Better skin and more energy

What is niacin (vitamin B3)?

Niacin, also known as vitamin B3, is a water‑soluble B vitamin made up of several closely related chemical compounds. These include nicotinic acid and nicotinamide, which can be converted into each other in the body as needed.

The human body can obtain niacin from food but can also synthesise it if enough tryptophan is available – an amino acid that is important, among other things, for serotonin production. After absorption through the digestive tract, particularly the small intestine, the vitamin enters the bloodstream and is used by various organs, with the liver acting as a storage site. Excess amounts are excreted in the urine.

The bioavailability of niacin depends on the food source. In animal products it is mainly present as nicotinamide and can be almost fully utilised. Plant foods, by contrast, usually contain nicotinic acid that is often bound to other molecules, reducing the body's ability to absorb it. Besides its role in energy production, niacin is also involved in forming other important molecules that regulate many bodily processes and contribute to overall wellbeing.

What does niacin do in the body?

Niacin plays a key role in the body by fulfilling numerous vital functions, notably supporting the nervous system. It helps form myelin sheaths that surround nerve fibres and improve signal transmission. A deficiency in niacin can therefore lead to neurological symptoms such as tingling or difficulties with concentration.

The vitamin also has a central role in energy metabolism, as it is part of NAD and NADH, two coenzymes involved in cellular energy production. These molecules promote the conversion of nutrients into energy, which is particularly important for physical and mental performance. Niacin also affects blood sugar regulation by forming, together with chromium, the glucose tolerance factor (GTF), which supports insulin action and improves glucose uptake. This helps stabilise blood glucose levels.

The vitamin also has a protective effect on various organs. Particularly high concentrations are found in the heart, liver, kidneys and immune cells, suggesting it is necessary for their function. For example, niacin supports the liver in detoxification and helps protect the skin by shielding cells from UV radiation and promoting repair of DNA damage. Studies show that regular intake of niacin can reduce the risk of UV‑related skin damage and skin cancer.

Furthermore, niacin is important in regulating blood lipids. In the form of nicotinic acid it can lower triglycerides and raise “good” HDL cholesterol, thereby helping to prevent cardiovascular disease. An anticoagulant effect has also been observed, since it lowers fibrinogen levels associated with atherosclerosis and thrombosis risk.

Finally, the vitamin shows potential in the field of mental health. Research indicates that nicotinamide may have supportive effects in certain psychiatric conditions by reducing inflammatory processes and improving cellular function in the brain.

What is a niacin flush?

Niacin flush is a physical reaction that can occur when the body takes high doses of niacin, particularly in the form of niacinamide. The skin may redden and you may experience a warm sensation, especially on the face and upper body. This happens when niacin reacts with certain skin proteins, causing blood vessels to dilate and blood flow to increase. In some cases, mild tingling or itching may occur. Despite the discomfort, the niacin flush is harmless and usually subsides within one to two hours.

Although niacin flush often occurs when taking high doses of niacin, particularly over 500 mg, it does not cause permanent damage. Gradually increasing the dose and taking niacin with meals can help reduce the intensity of the reaction. There are also specific forms of niacin, such as inositol nicotinate, that are less likely to trigger a flush because they are metabolised more slowly in the body.

Symptoms of the niacin flush often diminish over time as the body becomes accustomed to higher doses. However, people taking high doses of niacin to lower cholesterol should do so under medical supervision, as very high doses can cause side effects such as low blood pressure or liver problems.

What causes a vitamin B3 deficiency?

A vitamin B3 deficiency can be caused by various factors but is relatively rare in industrialised countries. The body can make vitamin B3 from the amino acid tryptophan if certain conditions are met. A deficiency in vitamin B6 or protein can impair the conversion of tryptophan to niacin and lead to a deficiency. In such cases serious symptoms such as skin inflammation, nerve damage or psychiatric disorders can occur.

One of the most common causes of niacin deficiency is a restricted diet. People who eat an unbalanced diet or consume foods low in tryptophan and niacin – for example, a diet based mainly on maize – are particularly at risk. This can lead to pellagra, a condition caused by a simultaneous deficiency of niacin and tryptophan that affects the skin, the digestive tract and the nervous system.

There are also medical factors that increase the risk of vitamin B3 deficiency. These include liver diseases such as cirrhosis, alcohol use disorder, chronic diarrhoea and Hartnup syndrome, which impairs tryptophan absorption. Certain medications, such as the antibiotic isoniazid, can also reduce the body's own production of niacin. People with alcohol dependence are especially vulnerable, as alcohol can significantly disrupt nutrient absorption.

How much niacin is needed per day?

The daily requirement for niacin varies by age, sex and energy expenditure. In general, requirements are highest in adolescents aged 15 to 19 years, at 17 mg niacin equivalents per day. In adults the requirement is 12 mg for women and 15 mg for men, decreasing after age 51 to 11 mg for women and 14 mg for men.

Certain life stages such as pregnancy and breastfeeding increase niacin requirements. In the second trimester of pregnancy the recommended amount is 14 mg per day, and in the third trimester and during breastfeeding it is 16 mg. Certain conditions, such as alcoholism or digestive disorders, may also raise niacin needs. Adequate intake is generally achievable through a balanced diet, so supplements are not necessary in most cases.

How to prevent a niacin deficiency: practical tips

• The highest concentration of niacin is found in animal foods, and our bodies can utilise this form of the vitamin more efficiently than that from plant sources.
• Foods particularly rich in niacin include meats (lean beef, veal and pork, poultry), offal and fish (anchovies, tuna, salmon, mackerel), which also contain tryptophan.
• Calf liver contains 19 mg niacin per 100 g and is also rich in vitamin A and iron. Roast or braise liver to make a tasty dish and boost your niacin intake.
• Vegans should include bread, peanuts, mung beans, cashews, legumes, dates and other dried fruits as well as mushrooms in their daily diet.
• Enjoy a handful of raw peanuts daily to benefit from their high niacin content. They provide 20.7 mg niacin per 100 g and supply important nutrients.
• Peas are a good niacin source with 6.3 mg per 100 g. Add them fresh or frozen to risottos, pasta or stir‑fries to enrich your meals.
• Kidney beans contain 5.8 mg niacin per 100 g and are a valuable source of fibre and protein. Use them in chilli, stews or salads.
• Coffee lovers can expect about one to two milligrams of nicotinic acid per cup, as roasted coffee has a relatively high niacin content.
• A breakfast of two slices of wholegrain bread with peanut butter and two cups of coffee can cover the daily requirement for vitamin B3, as can 25 g of peanuts and 100 g of oyster mushrooms.
• Cocoa powder, with 8.1 mg niacin per 100 g, is a tasty addition. Enjoy it as a cocoa drink or use it in baking to benefit from its health properties.
• Because vitamin B3 is water‑soluble, some is lost into the cooking water when vegetables are boiled. It is advisable to reuse the cooking water or to cook vegetables gently, for example with a steamer.
• Nicotinic acid can cause vasodilation with “flush” symptoms (warmth, local redness and itching) and gastrointestinal discomfort, whereas nicotinamide usually has no such side effects.
• If you take medications such as antidiabetics or blood thinners, or have risk factors for niacin deficiency, consult your doctor about the appropriate dose of niacin supplements.
• A balanced diet promotes niacin synthesis and supports metabolism, preventing skin changes and the consequences of anorexia. In therapy, niacin supplementation may also be useful to help prevent disease and dementia.

Niacin is central to energy metabolism and skin health. Adequate intake contributes to general wellbeing and prevents deficiency symptoms.