Niacin (Niacinamide)

Overview

Niacinamide, also known as nicotinamide, is a form of vitamin B3, an essential water-soluble vitamin found naturally in foods such as meat, fish, milk, eggs, and green vegetables¹. It is used both as a dietary supplement and medication primarily to prevent and treat pellagra, a disease caused by niacin deficiency characterized by diarrhea, dermatitis, dementia, and if untreated, death³. Unlike niacin (nicotinic acid), niacinamide does not cause skin flushing, making it a preferred form for supplementation¹⁴. Historically, vitamin B3 was called vitamin PP (pellagra-preventive) due to its role in preventing this deficiency. Niacinamide also has topical uses, such as treating acne and improving aging skin by reducing hyperpigmentation and redness¹. It is recognized as an essential medicine by the World Health Organization and is widely available over the counter¹.

Forms and Variations

Niacinamide is available in several forms and formulations:

• Oral supplements: Tablets and capsules for systemic use to prevent or treat deficiency.
• Topical creams and serums: Used in dermatology for acne treatment and skin aging.
• Fortified foods: Many cereals and grain products are enriched with niacinamide to prevent deficiency in populations.

Niacinamide is chemically an amide of nicotinic acid (niacin), differing mainly in that it does not cause flushing. This makes it preferable for individuals sensitive to niacin’s side effects. Commercially, it is produced from nicotinic acid or nicotinonitrile¹. The choice of form depends on the intended use—oral for systemic deficiency, topical for skin conditions.

Dosage and Administration

The recommended dietary allowance (RDA) for vitamin B3 varies by age, sex, and physiological status, but typical adult doses of niacinamide for deficiency prevention range from 14 to 16 mg per day³. For therapeutic use, such as treating pellagra, higher doses may be prescribed under medical supervision.

Niacinamide is usually taken orally once or twice daily with meals to improve absorption and reduce gastrointestinal discomfort. Topical formulations are applied as directed, often once or twice daily, depending on the product and skin condition.

Because niacinamide is water-soluble, excess amounts are excreted in urine, but high doses should be monitored to avoid liver toxicity¹. It is important to follow dosing instructions and consult healthcare providers for long-term or high-dose use.

Scientific Research and Mechanism of Action

Niacinamide functions as a precursor to the coenzymes nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP), which are essential for cellular energy metabolism and DNA repair³. These coenzymes participate in oxidation-reduction reactions critical for converting carbohydrates, fats, and proteins into usable energy.

Research has demonstrated niacinamide’s role in maintaining healthy skin barrier function, reducing inflammation, and modulating immune responses, which underlies its use in dermatology for acne and skin aging¹⁵. Clinical studies have shown that topical niacinamide can improve skin texture, reduce hyperpigmentation, and decrease redness.

Current research continues to explore niacinamide’s potential in managing conditions such as diabetes, osteoarthritis, and cancer, though evidence remains limited and inconclusive for many of these uses⁵. Overall, niacinamide’s biochemical role in energy metabolism and cell health is well established.

Benefits and Potential Uses

Niacinamide’s proven benefits include:

• Prevention and treatment of pellagra: Corrects vitamin B3 deficiency and associated symptoms¹⁴.
• Skin health: Topical niacinamide improves acne, reduces inflammation, hyperpigmentation, and signs of aging¹⁵.
• Cellular energy metabolism: Supports enzymatic reactions essential for converting nutrients into energy³.

Potential uses under investigation include management of diabetes, osteoarthritis, and cancer, but these require further clinical validation⁵. Niacinamide does not lower cholesterol, unlike niacin, and thus is not used for lipid management.

Side Effects and Risks

Niacinamide is generally well tolerated with minimal side effects at normal doses. Common mild side effects may include gastrointestinal discomfort such as nausea or upset stomach¹. Unlike niacin, it does not cause flushing or itching.

At high doses, there is a risk of liver toxicity, so caution is advised when using large therapeutic doses¹. Pregnant women can safely use normal amounts of niacinamide.

Individuals with liver disease or those taking hepatotoxic medications should use niacinamide cautiously and under medical supervision.

Interactions and Precautions

Niacinamide has few known drug interactions but should be used cautiously with medications metabolized by the liver due to potential additive hepatotoxicity¹. It does not interact with cholesterol-lowering drugs as niacin does.

Precautions include monitoring liver function during high-dose therapy. Pregnant and breastfeeding women can generally use niacinamide safely at recommended doses.

There are no specific medical procedure considerations, but disclosure of supplement use to healthcare providers is recommended.

Impact on Biomarkers

Niacinamide supplementation can influence biomarkers related to vitamin B3 status, such as plasma niacin and NAD levels. It does not significantly affect lipid profiles, unlike niacin⁵. Liver enzymes should be monitored during high-dose use to detect potential hepatotoxicity.

Overdose and Toxicity

Excessive intake of niacinamide can lead to liver toxicity, with symptoms including jaundice, fatigue, nausea, and abdominal pain¹. The safe upper limit for adults is generally considered to be around 35 mg/day from supplements, though therapeutic doses may be higher under medical supervision.

Because niacinamide is water-soluble, mild overdoses are usually excreted, but chronic high doses increase risk of adverse effects. Prompt medical attention is advised if overdose is suspected.

Disclaimer

The information provided in this document is for educational purposes only and does not constitute medical advice. It is essential to consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.