Vitamin B3: Benefits, Dosage, Contraindications
Other name(s)
Niacin, Niacinamide, Vitamin PP, Nicotinamide
Scientific name(s)
3-Pyridinecarboxylic Acid
Family or group:
Vitamins
Indications
Rating methodology
EFSA approval.
Vitamin B3 Deficiency ✪✪✪✪✪
Niacin deficiency is sometimes observed in people suffering from inflammatory bowel diseases such as Crohn's disease or celiac disease, liver cirrhosis, or alcoholism. Severe deficiencies are the cause of pellagra syndrome. Pellagra is mainly a skin condition with a painful erythema extending to areas exposed to light (pellagrous erythema), sometimes accompanied by stomatitis and glossitis, and often by intense physical and mental asthenia with delusional melancholia leading to depression (pellagrous dementia). Digestive disorders (gastritis, enterocolitis) with diarrhea and eventually sensory and painful neurological disorders have also been observed in severe niacin deficiencies. In the case of proven intake insufficiency, a daily dose of 500 to 1000 mg has been used. In cases of pellagra in children, a dose between 100 and 300 mg per day has been used.
Posologie
Oral
100 - 1000 mg
Adults, Children
Fatigue ✪✪✪✪✪
European health authorities (EFSA, European Food Safety Authority, and the European Commission) have stated that foods and dietary supplements containing vitamin B3 (niacin) can claim to contribute to the reduction of fatigue.
Posologie
Oral
10 mg
Adults
Dyslipidemia ✪✪✪✪✪
Niacin can reduce LDL cholesterol by about 5% to 25%, compared to 18% to 55% for statins. It can also lower triglycerides by 20% to 50%, increase HDL by 13% to 35%, lower apolipoprotein B levels by 2% to 20%, and lower lipoprotein levels by 23%. Therefore, niacin may be considered for patients with mixed hyperlipidemia or patients who need to increase high-density lipoprotein (HDL) cholesterol and lower triglycerides. Additionally, niacin can be combined with other cholesterol-lowering medications (statins) when diet and monotherapy are not sufficiently effective. Niacin's effects are dose-dependent. The most significant effects on HDL cholesterol and triglycerides occur at a dose of 1 to 1.5 grams per day. The most significant effects of niacin on LDL cholesterol are observed at doses of 2 to 3 grams per day.
Posologie
Oral administration
1 - 3 g
Adults
Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group.
2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.
Safety and effectiveness of Niaspan when added sequentially to a statin for treatment of dyslipidemia.
Acne ✪✪✪✪✪
Studies have shown that the topical application of a 4% nicotinamide gel is as effective as 1% clindamycin gel in reducing the severity of acne after at least 8 weeks of treatment and tends to work better than clindamycin on oily skin.
Posologie
Topical administration
Adults
gel
Metabolic Syndrome ✪✪✪✪✪
Clinical research shows that taking 2 grams of niacin daily orally for 16 weeks reduces triglyceride levels by 39 mg/dL and increases high-density lipoprotein (HDL) cholesterol by 5.4 mg/dL compared to baseline levels in patients with metabolic syndrome. These improvements are significant compared to placebo treatment and are even more substantial when niacin is taken with 4 grams daily of omega-3 ethyl esters orally. However, niacin does not appear to improve postprandial glucose levels in patients with metabolic syndrome.
Posologie
Oral administration
2 g
Adults
Atherosclerosis ✪✪✪✪✪
In vitro studies suggest that niacin may prevent atherosclerosis plaque formation by reducing inflammation and endothelial damage through several mechanisms. In humans, doses of 2 g niacin may have some effect on the progression of atherosclerosis in patients with atherosclerosis when taken with statins. The effectiveness of lower doses of niacin is less clear.
Posologie
Oral administration
2 g
Adults
Effects of high-dose modified-release nicotinic acid on atherosclerosis and vascular function: a randomized, placebo-controlled, magnetic resonance imaging study.
