Vitamin B3

Our bodies need a special kind of food.

This food helps us stay well. We can get it from meat and fish. We can also find it in nuts and seeds. Some breads even have it added in.

Without this food, people can get very sick. They might feel very tired. They might also get a red rash on their skin. This special food is very important for us to live.

Vitamin B3 is a group of nutrients. It has three different forms. These forms are nicotinic acid, nicotinamide, and nicotinamide riboside.

Your body turns these forms into something called NAD. NAD is a helper that helps your cells work. It is needed for human life. You cannot make NAD without vitamin B3 or an amino acid called tryptophan. Tryptophan is a building block for proteins.

You can find vitamin B3 in many foods. Meat and poultry have it. Red fish like tuna and salmon are good sources too. You can also find it in nuts, seeds, and legumes. Some foods have it added in. This is called fortification.

If you do not get enough vitamin B3, you can get sick. This sickness is called pellagra. It can cause skin sores and mouth problems. It can also make you feel very tired or confused. Doctors often use nicotinamide to treat this. It helps without making your skin turn red or feel hot. Scientists even found vitamin B3 in space on meteorites!

Vitamin B3 is a family of nutrients that helps our bodies stay alive. It includes three different forms called vitamers. These are nicotinic acid, nicotinamide, and nicotinamide riboside. Our bodies must turn these forms into a helper called NAD. NAD is a coenzyme that helps cells work in many ways. It is used in DNA repair and moving calcium. Humans cannot make NAD on their own without vitamin B3 or tryptophan.

To understand how it works, think of NAD as a tiny worker in a factory. This worker helps with important tasks like glycolysis and the Krebs cycle. These are ways our bodies turn food into energy. The vitamin enters the body and is converted into NAD. Once it is NAD, it can help repair DNA. It also helps move calcium where it needs to go. Without these steps, our cells would not function correctly.

Learning about these nutrients has taken a long time. Scientists identified nicotinamide riboside as a form of B3 in 2004. In 1942, the United States government gave specific names to these vitamins. They used the names niacin and niacinamide. They did this so people would not confuse them with nicotine. These names were added to a special dictionary in 1961. This helped doctors and scientists talk about them clearly.

There are many important facts about where B3 comes from. You can find it in meat, poultry, and red fish like tuna or salmon. It is also in nuts, seeds, and legumes. Some foods are fortified, which means B3 is added to them. Many countries add niacin to wheat flour to keep people healthy. If people do not get enough, they can get a disease called pellagra. This disease causes skin sores, headaches, and tiredness.

Vitamin B3 is even found in places far beyond our Earth. Scientists have detected nicotinic acid and nicotinamide in space. They found these in meteorites called carbonaceous chondrite. They also found them in samples from asteroids named Ryugu and Bennu. This shows that the building blocks of life exist in the stars. Just like the food on your plate, these nutrients are part of the wider universe. It is amazing to think that space holds the same things our bodies need.

Vitamin B3 is a vital family of nutrients required for human life. It consists of three distinct forms, known as vitamers: nicotinic acid, nicotinamide, and nicotinamide riboside. These vitamers are essential because the human body cannot produce them on its own. Instead, the body must obtain them through diet or use the amino acid tryptophan to create them. Once consumed, all three forms are converted into a critical molecule called nicotinamide adenine dinucleotide, or NAD. NAD is a coenzyme that serves as a fundamental building block for many biological processes.

To understand how vitamin B3 works, we must look at the role of NAD. NAD and its phosphorylated version, NADP, act as essential helpers in various chemical reactions. They are used in transfer reactions that assist with DNA repair and calcium mobilization. Furthermore, NAD plays a central role in human metabolism. It acts as a coenzyme in two major energy-producing pathways: glycolysis and the Krebs cycle. These processes allow our cells to convert food into the energy needed to function. Without these specific chemical steps, our cellular machinery would fail.

There are important differences between the specific vitamers of B3. While nicotinic acid and nicotinamide share the same vitamin activity, they behave differently in the body. Nicotinic acid has pharmacological and lipid-modifying effects, meaning it can influence cholesterol levels. However, it can also cause a side effect known as flushing, where the skin becomes red and warm. Nicotinamide does not cause this flushing or affect cholesterol in the same way. Because of this, health organizations like the World Health Organization often recommend nicotinamide to treat deficiencies. This allows patients to receive remedial amounts without the discomfort of skin flushing.

History shows how our understanding of these nutrients has evolved. Scientists identified nicotinamide riboside as a form of B3 as recently as 2004. In 1942, the United States government officially adopted the terms "niacin" and "niacinamide." These names were chosen to prevent the public from confusing the vitamins with nicotine, which is toxic. These terms were later included in the United States Adopted Name dictionary in 1961. Today, the term "niacin" is used internationally by groups like the WHO and FDA. It now broadly includes all dietary precursors that can prevent a B3 deficiency.

A severe lack of vitamin B3 leads to a serious disease called pellagra. Pellagra is characterized by several distinct symptoms, including diarrhea and sun-sensitive dermatitis. This skin condition can cause hyperpigmentation and a thickening of the skin. Patients may also experience inflammation of the mouth and tongue, as well as headaches and tiredness. In more advanced stages, pellagra can cause delirium, dementia, and even death if left untreated.

This deficiency is most common in areas where maize, or corn, is a staple food. Because maize is low in digestible niacin, many cultures use a cooking technique called nixtamalization. This process involves treating the maize with alkali ingredients to increase the bioavailability of the vitamin.

Other medical conditions can also impact B3 levels. Hartnup disease is a hereditary disorder where the body fails to absorb the amino acid tryptophan. Because tryptophan is a precursor for niacin, this leads to a deficiency similar to pellagra. Additionally, carcinoid syndrome can cause a deficiency because the body diverts tryptophan to form serotonin instead. To monitor niacin status, scientists do not look at plasma concentrations. Instead, they measure the excretion of a specific metabolite called N1-methyl-nicotinamide in a 24-hour urine collection. For adults, a value below 5.8 μmol/day is considered a deficient status.

Interestingly, the components of vitamin B3 are not unique to Earth. Scientists have detected nicotinic acid and nicotinamide in carbonaceous chondrite meteorites. They have also found these molecules in samples returned from the asteroids 162173 Ryugu and 101955 Bennu. This connection links the fundamental chemistry of human metabolism to the wider composition of our solar system. It shows that the very substances that keep our cells running are also scattered throughout space.