E375 (Nicotinic acid, niacin)

E375 refers to nicotinic acid, one of the forms of vitamin B3. The name often creates confusion because it sounds close to nicotine, but it is not nicotine and it does not make a food tobacco-like. It is a water-soluble vitamin factor involved in the formation of NAD and NADP, two coenzymes that sit at the center of cellular energy metabolism. In the E-number context, E375 is notable less as a classic texture, color, or preservation additive and more as a nutrient-related and historical entry used in fortification or specialized formulations.

What the substance is

Nicotinic acid belongs to the niacin family together with nicotinamide and related compounds that the body can convert into active vitamin B3 forms. Its main biochemical role is connected with electron transfer. NAD participates in reactions that help cells obtain energy from glucose, fatty acids, ketone bodies, alcohol, and amino acids. NADP is especially important for reductive reactions, antioxidant systems, and synthesis of many molecules.

Because of this role, vitamin B3 is not relevant to only one organ. Skin, mucous membranes, the nervous system, the liver, muscles, and the digestive tract all depend on adequate niacin status. Severe deficiency is historically associated with pellagra and with problems involving skin, digestion, and the nervous system. That does not mean that every product listing E375 is a therapeutic source of niacin. The code shows that the substance is present; it does not prove a clinical dose, a useful supplement form, or a health benefit from one serving.

How it differs from a niacin supplement

Vitamin B3 naturally present in food, a fortified food, and a high-dose nicotinic acid supplement are very different situations. Food-level amounts usually belong to normal nutrition. Pharmacological doses of nicotinic acid can influence lipid metabolism, cause flushing, warmth, redness, itching, and sometimes a drop in blood pressure. In unsuitable use they may also affect liver enzymes, glucose control, or uric acid.

For that reason, E375 should not be read as an invitation to use large doses of vitamin B3 on one’s own. If deficiency correction is needed, the decision should consider diet quality, symptoms, medication, alcohol intake, digestive disorders, and laboratory context. Extra caution is reasonable in liver disease, gout, unstable glucose metabolism, active ulcer disease, low blood pressure, and when a person takes medicines that may interact with niacin effects or side effects.

Where vitamin B3 comes from in food

A normal diet can provide vitamin B3 without relying on E-numbers. Niacin and its precursors are found in meat, poultry, fish, liver, eggs, nuts, seeds, and some dairy foods. The body can also make some niacin from tryptophan, but this pathway depends on protein status and on nutrients such as vitamin B6, vitamin B2, and iron. A low-protein or very monotonous diet can therefore weaken the practical supply even if calories seem sufficient.

In low-carbohydrate eating, vitamin B3 intake is usually not a problem when the menu is based on whole foods: fish, meat, eggs, organ meats, seafood, nuts, and fermented dairy if tolerated. Problems are more likely when the diet becomes extremely restrictive, low in calories, low in protein, or dominated by processed replacement products. Alcohol, chronic digestive inflammation, and poor absorption can also change the picture more than carbohydrate restriction itself.

How to read E375 on a label

When E375 appears in an ingredient list, it is useful to separate the technological fact from the nutrition conclusion. Nicotinic acid is not sugar, starch, maltodextrin, or a hidden carbohydrate source. However, the product that contains it may still be sugary, flour-based, ultra-processed, or designed as a fortified drink or powder. The whole formula matters: carbohydrate amount, sweeteners, protein, fat quality, vitamin dose, intended use, and serving size.

For keto and LCHF, E375 itself is usually not a reason to reject a food. The reason it is present matters more. If it is part of a sweet drink with sugar, the sugar is the issue. If it is part of a nutrient mix without meaningful carbohydrate load, the questions become dose, tolerance, need, and whether the product fits the person’s overall diet. A single E-number cannot turn a weak product into a nutrient-dense food.

Safety and common misunderstandings

The first common mistake is treating nicotinic acid as harmless at any dose just because it is a vitamin. In food-level amounts, vitamin B3 is essential; in high supplemental amounts, nicotinic acid can have drug-like effects. Flushing after nicotinic acid is not the same as a classic allergy, but it may be unpleasant and sometimes risky for people with unstable blood pressure or strong vascular reactions. Nicotinamide behaves differently, but it is a different vitamin B3 form.

The second mistake is confusing nicotinic acid with nicotine. The historical chemical name does not make the ingredient addictive and does not connect the food with smoking risks. The third mistake is assuming that E375 makes the whole product healthy. Niacin matters, but the value of a food depends on the full composition, processing level, nutrient density, and how often it replaces better foods.

Practical takeaway

E375 is best understood as a specific form of vitamin B3. In everyday eating, it is usually better to obtain niacin together with complete protein, minerals, and other B vitamins from real foods than to chase it as a code on labels. In supplements or medical-dose products, nicotinic acid deserves more caution because its effects go beyond simple nutritional fortification. For low-carbohydrate diets, it is neutral from a carbohydrate point of view, but it is not by itself a quality seal for the product.