Arterial Biology for the Investigation of the Treatment Effects of Reducing Cholesterol (ARBITER) 2: a double-blind, placebo-controlled study of extended-release niacin on atherosclerosis progression in secondary prevention patients treated with statins.
Meta-analysis of the effect of nicotinic acid alone or in combination on cardiovascular events and atherosclerosis.
MRI-measured regression of carotid atherosclerosis induced by statins with and without niacin in a randomised controlled trial: the NIA plaque study.
Migraine ✪✪✪✪✪
A study evaluated the relationship between niacin intake and migraine prevalence in American adults, using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. It revealed a link between niacin intake and migraines, with a turning point around 21.0 mg/day: the more niacin is consumed, up to a certain point (21 mg per day), the less people suffer from migraines. Beyond this threshold, consuming more niacin does not provide additional benefits for reducing migraines. This could be due to niacin's roles in regulating serotonin levels and supporting mitochondrial function, thereby contributing to improved brain energy and reduced oxidative stress.
Posologie
Oral administration
1 - 21 mg
Properties
Essential
Niacin is necessary to ensure the functioning of a large number of NAD or NADP enzymes, namely most dehydrogenases, oxidoreductases, and other reductases. Thus, niacin serves in the synthesis of enzymes involved, among others, in energy production from nutrients, fatty acid synthesis, sexual hormone synthesis, red blood cell formation, and gene activity regulation. Severe vitamin B3 deficiencies cause the pellagra syndrome. Pellagra is mainly a skin disease with a painful erythema extending to areas exposed to light (pellagrous erythema), sometimes accompanied by stomatitis and glossitis, and often by intense physical and mental asthenia with delusional melancholia leading to depression (pellagrous dementia), eventually digestive ailments (gastritis, enterocolitis) with diarrhea and latently sensory and painful neurological disorders.
Usages associés
Hypolipidemic
By binding to a G protein-coupled receptor on adipocytes, niacin inhibits the release of free fatty acids by adipose tissue and inhibits the accumulation of cyclic AMP that controls triglyceride lipase activity and thus lipolysis. It also decreases hepatic synthesis of LDL and VLDL, and increases chylomicron triglyceride clearance rate from plasma, secondary to an increase in lipoprotein lipase activity. Moreover, clinical research has shown that niacin can reduce the number of large VLDL particles, increase the number of large HDL particles, decrease the number of smallest and densest LDL particles, and increase the number of largest LDL particles. On the other hand, in vitro research suggests that niacin reduces triglyceride synthesis by inhibiting the activity of diacylglycerol acyltransferase 2 (DGAT2), a liver enzyme that plays a key role in fatty acid esterification to form triglycerides.
Usages associés
Neurological
Vitamin B3, encompassing niacin (nicotinic acid) and niacinamide (nicotinamide), plays a crucial role in the nervous system and essential biological reactions. It's particularly studied for its potential in treating Parkinson's disease, a condition where plasma niacin levels are often reduced, both due to the disease itself and its treatment with levodopa. Although preliminary clinical research indicates that daily supplementation with slow-release niacin (250 mg) for 12 months may increase plasma niacin levels in adults with Parkinson’s, no direct link has been established between niacin levels and improvements in motor scores. Biochemically, niacin is a precursor of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), essential coenzymes for redox reactions, ATP synthesis, and ADP-ribose transfer reactions. These processes are vital for cellular energy production, explaining the anti-fatigue effect of vitamin B3.
Usages associés
Cardiovascular
Niacin appears to have cardioprotective effects. Indeed, in patients with hyperlipidemia or peripheral artery disease, niacin seems to reduce plasma fibrinogen concentrations and potentially stimulate fibrinolysis. Additionally, in vitro, niacin inhibits the formation of certain cellular mediators in platelets and increases the production of others, thereby inhibiting platelet aggregation. Furthermore, a meta-analysis revealed a decreased risk of developing coronary heart disease, a possible reduction in the risk of myocardial infarction, and a decrease in stroke rates in dyslipidemic subjects using pharmacological doses of niacin compared to controls. However, no significant change in overall cardiovascular mortality was observed with pharmacological doses of niacin.
