Niacin: What you should know about the vitamin
Active athletes need a well-functioning (energy) metabolism. To ensure this, a sufficient supply of B vitamins is essential. We explain what role niacin plays in this in today's blog post.
Table of contents:
- What is niacin?
- What are the functions of niacin?
- Niacin in the sports sector
- How does a niacin deficiency make itself felt?
What is niacin?
Niacin is one of the eight B vitamins. In the past, the vitamin was also known as vitamin B3, as it was the third water-soluble vitamin to be discovered. Niacin is a collective term for the two substances nicotinic acid and nicotinamide (don't worry: the two substances have nothing to do with nicotine!). Both substances have the same effect, both quantitatively and qualitatively, as they can be metabolised in the body.
The vitamin can also be produced from tryptophan in the body. It is therefore not a vitamin in the classic sense, as unlike the other water-soluble vitamins, it can also be produced by the body itself and does not only have to be absorbed through food. There were therefore earlier considerations as to whether the vitamin should be categorised as an amino acid. amino acids.
What functions does niacin have?
Niacin is involved in numerous metabolic processes in the human body. Its functions influence almost the entire human metabolism. Niacin is active in the form of the two substances NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate) as a coenzyme component of various dehydrogenases.
These intervene in energy production as well as in fat, carbohydrate and protein metabolism. The vitamin is also important for the skin, muscle tissue, the nervous system and the regulation of blood sugar.
NAD and NADP are also hydrogen carriers. NAD-dependent dehydrogenases are found in mitochondria in particular. Here they play a special role in the respiratory chain for energy production. NADP-dependent dehydrogenases are found in the cytosol and are important in the synthesis of fatty acids and cholesterol. They also play a special role in the pentose phosphate pathway. This pathway is the most important source of NADPH, which is involved in theantioxidant defence.
„Niacin lowers the concentration of C-reactive protein (CRP), which is an inflammatory marker (Hoffer A., Saul A. and Foster H. (2018)).“
Amounts from 1 g nicotine per day have pharmacological effects. In humans, LDL cholesterol and triglycerides are lowered, while HDL is increased in the blood. As a result, niacin is also frequently used to reduce elevated lipid concentrations in the blood. As elevated lipid concentrations are a risk factor for cardiovascular disease, supplementation is particularly useful in this area. Note: Nicotinamide intake has no cholesterol-lowering effects.
The vitamin is also said to help with diseases such as depression, ADHD, Alzheimer's, arthritis and schizophrenia. Furthermore, the vitamin appears to have a life-prolonging effect. This was shown in a study using the example of threadworms: the threadworms that received niacin through their food lived a tenth longer than the control group.Niacin in the sports sector
Especially athletes need more micronutrients, as large amounts are lost in sweat or urine. A lack of micronutrients leads to a decrease in performance, increased susceptibility to infection and risk of injury.
Niacin has positive effects on energy metabolism as described above. It also supports the burning of carbohydrates and fats. A sufficient intake of the vitamin therefore has a supportive effect on fatigue, physical performance and coordination.
Niacin has recently been shown to increase the proportion of oxidative type I muscle fibres and reduce the glycolytic type II muscle fibres. This probably leads to an upregulation of genes involved in fat oxidation and the citrate cycle. The changes in muscle fibre composition are said to be associated with improved endurance performance, as type I muscle fibres are particularly enduring.
A doctoral thesis deals with precisely this topic. The effect of endurance training, high niacin administration (cf. in human medicine for the treatment of dyslipoprotein disorders) and a combination of endurance training and high niacin administration on endurance performance and muscle fibre composition in mice was investigated. For this purpose, the mice were divided into four groups. Two groups received endurance training and an adequate amount of the vitamin as well as an increased dose of niacin. The other two groups each received a moderate dose of niacin and an increased dose of niacin. After six weeks, it was shown that the men with endurance training and high niacin supplementation had increased endurance performance. However, niacin supplementation alone showed no effect. The reason why niacin influences endurance performance is therefore still unknown.
