Niacin, also known as nicotinamide, is an essential form of vitamin B3 that helps prevent kidney, brain, and skin disorders. Aside from converting food into energy, it is also helps in a broad range of bodily functions such as maintenance of a healthy nervous system, proper blood circulation, hydrochloric acid production, secretion of bile and other digestive fluids, and sex hormone production.
Overall Health Benefits
- Lowers the risk of cardiovascular disease [1-4]
- Improves lipid profile [5-6]
- Treats migraines and headaches [7-8]
- Improves kidney function [9-11]
- Boosts brain power 
- Prevents cancer [13-15]
- Prevents and treats pellagra [16-17]
Proven Health Benefits
Lowers the Risk of Cardiovascular Disease
Studies suggest that this essential form of vitamin B3 can help protect against cardiovascular disease:
- In adults, niacin supplementation improved cardiovascular health. 
- A study showed that niacin supplementation can help prevent blood vessel rupture. 
- In adults, the combination of riboflavin and niacin reduced the risk of cardiovascular disease. 
- A study suggested that niacin supplementation can be an option for cardiovascular disease prevention. 
Improves Lipid Profile
Niacin has also been found to lower fatty acids or lipids in the blood:
- Administration of niacin in patients who are at higher risk for coronary artery disease resulted in lower lipid levels. 
- In diabetic patients, niacin administration improved lipid profile without affecting their sugar levels. 
Treats Migraines and Headaches
Studies suggest that niacin has pain-relieving properties that can be beneficial in patients with migraines and headaches:
- A study showed that niacin administration completely eliminated migraines and headaches in patients suffering from these conditions. 
- In a 62-year-old female patient, niacin significantly reduced the incidence of migraine. 
Improves Kidney Function
The beneficial effects of niacin on kidney function are backed by a number of studies:
- In Japanese patients, niacin treated kidney disease without any adverse side effects. 
- In patients with chronic renal failure, niacin prevented elevations in lipids and phosphate. 
- In rats with kidney failure, niacin inhibited inflammation, thus slowing down the progression of kidney disease. 
Boosts Brain Power
In one study, higher niacin concentration was found to reduce the risk of cognitive impairment.  This suggests that niacin supplementation can improve cognitive health and protect against various brain disorders.
Evidence also found that niacin can combat different types of cancer:
- In a rat model of cancer, niacin killed tumor cells and decreased the severity of side effects from chemotherapy. 
- In mice, supplementation with niacin prevented cancer by protecting against DNA damage. 
- In human breast cancer cells, niacin in combination with chemotherapy induced programmed cell death. 
Prevents and Treats Pellagra
Studies also found that niacin can be an effective treatment for pellagra, a condition characterized by skin inflammation and mouth sores:
- In patients with pellagra due to vitamin B3 deficiency, administration of niacin treated the condition. 
- A study found that niacin supplementation can help reduce the risk of pellagra. 
- Martens, C.R., Denman, B.A., Mazzo, M.R. et al. Chronic nicotinamide riboside supplementation is well-tolerated and elevates NAD+ in healthy middle-aged and older adults. Nat Commun 9, 1286 (2018). https://doi.org/10.1038/s41467-018-03421-7.
- Tetsuo Horimatsu, Andra L Blomkalns, Mourad Ogbi, Mary Moses, David Kim, Sagar Patel, Nicole Gilreath, Lauren Reid, Tyler W Benson, Jonathan Pye, Samah Ahmadieh, Allie Thompson, Nathan Robbins, Adrien Mann, Ashlee Edgell, Stephanie Benjamin, Brian K Stansfield, Yuqing Huo, David J Fulton, Gautam Agarwal, Nagendra Singh, Stefan Offermanns, Neal L Weintraub, Ha Won Kim, Niacin protects against abdominal aortic aneurysm formation via GPR109A independent mechanisms: role of NAD+/nicotinamide, Cardiovascular Research, Volume 116, Issue 14, 1 December 2020, Pages 2226–2238, https://doi.org/10.1093/cvr/cvz303.
- Available at http://www.kjcls.org/journal/view.html?doi=10.15324/kjcls.2019.51.4.484.
- Available at https://www.amjmed.com/article/S0002-9343(17)30158-4/fulltext.
- Bays, Harold. “Safety of Niacin and Simvastatin Combination Therapy.” The American Journal of Cardiology, vol. 101, no. 8A, 2008, 3B-8B.
- Xiang, Dan MM∗; Zhang, Qian MM; Wang, Yang-Tian MM Effectiveness of niacin supplementation for patients with type 2 diabetes, Medicine: July 17, 2020 – Volume 99 – Issue 29 – p e21235 doi: 10.1097/MD.0000000000021235.
- Prousky J, Seely D. The treatment of migraines and tension-type headaches with intravenous and oral niacin (nicotinic acid): systematic review of the literature. Nutr J. 2005;4:3. Published 2005 Jan 26. doi:10.1186/1475-2891-4-3.
- Available at https://www.mayoclinicproceedings.org/article/S0025-6196(11)62470-1/fulltext.
- Taketani Y, Masuda M, Yamanaka-Okumura H, Tatsumi S, Segawa H, Miyamoto K, Takeda E, Yamamoto H. Niacin and Chronic Kidney Disease. J Nutr Sci Vitaminol (Tokyo). 2015;61 Suppl:S173-5. doi: 10.3177/jnsv.61.S173. PMID: 26598845.
- Available at https://www.tandfonline.com/doi/full/10.3109/08860221003753323.
- Available at https://journals.physiology.org/doi/full/10.1152/ajprenal.00126.2009.
- Mousa TY, Mousa OY. Nicotinic Acid Deficiency. [Updated 2020 Aug 10]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557749/.
- Available at https://mct.aacrjournals.org/content/8/4/725.
- Ann C. Boyonoski, Jennifer C. Spronck, Robert M. Jacobs, Girish M. Shah, Guy G. Poirier, James B. Kirkland, Pharmacological Intakes of Niacin Increase Bone Marrow Poly(ADP-Ribose) and the Latency of Ethylnitrosourea-Induced Carcinogenesis in Rats, The Journal of Nutrition, Volume 132, Issue 1, January 2002, Pages 115–120, https://doi.org/10.1093/jn/132.1.115.
- Available at https://www.spandidos-publications.com/10.3892/or.2014.3661.
- Peechakara BV, Gupta M. Vitamin B3. [Updated 2020 Jun 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526107/.
- Matapandeu G, Dunn SH, Pagels P. An Outbreak of Pellagra in the Kasese Catchment Area, Dowa, Malawi. The American Journal of Tropical Medicine and Hygiene. 2017 May;96(5):1244-1247. DOI: 10.4269/ajtmh.16-0423.