Usages associés
Dermatological Effect
Low levels of glycosaminoglycan (GAG) (these are carbohydrate macromolecules) are necessary for a normal structure of healthy skin. Increased levels of GAG are associated with damaged or wrinkled skin. It has been noted that niacinamide reduces GAG production in aged fibroblasts. The main metabolite of niacin, methylnicotinamide (MNA), can directly bind to GAG, unlike nicotinamide itself. Additionally, MNA has anti-inflammatory effects when applied topically, making it useful in treating acne vulgaris (a chronic skin disorder generally characterized by follicular hyperkeratinization, sebaceous overproduction, and chronic inflammation of the pilosebaceous unit). Finally, niacin seems to have a skin-lightening effect, secondary to reducing melanosome transfer (melanosomes are intracellular organelles within which melanin is produced; in humans, keratinocytes distribute melanosomes above their nucleus to protect it from ultraviolet radiation).
Usages associés
Safety dosage
Child from 1 to 3 years: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 1 to 3 years: 2 mg (nicotinic acid)
Child from 4 to 6 years: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 4 to 6 years: 3 mg (nicotinic acid)
Child from 7 to 10 years: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 7 to 10 years: 4 mg (nicotinic acid)
Infant from 7 to 11 months: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 11 to 14 years: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 11 to 14 years: 6 mg
Child from 15 to 17 years: 1.6 mg
Values relate to niacin as nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin needs are linked to energy needs and therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy needs of the considered group.
Child from 15 to 17 years: 8 mg (nicotinic acid)
Adult from 18 years: 1.6 mg
The values relate to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are linked to energy needs and thus expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy needs of the considered group.
Adult from 18 years: 10 mg (nicotinic acid)
Pregnant woman from 18 years: 1.6 mg
The values relate to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are linked to energy needs and thus expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy needs of the considered group.
Breastfeeding woman from 18 years: 1.6 mg
The values relate to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. NE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are linked to energy needs and thus expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy needs of the considered group.
Interactions
Médicaments
Antiplatelet/Anticoagulant: moderate interaction
Several cases of impaired synthesis of coagulation factor and coagulopathy have been reported in patients taking extended-release niacin. Moreover, thrombocytopenia has been reported in patients treated with niacin or niacin and lovastatin. Theoretically, the concurrent use of niacin and anticoagulants or antiplatelets could increase bleeding risk in some patients.
Antidiabetic: moderate interaction
Niacin impairs glucose tolerance in a dose-dependent manner, possibly by causing or worsening insulin resistance and increasing hepatic glucose production. In some patients, glucose levels increase at the start of niacin treatment, then revert to baseline once a stable dose is reached. Approximately 10% to 35% of diabetic patients may require therapeutic adjustments of hypoglycemic medications when niacin is introduced.
Uricosurics: moderate interaction
High doses of niacin can reduce urinary excretion of uric acid, potentially leading to hyperuricemia. A dosage adjustment of uricosurics may be necessary for patients starting niacin.
Bile acid sequestrants: moderate interaction
Some evidence suggests that concurrent use of niacin and bile acid sequestrants may increase the risk of myopathy. Additionally, bile acid sequestrants may bind niacin and decrease its absorption.
Thyroid hormone-based medicines: moderate interaction
Clinical evidence suggests that taking niacin may reduce serum globulin levels and moderately reduce thyroxine (T4) levels. Theoretically, niacin could reduce the effects of some thyroid hormones.
Contraindications
Gastric ulcer: prohibited
Large amounts of niacin might activate peptic ulcer disease.
Hypotension: prohibited
Niacin can cause hypotension.
