Having enough niacin or vitamin B3 plays important roles in general good health. Also higher amount of niacin have crucial improvement of cardiovascular or heart health but also carry health risk. Niacin is also available supplement or over the counter. Although it has critical roles in cardiovascular health without knowing details taking higher amount can damage your health.
Niacin for crucial improvement of cardiovascular health and risk
Let’s first identify what important roles does niacin has?
Niacin contributes as major component of NAD and NADP, two coenzymes involved in cellular metabolism. (1) NAD participates in many oxidation reduction reactions in cells as reducing agent. That means NAD participates in reducing oxidative stress. On the other hand NADP serves as an electron carrier by being alternately oxidized and reduced.
Niacin favorably affects lipoproteins like very-low-density lipoprotein or VLDL, LDL, lipoprotein A and increases HDL. (2)
Lipoprotein A or Lp(a)
Lipoprotein A consists of a particle similar to LDL and 2 protein molecules known as ApoB and Apo(a). The Apo(a) particle is a very sticky protein particle, thought to be involved in the clotting system. High levels of Lp(a) have now been identified as an independent risk factor in cardiovascular disease, with a causal link to atherosclerosis (furring up of arteries), heart attacks, strokes, aortic valve disease and heart failure.(3) More specifically low molecular weight apo(a) is an independent predictor for coronary artery disease in people with kidney disease.(4)
Niacin and Lipoprotein A
Niacin reduces Lp(a) levels by up to 30% to 40% in a dose‐dependent manner. And in addition it exerts other potential beneficial effects by reducing LDL‐C, total cholesterol, triglycerides, and by raising high‐density lipoprotein cholesterol. (5)
A 24-week, prospective, open-label clinical trial recruited 30 men with previously received no lipid lowering therapy. They started niacin 500 mg with step wise dose increasing up to 1.5–2.0 g. The results they had found as Lp(a) decreased by 28%, Lp-PLA2 by 22% , C-reactive protein by 24% in major low apo(a) group. They concluded high dose niacin declines elevated Lp(a) level with low- but not high-molecular weight apo(a) phenotype. (6) The low apo(a) is the sticky particle and is an independent predictor for coronary artery disease.
Researcher indicates all other known mainly lower low density lipoprotein-cholesterol (LDL-c) but no or limited effect on levels of Lp(a). Only niacin has significant Lp(a) reducing effect. But it often is poorly tolerated.(7)
Effects of niacin on LDL, HDL, Triglycerides, VLDL(8)
On an average niacin
- Reduces LDL or bd cholesterol levels by 10%-25%
- Reduces triglycerides by 20%-50%
- Increases HDL level by 15%-35%
- Apart from that niacin also reduces very low-density lipoprotein (VLDL) particles
Also read best foods to reduce cholesterol naturally.
Some other beneficial results of niacin
Niacin dependent co enzyme NAD and NADP play important roles in multiple biological processes in brains such as neurotransmission and learning as well as memory. (9) Researchers found association of niacin deficiency with mental disorder.(10, 11)
Improve skin health
Both oral and skin application of niacin helps in protection of sun damage of skin. (12) In vitro and vivo; niacin enhances DNA repair, reduces UV radiation-induced suppression of skin immune responses, modulates inflammation and skin barrier function as well as restores cellular energy levels after UV exposure. (13) Researches also suggest protective effect of niacin in development of skin cancers.(14,15)
In prevention of pallegra
Pallegra with symptoms like inflamed skin, diarrhea, dementia, and sores in the mouth is also associated with niacin deficiency.(16)
Health risks of excessive niacin intake
Higher intake or therapeutic dose of niacin can cause some serious adverse effects.(17)
Niacin or Nicotinic acid supplementation may cause flushing; the skin on the patient’s face, arms, and chest turns a reddish color because of vasodilation of small subcutaneous blood vessels. You may also experience a burning, tingling, and itching sensations. These signs are typically transient and can occur within 30 minutes of intake or over days or weeks with repeated dosing. These symptoms are considered as unpleasant, rather than a toxic, side effect. However some form of niacin comes as flush free or no flush or lesser effect.
