The B Vitamin Series, Vitamin B3
Vitamin B3, also known as niacin, was the third discovered vitamin within the B group. The discovery of vitamin B3 is closely linked with the story of Pellagra. Pellagra was extremely common throughout history, especially among malnourished, unprivileged groups whose diet consisted predominantly of corn products.
However, the disease spread to modernised societies, such as the United States, shortly after 1900 when new processing techniques removed some naturally-occurring micronutrients within foods such as grain. The symptoms of Pellagra were so severe that health experts strongly believed there was a widespread infection. It wasn’t until 1913 when Casimir Funk, a Polish-American biochemist, accidentally isolated vitamin B3 during his research for another disease known as BeriBeri (caused by a deficiency of vitamin B1). Although it was not relevant to Funk’s research at the time, Austrian-American physician Joseph Goldberger wanted to analyse the potential benefits of this nutrient and its relevance to other diseases. He went on to alter the diets of prisoners in a Mississippi institute to try and analyse what food groups would prevent the onset of Pellagra. Corn-fed prisoners were noted to be lacking a dietary factor that was not preventing Pellagra, as opposed to prisoners on a meat and dairy based diet. Goldberger cured the corn-fed prisoners by use of vitamin B3 supplementation, a nutrient that he also isolated from the meat and dairy. His research changed the processing methods of industrial grain manufacturers that still exist today, by recommending the enrichment of grain and maize products with this nutrient to try and prevent widespread B3 deficiencies.
What is the prevalence of vitamin B3 deficiency?
In developed countries, vitamin B3 deficiency is rare and is typically only found in alcoholics. However, analysis of the deficiency has not been fully studied, so no current statistics are available on its prevalence. Vitamin B3 deficiency is usually only diagnosed when there are clinical factors identical to Pellagra. A reliable and accurate biochemical assessment method for niacin nutritional status is not yet available, because vitamin B3 intake does not seem to appreciably alter serum and urine concentrations of nicotinic acid unless circumstances are severe. Pellagra diagnosis raises its own issues, as vitamin B3 deficiency can coexist with other B vitamin deficiencies, including vitamin B2 and B6, which present similar symptoms.
National Diet and Nutrition Surveys also tend to avoid analyse of B3 deficiency rates, as it is not a nutrient that has raised a significant cause for concern. More data is needed to assess the risk of primary or secondary vitamin B3 deficiency, irrespective of Pellagra diagnosis.
What are the symptoms of vitamin B3 deficiency?
The most common symptoms of deficiency are fatigue, indigestion, vomiting, poor circulation and depression. As previously mentioned, B3 deficiency may only be noticed when levels are severely low and Pellagra symptoms are apparent. Pellagra symptoms are scaly or cracked skin, diarrhoea and dermatitis. In fact, "pellagra" was originally named "pelle agra," which is the Italian expression for rough or raw skin. Pellagra has the potential to be fatal as it significantly affects the digestive and nervous system, but this only occurs if the disease is left untreated. Digestive issues are usually indicated by inflammation of the mouth, or if one notices constipation. Problems with the nervous system are noted by increased fatigue, extreme headaches or regular cases of memory loss. If you notice any of these symptoms it is important to report them to your General Practitioner.
What foods contain vitamin B3?
Vitamin B3 can be found in a wide range of food groups. Plant-based sources are mushrooms, sunflower seeds, peanuts, espresso, soybeans, potatoes, enoki, all bran, peas, lentils, pasta, grains and falafel. Animal-based sources are tuna, mackerel, salmon, chicken, turkey, pork, lamb and beef. The bioavailability of animal sources versus plant sources is similar, with both sources having an 80%+ bioavailability. Based on this, it is irrelevant whether vitamin B3 is consumed from a sole source or a variety of foods. Corn is the only exception to this, as it is connected to several peptides and other inhibitory factors which negatively affect niacin absorption.
