Vitamin B3, or niacin, is important for your health. It helps convert food into energy, contributes to the normal function of your nervous system, helps reduce tiredness and fatigue, and supports normal skin. Here's what vitamin B3 does, where to find it, and when a supplement might help.
What does vitamin B3 do?
Like many of the B vitamins, niacin is central to converting the food you eat into usable energy – so it contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. It also contributes to the normal function of the nervous system, normal psychological function, and the maintenance of normal skin and mucous membranes.
One quirk sets niacin slightly apart from its B-vitamin siblings: your body can make a small amount of it by itself, from an amino acid called tryptophan (the same one often associated with turkey). That said, this home-made supply only goes so far, and niacin is water-soluble, so your body doesn't store it. The practical result is that food remains your main and most reliable source.
The two forms of niacin
Niacin comes in two main forms: nicotinic acid and niacinamide (also called nicotinamide). Niacinamide is the one you'll often see on the ingredients list of skincare products, where it works as a topical cosmetic ingredient – a different job from taking niacin as a food supplement. If it's the skincare side you're after, explore our niacinamide skincare collection. This article is about vitamin B3 as a supplement, which supports normal skin from within as part of your overall nutrition.
What foods are high in vitamin B3?
You'll find niacin in a wide variety of foods. Good sources include red meat, poultry, fish, brown rice, nuts, seeds, legumes, bananas and fortified cereals. For most people, eating a range of these makes getting enough B3 straightforward.
The NHS recommends approximately 16.5mg a day for men and 13.2mg a day for women. Niacin requirements can vary a little depending on factors like your age, but for the majority of people a balanced diet comfortably covers the daily amount.
Should I take a vitamin B3 supplement?
Most people get all the niacin they need from food, so a supplement is really there for those whose diets fall short – for example a very limited or restricted diet. In those cases, a B3 supplement, or a vitamin B complex that includes it, can be a simple way to keep your daily intake steady.
Niacin is one nutrient where it's genuinely worth being thoughtful about dose. Unlike some water-soluble vitamins where excess is simply passed out without fuss, taking niacin in large amounts can cause side effects – the best known is "niacin flush", a temporary warmth and redness of the skin – and very high doses shouldn't be taken casually. This is why high-dose niacin products should only ever be used under the guidance of a healthcare professional.
That advice goes double in pregnancy: if you're pregnant or planning to be, speak with a healthcare professional before taking a B3 supplement, rather than self-managing. For everyday nutritional top-up at normal levels, though, B3 is a well-understood and widely used supplement.
Explore our range of vitamin B3 supplements to support normal energy release, skin and nervous system function.