Vitamin B3: benefits, dosage, contraindications
Other name(s)
Niacin, Niacinamide, Vitamin PP, nicotinamide
Scientific name(s)
3-Pyridinecarboxylic Acid
Family or group:
Vitamins
Indications
Scoring methodology
EFSA approval.
Vitamin B3 deficiency ✪✪✪✪✪
A niacin intake insufficiency is sometimes observed in people who suffer from inflammatory bowel diseases such as Crohn's disease or celiac disease, from liver cirrhosis, or from alcoholism. Severe deficiencies are the cause of pellagra syndrome. Pellagra is an essentially cutaneous condition with a painful erythema extending to parts exposed to light (pellagrous erythema), sometimes accompanied by stomatitis and glossitis, and often by intense physical and mental asthenia with delirious melancholy tending toward depression (pellagrous dementia). Digestive disorders (gastritis, enterocolitis) with diarrhea, and later sensory and painful neurological disorders, have also been observed in cases of severe niacin deficiency. In confirmed cases of 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 ✪✪✪✪✪
The European health authorities (EFSA, European Food Safety Authority, and the European Commission) have determined that foods and food 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 with 18% to 55% for statins. It can also decrease triglycerides by 20% to 50%, increase HDL cholesterol by 13% to 35%, decrease apolipoprotein B levels by 2% to 20%, and decrease lipoprotein levels by 23%. Therefore, niacin may be considered for patients with mixed hyperlipidemia or patients who need to raise high-density lipoprotein (HDL) cholesterol and lower triglycerides. In addition, niacin can be combined with other cholesterol-lowering drugs (statins) when diet and monotherapy are not sufficiently effective. The effects of niacin are dose-dependent. The greatest effects on HDL cholesterol and triglycerides occur at a dose of 1 to 1.5 grams per day. The greatest effects of niacin on LDL cholesterol are observed with a dose of 2 to 3 grams per day.
Posologie
Oral
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 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
Adults
gel
Metabolic syndrome ✪✪✪✪✪
Clinical research shows that taking niacin at a dose of 2 grams per day orally for 16 weeks reduces triglyceride levels by 39 mg/dL and increases high-density lipoprotein (HDL) cholesterol by 5.4 mg/dL compared with baseline in patients with metabolic syndrome. These improvements are significant compared with placebo and are even greater when niacin is taken with omega-3 ethyl esters at a dose of 4 grams per day orally. However, niacin does not appear to improve postprandial glucose levels in patients with metabolic syndrome.
Posologie
Oral
2 g
Adults
Atherosclerosis ✪✪✪✪✪
In vitro studies suggest that niacin may prevent the formation of atherosclerotic plaques by reducing inflammation and endothelial injury through several mechanisms.nnIn humans, doses of 2 g of niacin may have some effect on the progression of atherosclerosis in patients with atherosclerosis, when used in combination with statins. The efficacy of niacin at lower doses is less clear.nn
Posologie
Oral
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 randomized controlled trial: the NIA plaque study.
Migraine ✪✪✪✪✪
A study assessed the relationship between niacin intake and the prevalence of migraine among U.S. adults using data from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2004. It found a relationship between niacin intake and migraine, with an inflection point around 21.0 mg/day: as niacin consumption increases up to a certain point (21 mg per day), fewer people suffer from migraines. Beyond this threshold, consuming more niacin does not provide additional benefits for reducing migraines. This may be due to niacin's roles in regulating serotonin levels and supporting mitochondrial function, thereby improving brain energy and reducing oxidative stress.
Posologie
Oral
1 - 21 mg
Properties
Essential
Niacin is necessary to ensure the functioning of a large number of NAD- or NADP-dependent enzymes, in other words most dehydrogenases, oxidoreductases and other reductases. Thus, niacin is used in the synthesis of enzymes that are involved, among other things, in the production of energy from nutrients, in the synthesis of fatty acids and sex hormones, in the formation of red blood cells and in the regulation of gene activity. Severe vitamin B3 deficiencies are the cause of pellagra. Pellagra is a condition that is primarily cutaneous, 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 weakness with delusional melancholia tending toward depression (pellagrous dementia), and finally by digestive involvement (gastritis, enterocolitis) with diarrhea and, later, 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 from 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 the rate of chylomicron triglyceride clearance from plasma, secondary to an increase in lipoprotein lipase activity. Furthermore, 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 the smallest, most dense LDL particles, and increase the number of the largest LDL particles. In addition, in vitro studies suggest that niacin reduces triglyceride synthesis by inhibiting the activity of diacylglycerol acyltransferase 2 (DGAT2): a hepatic enzyme that plays a key role in esterifying fatty acids to form triglycerides.
Usages associés
Neurological
Vitamin B3, encompassing niacin (nicotinic acid) and niacinamide (nicotinamide), plays a crucial role in the nervous system and in essential biological reactions. It is being particularly studied for its potential in the treatment of Parkinson's disease, a condition in which plasma niacin levels are often reduced, both because of the disease itself and because of 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. On a biochemical level, niacin is a precursor of nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), coenzymes essential for oxidation-reduction reactions, ATP synthesis, and ADP-ribose transfer reactions. These processes are vital for cellular energy production, which explains the anti-fatigue effect of vitamin B3.