A study by Couturier et al. (2014) also shows that niacin administration in obese rats leads to an increased carnitine concentration in the body. Niacin is said to stimulate genes involved in carnitine uptake and biosynthesis and thus improve the reduced carnitine status of obese rats. However, further research is still needed in this area.Content in food
Niacin is found in meat, fish, offal such as liver, wholemeal products and vegetables such as kohlrabi and peas. In animal foods, the vitamin is mainly found as nicotinamide (in the form of NAD or NADP). As the vitamin in the form of NAD can be stored in the liver in limited quantities (reserves last for 2-6 weeks), liver is a good source. Nicotinic acid is predominantly found in plant foods. As niacin in cereals is mainly bound to macromolecules, it is more difficult to break down; the bioavailability is only around 30 %. However, the vitamin is released when food is roasted or alkaline solutions are used. Niacin is also released in coffee beans through roasting. For example, 100 g of roasted coffee beans contain 15 mg of the vitamin.
A conversion of the vitamin from tryptophan - as already mentioned - is also possible. However, 60 mg of this amino acid is required to produce 1 mg of niacin. It should be noted that the vitamin is only produced in sufficient quantities if there is a tryptophan surplus. If the intake is sufficient, tryptophan is utilised for protein synthesis.
.How much of the vitamin should be consumed per day
According to the German Nutrition Society, the recommended intake in Germany is 16 mg per day for men and 13 mg for women. The therapeutic amount is over 100 mg per day. Pharmacological effects are seen at doses from 1 g per day.
Are high doses dangerous?
Studies on the cholesterol-lowering effect with doses of 3-6 g nicotinic acid per day show that the vitamin is non-toxic in high doses. At higher doses, only a feeling of warmth and skin irritation may occur, which disappear after a few days/weeks. However, taking the substance nicotinamide does not lead to either of these symptoms, which is why nicotinamide is more commonly used in dietary supplements, such as in our Sport Essentials. Here is the link to the product.
Excess niacin is either stored in the liver or methylated and excreted via the kidneys in the form of N1-methylnicotinamide.
How does a niacin deficiency become noticeable?
The symptoms of a niacin deficiency are initially very uncharacteristic, for example through a lack of sleep and appetite. At an advanced stage, the three typical symptoms of the disease pellagra, such as diarrhoea, dementia and dermatitis, appear. For example, burning and itchy areas can be found on the skin that is exposed to light, which can swell, harden and even form blisters. Numbness can also occur. Classic pellagra is only known in connection with a protein or tryptophan deficiency. This disorder is particularly common in countries with a high consumption of maize. This is characterised by the low content of tryptophan in maize and the non-usable form of niacin (niacytin) it contains. This is why tortillas in Central America are treated with alkali to prevent a deficiency.
Niacin deficiency is very rare in Germany. A deficiency of the vitamin can only occur as a result of increased alcohol abuse and heavy drinking. A vitamin B6 deficiency can also be responsible for a niacin deficiency.
Sources:
- Hoffer A., Saul A. and Foster H. (2018): Niacin in the treatment. ABA Verlag UG, Berlin.
- Biesalski H. K. and Grimm P. (2007): Taschenatlas Ernährung. Thieme Verlag, 4th edition, Stuttgart.
- https://1a-wellness.ch/mobile/smartphone/downloads/mikronaehrstoffe.pdf
- https://www.germanjournalsportsmedicine.com/fileadmin/content/archiv2008/heft03/Standard%20Hipp.pdf
- https://www.dge.de/wissenschaft/referenzwerte/niacin/
- https://www.deutsche-apotheker-zeitung.de/daz-az/2008/daz-10-2008/die-haut-braucht-niacin
- https://pubmed.ncbi.nlm.nih.gov/24267720/
- https://pubmed.ncbi.nlm.nih.gov/25012467/
- https://pubmed.ncbi.nlm.nih.gov/24010567/
- Kynast A. M. (2017): Influence of niacin on the endurance performance of mice. Doctoral thesis, Justus Liebig University Gieät Gie&sz;en.