabolite profile
• High excretion: pharmacological niacin intake or supplementation

How to Improve Your Levels

• 1Increase dietary niacin from food sources to normalise urinary metabolite excretion
• 2Ensure adequate protein (tryptophan) as a niacin precursor
• 3Address malabsorption or bowel conditions that reduce niacin bioavailability

When to Test

Niacin status assessment in nutritional evaluation; pellagra diagnosis; monitoring pharmacological niacin therapy; research and epidemiological dietary studies.

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