How much do you need per day?
|0-6 months||2 mg||2 mg|
|7-12 months||4 mg||4 mg|
|1-3 years||6 mg||8 mg|
|4-8 years||6 mg||8 mg|
|9-13 years||12 mg||12 mg|
|14-18 years||16 mg||14 mg||18 mg||17 mg|
|19-30 years||16 mg||14 mg||18 mg||17 mg|
|31-50 years||16 mg||14 mg||18 mg||17 mg|
|51-70 years||16 mg||14 mg|
|>70 years||16 mg||14 mg|
What are the health benefits of vitamin B3?
Vitamin B3 is effective at lowering cholesterol, and has been used as prescription medication for this reason. A very large study showed a 10% improvement in cholesterol levels and a 26% reduced incidence of stroke over a 6 year period . These benefits are mainly due to B3’s protective effects on the cardiovascular system by decreasing the amount of serum lipoproteins. In addition, vitamin B3 can stop the breakdown of apolipoprotein A1, a protein that helps make HDL, and therefore has shown to raise HDL cholesterol levels by 15-35% . It may also prevent heart disease risk by reducing inflammation and oxidative damage .
In vitro studies, analysing the effect of vitamin B3 on cell activity, provide evidence that this micronutrient can stabilise genes . This is important for cancer prevention, which is formed from DNA damage when cell activity is sporadic. Vitamin B3 is needed to prevent improper ADP-ribosylations which decreases DNA damage at DNA strand breaks, and increases cell signalling and apoptosis. Rat models have shown a reduced rate of DNA repair when B3 levels are inadequate . In addition, case control studies in Italy and Sweden demonstrate the association with vitamin B3 and a significantly decreased (~40%) incidence of mouth, throat and esophageal cancers .
Diabetes risk is also decreased with vitamin B3 consumption. Niacin has shown in both animal studies and mechanistic studies to protect β-cells from toxic chemicals and oxidative damage . High doses of vitamin B3 is even used as a method to protect β-cells in those already diagnosed with insulin-dependent diabetes mellitus.
Vitamin B3 can also boost brain function, because niacin is necessary to form the coenzymes NAD and NADP, which maintain cognitive function and produce energy. Studies show a decrease in Alzheimer’s risk when B3 levels are normal, and might benefit cognitive abilities . Furthermore, focus and mental clarity has shown to improve with vitamin B3 intake, although research is limited .
Vitamin B3 is found in mainly in mushroom, beans, fish and different meats. It has benefits such as lowering cholesterol, improving brain function, and decreasing risk of diabetes and some types of cancer. A lack of vitamin B3 can result in fatigue, indigestion and depression. Severe deficiencies can cause Pellagra which negatively affects the nervous and digestive system, and can be fatal if untreated.
- Guyton. JR et al. (1998). Treatment of hyperlipidemia with combined niacin-statin regimens, Am J Cardiol.
- McKenney. J. (2004). New Perspectives on the Use of Niacin in the Treatment of Lipid Disorders, Arch Intern Med
- Kamanna. VS et al. (1998). Mechanism of action of niacin, Am J Cardiol.
- Negrini. S. (2010). Genomic instability--an evolving hallmark of cancer, Nat Rev Mol Cell Biol.
- Kostecki. LM et al. (2007). Niacin deficiency delays DNA excision repair and increases spontaneous and nitrosourea-induced chromosomal instability in rat bone marrow, Mutat Res.
- Negri. E et al. (2000). Selected micronutrients and oral and pharyngeal cancer, Int J Cancer.
- Lampeter. EF et al. (1998). The Deutsche Nicotinamide Intervention Study: an attempt to prevent type 1 diabetes. DENIS Group, Diabetes.
- Gong. B et al. (2013). Nicotinamide riboside restores cognition through an upregulation of proliferator-activated receptor-γ coactivator 1α regulated β-secretase 1 degradation and mitochondrial gene expression in Alzheimer's mouse models, Neurobiol Aging.
- Wang. W et al. (2012). Case report of mental disorder induced by niacin deficiency, Shanghai Arch Psychiatry.