Niacin (Vitamin B3): Effect, Deficiency and Diet

foods with niacin

© Getty Images/Liudmila Chernetska

The vitamin niacin is also known by the names of nicotinic acid and vitamin B3 or vitamin PP. Niacin is essential for several bodily functions, such as energy metabolism. However, if too much niacin is taken, the vitamin can also have side effects. You can read more about the effects of niacin, symptoms of deficiency and overdose, and foods rich in vitamin B3 here.

What is niacin?

Niacin is a water-soluble vitamin that is ingested through food and is formed in the human body, more precisely in the liver. To do this, the body needs the amino acid tryptophan. Strictly speaking, niacin is a generic term for different chemical compounds. These include nicotinic acid and nicotinamide.

Niacin belongs to the group of B vitamins, which is why the now obsolete name vitamin B3 is still used in common parlance. The term vitamin PP stands for “pellagra prevention”, that is, to prevent pellagra. This is a condition that can result from a deficiency of niacin.

Niacin: vitamin action

Niacin, more precisely nicotinamide, is usually present in the human body as a component of the two coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP+) and is contained in all living human cells. Particularly high concentrations are present in the kidneys, liver, and adipose tissue.

Niacin plays a particularly important role in the body’s energy supply because, as a component of NAD and NADP+, it is involved in protein metabolism as well as fat and carbohydrate metabolism.

In addition to its central role in energy metabolism, niacin is important for the recovery of our body. It is particularly important for the regeneration of muscles, nerves, DNA and skin. Also, niacin promotes the formation of messenger substances in the brain, with the help of which information is transported from one nerve cell to another. It plays a role in the proper functioning of the nervous system.

Niacin: what is the daily requirement?

Since the vitamin can be partially produced in the liver itself, it is difficult to estimate the daily requirement that must be ingested through food. Also, some foods contain the amino acid tryptophan, which the body uses to make vitamin B3. For this reason, the term “niacin equivalents” is also used to indicate the niacin content of foods.

Of Niacin daily requirementthat should be ingested through food, differs slightly according to age and gender.

Adults between the ages of 19 and 25 have the greatest need. Men of this age should consume 16 milligrams of vitamin B3 per day and women 13 milligrams.

Men between the ages of 25 and 65 have a daily requirement of 15 milligrams, after that it drops to 14 milligrams. Women between the ages of 25 and 51 should daily 12 milligrams Take niacin, after that eleven milligrams is enough.

In general, the average daily dose taken in Germany is higher than required. However, an overdose as part of a normal diet is not possible, so a slightly higher intake is harmless to health.

Foods with vitamin B3

Meat, fatty fish such as salmon or tuna, and organ meats are especially rich in vitamin B3. But some plant-based foods can also be high in niacin. These include peanuts, mushrooms, potatoes, coffee or whole grain products. Vitamin B3 is also found in dairy products.

For example, there is as much niacin in the following foods (per 100 grams):

  • Beef liver: 15 milligrams
  • Beef muscle meat: 7.5 milligrams
  • Whole grain rye: 5.1 milligrams
  • Peas: 0.3 milligrams

According to the German Nutrition Society (DGE), the highest possible daily requirement of 15 milligrams of niacin can be met, for example, by eating 45 grams of peanuts and 100 grams of fried oyster mushrooms.

In general, the body is better able to use niacin that comes from animal products.

Tip: Like biotin or pantothenic acid, niacin is one of the water-soluble vitamins. Since it is easily transferred to the cooking water during cooking, the cooking water should be reused if possible.

Causes of a vitamin B3 deficiency

A deficiency of the vitamin niacin is relatively rare in industrialized countries because, as already mentioned, it can not only be ingested through various foods, but is also formed in the body from the amino acid tryptophan. Approximately one milligram of niacin is produced from 60 milligrams of tryptophan.

One possible cause of niacin deficiency is not getting enough niacin through food. Inadequate intake is particularly common in groups of people for whom maize is a staple food. Because the form of nicotinic acid contained in corn cannot be used by the body.

In rare cases, diseases can also cause a vitamin B3 deficiency. This includes:

In addition, a niacin deficiency can also occur if you consume too little protein. So not enough tryptophan can be converted to niacin. Additionally, a vitamin B6 deficiency can also result in a niacin deficiency, because vitamin B6 is necessary for the conversion of tryptophan to niacin.

Niacin deficiency symptoms

If a deficiency is suspected, the level of niacin in the blood serum can be determined. Some typical symptoms can also help identify a vitamin B3 deficiency.

The first signs of a niacin deficiency are:

  • tiredness and weakness
  • inflammation in the gastrointestinal tract
  • depressed mood and irritability
  • skin inflammation
  • Diarrhea
  • inflammation of the tongue
  • nerve inflammation

Furthermore, as a result of niacin deficiency, disease pellagra Appear. This is mainly characterized by changes in the skin: pellagra causes an itchy reddish rash that can also be accompanied by swelling, blisters and hardening of the skin. Diarrhea and dementia are other typical symptoms of the disease.

Niacin: Overdose Side Effects

The vitamin niacin usually only has side effects if taken in large amounts. The recommended daily dose is a maximum of 15 milligrams, depending on age and gender. As already mentioned, an overdose of niacin through food consumption is almost impossible. However, there are special preparations, dietary supplements, or foods fortified with vitamin B3 that can be used to supply the body with additional niacin and can lead to an overdose.

The possible consequences of taking too much niacin are:

  • Flush (skin flushing and redness)
  • urticaria
  • Diarrhea
  • nausea and vomiting
  • Liver damage

Higher doses of niacin can also affect blood sugar. Due to potential side effects, niacin supplements and niacin-fortified foods should only be taken on medical advice.

Medicinal use of niacin

Niacin has been shown to have a positive effect on cholesterol levels: it increases “good” HDL cholesterol and lowers “bad” LDL cholesterol. However, due to its side effects, especially flushing, niacin has rarely been used to lower cholesterol levels. To avoid flushing as a side effect, niacin medications were eventually combined with a so-called flush inhibitor (laropiprant).

Because statins have a better risk-benefit ratio in treating high cholesterol, they are now used as an alternative to niacin supplements. The use of both active ingredients was also not proven. In a comprehensive study involving more than 3,000 people at increased risk for cardiovascular disease, no health benefits were seen from taking niacin supplements in combination with statins. Instead, there were frequent side effects.

For this reason, in 2013 a drug that combined statins with vitamin B3 was withdrawn from the market. Niacin preparations are now only used in rare cases to treat high cholesterol levels.

Nicotinic acid medications are also used to treat what is known as Wernicke’s encephalopathy, a central nervous system disorder caused by chronic alcohol abuse.

Updated: 05/27/2022

Author: Kathrin Mehner, Medical Editor | Jasmin Rauch, medical editor


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