Higher dose of niacin can cause numbers of health problems including
Higher dose of niacin can cause gastrointestinal problem, such as nausea, heartburn, and abdominal pain
High dose of nicotinic acid or niacin for long time can cause liver damage.
Large dose also associated with impaired glucose tolerance and insulin resistance.
Similarly large dose is associated with blurred or impaired vision and macular edema.
Individual with arthritis gout should use niacin with caution. Niacin can cause an excess of uric acid in the blood or hyperuricemia.(18)
A wide variety of food contains niacin. Usually animal source of foods like meat, breast meat, fish like salmon, tuna contains higher percentage. Vegetarian sources include some grain, peanut, potato, some seeds, lentils, cereals fortified with niacin, banana, tomato, broccoli and more.
Above health risk were reported only with higher dose of niacin that comes with either supplement or drug. On the other hand niacin has some crucial improvement in cardiovascular health. No adverse effects have been reported from the consumption of naturally occurring niacin in foods. (17) Supplement of niacin usually comes with higher dose than RDA. Therefore you should only for supplementation under supervision of healthcare provider. That depends on whether good part over weigh the toxic effects.
Disclaimer: Information provided here are generalized information for educational purpose only, not intended to provide one to one health consultation or replace practice of a qualified practitioner. Different people may have different health condition and may have different reaction to the same food. Hence it has been advised to consult with health care provider before application of any of above guidelines. 1. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline, Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes and its Panel on Folate, Other B Vitamins, and Choline. Washington (DC): National Academies Press (US); 1998. 2. Kamanna VS, Kashyap ML., Mechanism of action of niacin, Am J Cardiol. 2008 Apr 17;101(8A):20B-26B. 3.https://www.heartuk.org.uk/genetic-conditions/high-lipoproteina 4.Kronenberg F, Neyer U, Lhotta K, Trenkwalder E, Auinger M, Pribasnig A, Meisl T, König P, Dieplinger H., The low molecular weight apo(a) phenotype is an independent predictor for coronary artery disease in hemodialysis patients: a prospective follow-up, J Am Soc Nephrol. 1999 May;10(5):1027- 36 5. Maciej Banach, Lipoprotein (a)—We Know So Much Yet Still Have Much to Learn …, Journal of the American Heart Association. ;5, 23 Apr 2016 6. Artemeva NV, Safarova MS, Ezhov MV, Afanasieva OI, Dmitrieva OA, Pokrovsky SN, Lowering of lipoprotein(a) level under niacin treatment is dependent on apolipoprotein(a) phenotype., Atheroscler Suppl. 2015 May;18:53-8 7.Vogt A,Hyperlipoproteinaemia(a) - apheresis and emerging therapies, Clin Res Cardiol Suppl. 2017 Mar;12(Suppl 1):12-17 8. https://www.health.harvard.edu/newsletter_article/on-call-niacin-for-cholesterol 9. Ying W., NAD+ and NADH in brain functions, brain diseases and brain aging, Front Biosci. 2007 Jan 1;12:1863-88 10.Wang W, Liang B., Case report of mental disorder induced by niacin deficiency, Shanghai Arch Psychiatry. 2012 Dec;24(6):352-4. 11. Rosemary A Fricker, Emma L Green, Stuart I Jenkins, and Síle M Griffin, The Influence of Nicotinamide on Health and Disease in the Central Nervous System, Int J Tryptophan Res. 2018; 11: 1178646918776658 12. Damian DL., Photoprotective effects of nicotinamide, Photochem Photobiol Sci. 2010 Apr;9(4):578-85 13. Damian DL., Nicotinamide for skin cancer chemoprevention, Australas J Dermatol. 2017 Aug;58(3):174-180 14. Chen AC et al, A Phase 3 Randomized Trial of Nicotinamide for Skin- Cancer Chemoprevention, N Engl J Med. 2015 Oct 22;373(17):1618-26 15. Nestor L, Clowry J, Molloy K, Connolly M, Salim A, Tobin AM., Nicotinamide for prevention of nonmelanoma skin cancers: a change in practice?, Clin Exp Dermatol. 2017 Dec;42(8):945-946 16.https://en.wikipedia.org/wiki/Pellagra 17.https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/ 18.Scott JT., Drug-induced gout, Baillieres Clin Rheumatol. 1991 Apr;5(1):39-60