Niacin is one of the crucial building blocks for our body. As a water-soluble vitamin, it can only be stored by the body to a limited extent, which makes a regular supply through food necessary. But what makes niacin so special? In this article, you will learn everything you need to know about the effects of niacin, the daily requirement, the best sources and possible consequences of a deficiency.
Vitamin B3 (niacin), is a water-soluble vitamin that belongs to the eight B vitamins. It plays a central role in energy metabolism and is essential for the health of the skin, nerves and psyche.
Niacin comes in two main forms:
Both forms are converted into coenzymes in the body, which support important biochemical processes. The human body can partiallyproduce niacin from the amino acid tryptophan, but an adequate intake of niacin through food is important to meet the body's needs.
Niacin is found in many animal and plant-based foods, although the quantities vary greatly.
The best sources of niacin include:
Foods with a high niacin content:
|
Food |
Niacin per 100 g |
|
Calf's liver |
14,0 mg |
|
Peanuts |
14,0 mg |
|
Tuna |
10,5 mg |
|
Chicken breast |
10,5 mg |
|
Champignons |
4,7 mg |
Although plant foods contain less niacin, the requirement is usually well met with a healthy diet. It is important to note that the body can synthesise niacin from tryptophan, which is particularly important in a high-protein diet.
Niacin is often expressed in niacin equivalents (NE) to account for both directly supplied niacin and niacin synthesised from tryptophan. The conversion factor is as follows:
1 mg niacin is equivalent to 60 mg tryptophan.
Example: a high-protein meal containing 600 mg of tryptophan is equivalent to 10 mg of niacin.
This makes it clear that a high-protein diet in particular can help to meet niacin requirements, even if direct sources of the vitamin are limited.
Niacin is an all-rounder vitamin that plays a key role in many bodily processes.
Niacin is an indispensable component of coenzymes such as NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate). The NAD precursor nicotinamide riboside (NR), a compound known from longevity research, also belongs to the class of B3 vitamins and is crucial for the body's energy supply. NADH (nicotinamide adenine dinucleotide hydride) is the biologically active form of vitamin B3. These coenzymes are responsible for a functioning metabolism, including:
Without sufficient niacin, the body would not be able to obtain the energy it needs from food.
Vitamin B3 contributes to the normal functioning of the nervous system. It supports the formation of neurotransmitters, which are essential for the transmission of signals between nerve cells. A niacin deficiency can therefore lead to neurological disorders and damaged nerves.
Niacin plays an important role in mental health by contributing to normal psychological function.
It contributes to:
A sufficient supply of niacin therefore supports mental resilience and general well-being.
Niacin helps to maintain normal skin by strengthening the skin barrier and improving moisture retention.
Vitamin B3 supports the normal function of the mucous membranes and thus contributes to the functioning of the digestive system. Deficiencies can cause digestive problems such as diarrhoea, constipation, loss of appetite, vomiting or inflammatory diseases of the digestive tract.
Niacin helps to reduce tiredness and fatigue because it is involved in energy metabolism.
The daily requirement for niacin varies depending on gender, age and energy consumption. The reference values of the German Nutrition Society (DGE) are 11-17 mg niacin equivalents per day. The niacin requirement is highest in male adolescents. After that, the requirement decreases with age. In special circumstances, such as during high physical exertion, pregnancy, stress or illness, the need may be increased.
However, the dosages used in practice for general health maintenance or targeted use are often significantly higher. The European Food Safety Authority (EFSA) states the following upper limits for the total daily intake of nicotinamide:
|
Age (years) |
Tolerable upper intake level (UL) for daily niacinamide intake (mg per day) |
|
4-6 |
220 |
|
7-10 |
350 |
|
11-14 |
500 |
|
15-17 |
700 |
|
> 17 (Adults) |
900 |
The maximum level for nicotinamide has been set at 12.5 mg per kg of body weight per day, or about 900 mg per day for adults. This level does not apply during pregnancy or breastfeeding because there are insufficient data for this critical period of life. Maximum levels for children and adolescents have been derived based on body weight.
A niacin deficiency is in developed countries rare, but can occur with an unbalanced diet or certain illnesses. Risk groups include:
Niacin deficiency symptoms only appear when tryptophan metabolism is disturbed at the same time or the protein and vitamin B6 intake is very low.
Signs of early niacin deficiency are unspecific: exhaustion and fatigue, loss of appetite, headaches and irritability.
Severe niacin deficiency leads to pellagra, which is characterised by the following symptoms (the ‘3 Ds’):
Treatment involves a targeted intake of vitamin B3 through dietary supplements or dietary adjustments. In cases of severe deficiency, a doctor should be consulted to determine the correct dosage.
Niacin is found in many foods. The best sources include lean meat, fish, eggs and offal such as liver. Plant-based foods such as whole grains, legumes, mushrooms and green leafy vegetables also contain vitamin B3, albeit in smaller quantities.
Niacin should preferably be taken with meals to optimise absorption. It may be useful to take niacin if there is a proven deficiency, during periods of high physical exertion or to specifically support the nerves and energy metabolism.
Yes, the daily requirement of niacin can usually be easily covered by a balanced diet. A combination of animal and plant-based foods, as well as the conversion of tryptophan to niacin, helps to meet the requirement. However, in the case of increased requirements or existing illnesses, supplementation with niacin food supplements can be useful.
A distinction must be made here between the two forms of niacin.
However, there is no need to fear an overdose with a normal diet, as the niacin levels in normal foods are harmless. The recommended daily dose should not be exceeded when taking food supplements.
Sources:
Gröber, U. Orthomolekulare Medizin. Ein Leitfaden für Apotheker und Ärzte. 2008.
Hahn, A. et al. Ernährung. Physiologische Grundlagen, Prävention und Therapie. 2006.
EFSA. et al. 2024. Overview on Tolerable Upper Intake Levels as derived by the Scientific Committee on Food (SCF) and the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). Version 10. https://www.efsa.europa.eu/sites/default/files/2024-05/ul-summary-report.pdf
Shahbazian, H. et al. 2011. Oral nicotinamide reduces serum phosphorus, increases HDL, and induces thrombocytopenia in hemodialysis patients: a double-blind randomized clinical trial. Nefrologia. 31(1):58-65. https://pubmed.ncbi.nlm.nih.gov/21270914/
Shepherd, J. et al. 2005. European Consensus Panel: Nicotinic acid in the management of dyslipidaemia associated with diabetes and metabolic syndrome: a position paper developed by a European Consensus Panel. Curr Med Res Opin. 21(5):665-82. https://pubmed.ncbi.nlm.nih.gov/15969866/
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