Nicotinic Acid Unit Converter

Nicotinic acid is one of two forms of vitamin B3 (the other being nicotinamide). It is a water-soluble B-complex vitamin that the body uses to build the coenzymes NAD and NADP, which are essential for hundreds of metabolic reactions.

A plasma nicotinic acid test measures the circulating level of this vitamin in your blood. Because nicotinic acid is rapidly absorbed and metabolized, plasma levels are sensitive to recent food intake and supplementation rather than long-term body stores.

The body can also synthesize niacin from the amino acid tryptophan, though the conversion is inefficient: roughly 60 mg of tryptophan yields just 1 mg of niacin.

Nicotinic acid is obtained from dietary sources such as poultry, fish, red meat, peanuts, legumes, and enriched grains. The body also synthesizes it from the amino acid tryptophan via the kynurenine pathway, a conversion that depends on adequate vitamin B6, riboflavin, and iron.