Niacin vs. Nicotinic Acid

What's the Difference?

Niacin and nicotinic acid are two terms often used interchangeably to refer to the same compound, vitamin B3. Niacin is the generic term used to describe both nicotinic acid and its amide form, niacinamide. However, when specifically referring to nicotinic acid, it is often called niacin or vitamin B3. Nicotinic acid is an essential nutrient that plays a crucial role in energy metabolism and the maintenance of a healthy nervous system. It is commonly found in various food sources and is also available as a dietary supplement. Overall, niacin and nicotinic acid are essentially the same compound, with nicotinic acid being the specific form of niacin that is commonly referred to.


AttributeNiacinNicotinic Acid
Chemical NameNicotinic acidNicotinic acid
Other NamesVitamin B3, NicotinamideVitamin B3, Niacinamide
Chemical FormulaC6H5NO2C6H5NO2
SolubilitySoluble in waterSoluble in water
FunctionEssential for energy production, DNA repair, and cell signalingEssential for energy production, DNA repair, and cell signaling
Food SourcesMeat, fish, poultry, legumes, grains, nutsMeat, fish, poultry, legumes, grains, nuts
Deficiency SymptomsPellagra (skin rashes, digestive issues, mental impairment)Pellagra (skin rashes, digestive issues, mental impairment)
Recommended Daily IntakeMen: 16 mg, Women: 14 mgMen: 16 mg, Women: 14 mg
Supplement FormTablets, capsules, liquidTablets, capsules, liquid

Further Detail


Niacin and nicotinic acid are two terms often used interchangeably to refer to the same compound, vitamin B3. However, there are subtle differences between the two that are worth exploring. In this article, we will delve into the attributes of niacin and nicotinic acid, highlighting their similarities and differences, and shedding light on their various applications and benefits.

Chemical Structure

Niacin and nicotinic acid share the same chemical formula, C6H5NO2, and are both derived from the heterocyclic compound pyridine. They differ in their molecular structure, with niacin featuring a carboxyl group (-COOH) and a primary amine group (-NH2), while nicotinic acid solely contains the carboxyl group. This structural variation leads to differences in their physiological effects and applications.

Metabolism and Bioavailability

When consumed, both niacin and nicotinic acid undergo metabolic processes in the body to be converted into their active forms, nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). However, nicotinic acid requires an additional step in the liver to be converted into its active form, whereas niacin can be directly converted in other tissues. This difference in metabolism affects their bioavailability and the rate at which they exert their effects.

Therapeutic Uses

Niacin and nicotinic acid have been widely used for their therapeutic properties. Niacin, in the form of nicotinamide, is commonly used in dermatology for its anti-inflammatory effects and its role in maintaining healthy skin. It is also an essential component of various enzyme systems involved in energy metabolism. On the other hand, nicotinic acid is primarily used in the treatment of dyslipidemia, as it has been shown to effectively lower triglyceride and LDL cholesterol levels while increasing HDL cholesterol levels. This makes it a valuable tool in managing cardiovascular health.

Side Effects and Tolerability

While both niacin and nicotinic acid are generally well-tolerated, they can cause side effects, especially at higher doses. Niacin is known for its characteristic "niacin flush," a temporary redness and warmth of the skin caused by blood vessel dilation. This side effect can be minimized by using extended-release formulations. Nicotinic acid, on the other hand, is more likely to cause gastrointestinal disturbances, such as nausea, vomiting, and diarrhea. These side effects can often be managed by taking the medication with food or using extended-release formulations.

Dietary Sources

Niacin and nicotinic acid can be obtained through dietary sources, although their concentrations may vary. Foods rich in niacin include meat, fish, poultry, legumes, and whole grains. Nicotinic acid is also present in similar food sources, but at lower levels. Additionally, both compounds can be obtained through supplementation, either as individual supplements or as part of a multivitamin complex.


In conclusion, niacin and nicotinic acid are two forms of vitamin B3 that share many similarities but also exhibit some distinct attributes. While they have overlapping therapeutic uses and dietary sources, their differences in metabolism, bioavailability, and side effects make them suitable for specific applications. Understanding these nuances can help individuals and healthcare professionals make informed decisions regarding their use and supplementation. Whether it's maintaining healthy skin or managing cardiovascular health, niacin and nicotinic acid play vital roles in supporting overall well-being.

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