Niacin (Vitamin B3)

    Researchedby:
    Last Updated: October 6, 2024

    Niacin is an essential B-vitamin. Supplementation results in improved cholesterol and triglyceride levels. However, since a side-effect of supplementation is increased insulin resistance, niacin supplementation only provides benefits for cardiovascular health if precautions are taken.

    Summary

    Vitamin B3 refers to the molecule commonly called nicotinic acid, or niacin, though it may also refer to the other vitamin B3 vitamer, called nicotinamide. Vitamin B3 is necessary to support the function of many enzymes.

    Niacin supplementation is very effective at normalizing blood lipid levels. Supplementation increases HDL-C levels and decreases LDL-C and triglyceride levels. This makes niacin look like a great cardioprotective supplement on paper. Unfortunately, niacin supplementation does not reliably result in a reduced risk of cardiovascular disease, possibly because it also increases insulin resistance, which could negate the benefits niacin provides for blood lipid levels.

    Niacin supplementation is theorized to benefit cognition and longevity. This is because niacin supplementation increases cellular nicotinamide adenine dinucleotide (NAD+) levels. Preliminary evidence suggests increased NAD+ levels may result in the above benefits, but much more research is needed to determine if this effect actually occurs.

    Topical application of nicotinamide is sometimes used for skin health, though it is not as effective as vitamin A. Nicotinamide is used for topical application because it does not result in the flushed skin that niacin supplementation can cause.

    Current evidence suggests prolonged niacin supplementation increases insulin resistance because it hinders the ability of insulin to suppress glucose synthesis in the liver. This causes an increase in blood glucose levels, which leads to lowered insulin sensitivity over time, since the relevant receptor is eventually desensitized to the elevated glucose levels in the blood.

    The flush caused by niacin supplementation is a temporary effect. Though it may be uncomfortable, it is not harmful. There are many case studies describing people overdosing on niacin in an effort to pass a urine test. Niacin overdose results in multiple organ failure and is not effective at masking a urine test.

    What are other names for Niacin (Vitamin B3)

    Note that Niacin (Vitamin B3) is also known as:
    • Niacin
    • Vitamin B3
    • Nicotinamide Riboside
    Niacin (Vitamin B3) should not be confused with:

    Dosage information

    Most of the benefits from niacin supplementation occur after doses of at least one gram. This is approximately 5,000% the recommended daily intake.

    Research Breakdown

    References

    1. ^Depeint F, Bruce WR, Shangari N, Mehta R, O'Brien PJMitochondrial function and toxicity: role of the B vitamin family on mitochondrial energy metabolismChem Biol Interact.(2006 Oct 27)
    2. ^Selhub JFolate, vitamin B12 and vitamin B6 and one carbon metabolismJ Nutr Health Aging.(2002)
    3. ^Chen AC, Martin AJ, Choy B, Fernández-Peñas P, Dalziell RA, McKenzie CA, Scolyer RA, Dhillon HM, Vardy JL, Kricker A, St George G, Chinniah N, Halliday GM, Damian DLA Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer ChemopreventionN Engl J Med.(2015 Oct 22)
    4. ^Brasky TM, White E, Chen CLLong-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) CohortJ Clin Oncol.(2017 Oct 20)
    5. ^White E, Patterson RE, Kristal AR, Thornquist M, King I, Shattuck AL, Evans I, Satia-Abouta J, Littman AJ, Potter JDVITamins And Lifestyle cohort study: study design and characteristics of supplement usersAm J Epidemiol.(2004 Jan 1)
    6. ^Kim YIFolate and colorectal cancer: an evidence-based critical reviewMol Nutr Food Res.(2007 Mar)
    7. ^Kok DE, Dhonukshe-Rutten RA, Lute C, Heil SG, Uitterlinden AG, van der Velde N, van Meurs JB, van Schoor NM, Hooiveld GJ, de Groot LC, Kampman E, Steegenga WTThe effects of long-term daily folic acid and vitamin B12 supplementation on genome-wide DNA methylation in elderly subjectsClin Epigenetics.(2015 Nov 14)
    8. ^Corbin JM, Ruiz-Echevarría MJOne-Carbon Metabolism in Prostate Cancer: The Role of Androgen SignalingInt J Mol Sci.(2016 Jul 27)