Niacin is vitamin B3, water-soluble, and present across ordinary food — meat, fish, wholegrains, peanuts and fortified cereals among the common sources. The body can also make a small amount from the amino acid tryptophan, so dietary protein contributes indirectly.

Deficiency is rare in the UK in people eating a varied diet, which is the right context for reading a 100% NRV figure: it tops up an intake that is usually already adequate.

Nicotinic acid and the flush

Nicotinic acid causes a distinctive reaction at supplemental doses — skin reddening, warmth, tingling and sometimes itching, usually across the face, neck and chest, starting within about twenty minutes and passing within an hour or two. It is a dilation of small blood vessels. It is not dangerous, and it is extremely uncomfortable if you were not expecting it.

Nicotinamide does not do this

Nicotinamide supplies the same nutrient without the flushing reaction. The two forms are not identical in every respect — nicotinic acid has effects at pharmacological doses that nicotinamide does not share — but as a source of the vitamin at nutritional intakes they do the same job.

We use nicotinamide. A product taken daily, by people who did not sign up for a side effect, should not produce one that is entirely avoidable. And it is checkable: if a label says only “niacin” with no form named, you cannot tell which you have until you take it.

Niacin is one of the few water-soluble vitamins with a meaningful ceiling. Upper intake levels have been set for both forms, and the level for nicotinic acid is far lower than for nicotinamide, precisely because of the flushing effect.

16mg is 100% of the reference intake and sits comfortably below any of those ceilings. It is the third ingredient in this range where the case for the dose is restraint rather than generosity, and the pattern is not an accident: for most vitamins, past the reference intake the returns stop and only the risks continue.

• Niacin contributes to normal energy-yielding metabolism
• Niacin contributes to normal functioning of the nervous system
• Niacin contributes to normal psychological function
• Niacin contributes to the maintenance of normal mucous membranes
• Niacin contributes to the maintenance of normal skin
• Niacin contributes to the reduction of tiredness and fatigue

Note that the claims attach to niacin, not to nicotinamide. The register names the nutrient; the form is a separate matter, which is why our label states both.

They apply from a threshold of 15% of the reference intake. We carry 100%.

• We do not claim niacin does anything for vaginal or intimate health. No such claim exists for it, and we will not imply one by placing an unrelated claim next to intimate-health copy.
• We do not claim nicotinamide is more effective than nicotinic acid. It is better tolerated at these intakes, which is a different and smaller statement.
• We do not claim those six sentences describe what this product does. They describe what the nutrient contributes to, assessed on the nutrient and not on our formulation.
• We do not claim this product treats, prevents or reduces the risk of anything.

What we claim is the composition: 16mg of niacin as nicotinamide, 100% of the Nutrient Reference Value.

Worth knowing

Nicotinamide at 100% of the reference intake is well tolerated and should not cause flushing. If you take a separate niacin supplement, a B-complex or a high-dose multivitamin alongside this one, check which form those use — the totals add up, and nicotinic acid is the form associated with the reaction. If you are managing a condition or taking medication, speak to your GP or pharmacist before adding a supplement.