Usages associés
Cardiovascular
Niacin appears to have cardioprotective effects. Indeed, in patients with hyperlipidemia or peripheral arterial disease, niacin appears to reduce plasma fibrinogen concentrations and may stimulate fibrinolysis. Moreover, in vitro, niacin inhibits the formation of certain cellular mediators in platelets and increases the production of others, thereby resulting in inhibition of platelet aggregation. Furthermore, a meta-analysis revealed a reduced risk of developing coronary artery disease, a possible decreased risk of myocardial infarction, and reduced rates of stroke in dyslipidemic subjects using pharmacological doses of niacin compared with controls. However, no significant change in overall cardiovascular mortality was observed with the use of niacin at pharmacological doses.
Usages associés
Dermatologic effect
Low levels of glycosaminoglycans (GAGs) (these are carbohydrate macromolecules) are necessary for the normal structure of healthy skin. Increased levels of GAGs are associated with damaged or wrinkled skin. It has been noted that niacinamide reduces the production of GAGs in aged fibroblasts. The main metabolite of niacin, methyl nicotinamide (MNA), can bind directly to GAGs, unlike nicotinamide itself. On the other hand, MNA has anti-inflammatory effects when applied topically, which makes it useful in the treatment of acne vulgaris (a chronic skin disorder generally characterized by follicular hyperkeratinization, overproduction of sebum, and chronic inflammation of the pilosebaceous unit). Finally, niacin appears to have a skin-lightening effect, secondary to the reduction of melanosome transfer (these are intracellular organelles in which melanins are produced; in humans, keratinocytes distribute the melanosomes above their nucleus, thereby protecting it from ultraviolet radiation).
Usages associés
Safe dosage
Child aged 1 to 3 years: 1.6 mg
The values refer 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 related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group in question.
Child aged 1 to 3 years: 2 mg (nicotinic acid)
Child aged 4 to 6 years: 1.6 mg
The values refer to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. nnNE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are related to energy requirements and are therefore expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy requirements of the group concerned.nn
Child aged 4 to 6 years: 3 mg (nicotinic acid)
Child aged 7 to 10 years: 1.6 mg
The values refer to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. nnNE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are related to energy requirements and are therefore expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy requirements of the group concerned.nn
Child aged 7 to 10 years: 4 mg (nicotinic acid)
Infant aged 7 to 11 months: 1.6 mg
The values refer to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. nnNE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are related to energy requirements and are therefore expressed in mg NE / MJ. Values expressed in mg NE / day can be calculated based on the energy requirements of the group concerned.nn
Child aged 11 to 14 years: 1.6 mg
The values refer 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 related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group concerned.
Child aged 11 to 14 years: 6 mg
Child aged 15 to 17 years: 1.6 mg
The values refer 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 related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group concerned.
Child aged 15 to 17 years: 8 mg (nicotinic acid)
Adult 18 years and older: 1.6 mg
The values refer 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 related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group concerned.
Adult 18 years and older: 10 mg (nicotinic acid)
Pregnant women 18 years and older: 1.6 mg
The values refer to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. nnNE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group concerned.nn
Lactating women aged 18 years and older: 1.6 mg
The values refer to niacin in the form of nicotinamide and nicotinic acid. Niacin can be synthesized in the human body from tryptophan, an essential amino acid. nnNE: niacin equivalent (1 NE = 1 mg niacin = 60 mg dietary tryptophan). Niacin requirements are related to energy requirements and are therefore expressed in mg NE/MJ. Values expressed in mg NE/day can be calculated based on the energy requirements of the group concerned.nn
Interactions
Médicaments
Antiplatelet agents/Anticoagulants: moderate interaction
Several cases of impaired synthesis of coagulation factors and coagulopathy have been reported in patients taking extended-release niacin. In addition, thrombocytopenia has been reported in patients treated with niacin or with niacin and lovastatin. Theoretically, concomitant use of niacin and anticoagulants or antiplatelet agents could increase the risk of bleeding in some patients.
Antidiabetic agents: moderate interaction
Niacin alters glucose tolerance in a dose-dependent manner, likely by causing or worsening insulin resistance and by increasing hepatic glucose production. In some patients, glucose levels rise at the start of niacin therapy, then return 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 initiated.
Uricosurics: moderate interaction
High doses of niacin can reduce urinary excretion of uric acid, potentially leading to hyperuricemia. Dosage adjustment of uricosurics may be necessary in patients who begin taking niacin
Bile acid sequestrants: moderate interaction
Some evidence suggests that the concomitant use of niacin and bile acid sequestrants may increase the risk of myopathy. In addition, bile acid sequestrants can bind niacin and decrease its absorption.
Thyroid hormone medications: moderate interaction
Clinical evidence suggests that taking niacin can reduce serum globulin levels and moderately lower thyroxine (T4) levels. Theoretically, niacin could reduce the effects of certain thyroid hormones.
Contraindications
Gastric ulcer: contraindicated
Large amounts of niacin could exacerbate gastroduodenal ulcer disease.nn
Hypotension: contraindicated
Niacin can cause hypotension.nn
