Niacin: what you should know about the vitamin
Anyone who is physically active needs a well-functioning (energy) metabolism. To ensure this, an adequate intake of B vitamins is essential. In today’s blog post we explain what role niacin plays.
What is niacin?
Niacin counts to 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 converted into one another in the body.
The vitamin can also be produced from tryptophan in the body. Therefore, it is 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 taken in through food. So there were earlier considerations as to whether the vitamin should be counted among the amino acids.
What functions does niacin have?
Niacin is involved in numerous metabolic processes involved in the human body. The functions affect 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 fatty acid, carbohydrate and protein metabolism a. The vitamin is also important for the skin, muscle tissue, the nervous system and for the regulation of blood sugar .
NAD and NADP are also hydrogen carriers. NAD-dependent dehydrogenases are particularly found in mitochondria. Here they play a special role in the respiratory chain for energy production. In the cytosol there are NADP-dependent dehydrogenases, which are important in the synthesis of fatty acids and cholesterol . These also play a special role in the pentose phosphate pathway. This pathway is the most important source of NADPH, which is involved in the antioxidative defense .
“Niacin lowers the concentration of the C-reactive protein ( CRP), which is an inflammation marker (Hoffer A., Saul A. and Foster H.). “
Amounts of 1 g or more of nicotinic acid per day have pharmacological effects . This lowers LDL cholesterol and triglycerides in humans, while increasing HDL in the blood. As a result, niacin is often used to lower elevated lipid concentrations in the blood . Since increased lipid concentrations represent a risk factor for cardiovascular diseases , supplementation makes sense especially in this area. Note: An intake of nicotinamide 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 seems to have a life-extending effect . This is shown by a study using the example of roundworms: the roundworms that niacin received through food lived a tenth longer than the control group.
Niacin in sports
Athletes in particular need more micronutrients, as large amounts are lost in sweat or urine. A deficiency in micronutrients leads to a decrease in performance, an increased susceptibility to infection and the risk of injury.
As described above, niacin has positive effects on the energy metabolism. It also supports the burning of carbohydrates and fats . A sufficient intake of the vitamin has a supportive effect on fatigue, physical performance and the ability to coordinate.
It has recently been known that niacin increases the proportion of oxidative type I muscle fibers and to reduce glycolytic type II muscle fibers . This is likely to lead to an upregulation of genes involved in fatty acid oxidation and the citrate cycle. The changes in the muscle fiber composition should be accompanied by improved endurance performance , since the type I muscle fibers are particularly enduring.
A doctoral thesis deals with this topic. The effect of endurance training, a high dose of niacin (cf. in human medicine for the therapy of dyslipoproteinemia) and a combination of endurance training and a high dose of niacin on endurance performance and the composition of muscle fibers was investigated in mice. For this purpose, the mice were divided into four groups. Two groups received endurance training and an adequate amount of the vitamin and 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 could be shown that the mice with endurance training and high niacin supplementation had an increased endurance performance . However, niacin supplementation alone had no effect. The reason how niacin affects endurance performance is 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 that are involved in carnitine uptake or biosynthesis and thus improve the reduced carnitine status of obese rats. However, further research is necessary here.
Content in food
Niacin is contained in meat, fish, offal such as liver, whole grain products and vegetables like kohlrabi and peas . In foods of animal origin, the vitamin occurs mainly as nicotinic acid amide (in the form of NAD or NADP). Since the vitamin can be stored in the liver in limited quantities in the form of NAD (reserve sufficient for 2-6 weeks), liver is a good source. Nicotinic acid is predominantly found in plant-based foods. Since niacin is mainly bound to macromolecules in cereals, it is more difficult to split; the bioavailability is only around 30%. The vitamin is released when the food is roasted or alkaline solutions are used. Niacin is also released in coffee beans through roasting. 100 g roasted coffee beans contain 15 mg of the vitamin.
A conversion of the vitamin from tryptophan – as already mentioned – is possible. However, you need 60 mg of this amino acid to make 1 mg of niacin . It should be noted that the vitamin is only formed in sufficient quantities if there is an excess of tryptophan. If the intake is sufficient, tryptophan is used for protein synthesis .
How much of the vitamin should be consumed per day?
The recommended one According to the German Nutrition Society in Germany, intake 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 with doses of 1 g or more daily.
Are high doses dangerous?
Studies on the cholesterol-lowering effect with gifts 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 reddening of the skin can occur, but these will disappear after a few days / weeks. However, taking the substance nicotinamide does not lead to either of the two symptoms, which is why nicotinamide is used more often in dietary supplements, as in our Sport Essentials . Here you get to the product.
Excess niacin is either stored in the liver or methylated and excreted via the kidneys as N1-methylnicotinamide.
How is a deficiency noticeable?
The symptoms of a niacin deficiency are initially very uncharacteristic ; they are expressed, for example, by insomnia and loss of appetite. In the advanced stage, the typical three symptoms such as diarrhea, dementia and dermatitis of the Pellagra disease appear. For example, skin that is exposed to light has burning and itchy spots that can swell, harden and even blister. Numbness can also occur. The classic Pellagra is only known in connection with a protein or tryptophan deficiency. This disease is particularly common in countries that have a high corn consumption . This is characterized by the low content of tryptophan in maize and the non-usable form of niacin (niacytin) it contains. Therefore, in Central America tortillas are treated with alkali to prevent deficiency.
A niacin deficiency is Very rare in Germany . A vitamin deficiency can only occur through increased alcohol abuse and severe diarrhea. A vitamin B6 deficiency can also be responsible for a niacin deficiency.