Niacin, also known as vitamin B3 , is a water-soluble vitamin that's essential for energy metabolism, cellular function, and skin health. It's a B vitamin and plays an important role in converting food into energy. Niacin is often used to support cholesterol levels and heart health. In this article, you'll learn about the benefits of niacin, how it works in the body, and how to use it safely.
What is niacin (vitamin B3)?
Niacin is a water-soluble B vitamin that exists in two forms: nicotinic acid and nicotinamide (niacinamide) . Both forms are biologically active in the body and perform similar functions. Niacin is converted in the body to the coenzyme nicotinamide adenine dinucleotide (NAD) , which is involved in hundreds of reactions, including energy production, DNA repair, and cell communication. Vitamin B3 is also essential for maintaining healthy skin and nervous system function [1].
Synonyms for Niacin
Niacin is also known as nicotinic acid and niacinamide . One of the two forms is often used in dietary supplements, with nicotinic acid often used to support cholesterol levels, while niacinamide is used in skincare products to promote skin health [2].
Where does niacin come from?
Niacin occurs naturally in many animal and plant foods. Good sources include meat, fish, poultry, eggs, dairy products, whole grains, and nuts. Niacin can also be synthesized by the body from the amino acid tryptophan when sufficient protein is available in the diet. Niacin is also added to fortified foods such as bread and breakfast cereals to meet daily requirements [3].
How is niacin produced?
Niacin can be obtained naturally from foods or synthetically. Niacin is available in dietary supplements in the form of nicotinic acid or niacinamide. These two forms are chemically stable and easily absorbed by the body. Niacinamide is commonly used in skin care products, while nicotinic acid is often used in higher doses to lower cholesterol [4].
Health benefits of niacin
Niacin and energy metabolism
One of niacin's most important functions is its role in energy metabolism. It helps the body convert carbohydrates, fats, and proteins into usable energy by acting as a coenzyme for many enzymes involved in metabolic processes. Without sufficient niacin, the body would not be able to produce energy effectively, which can lead to fatigue and general weakness. Niacin also supports the function of mitochondria, the "powerhouses" of cells, thus contributing to energy production [5].
Niacin and skin health
Niacin, especially in the form of niacinamide, is commonly used in skin care products because it strengthens the skin barrier, retains moisture, and reduces inflammation. It can help reduce skin redness, acne, and hyperpigmentation. Additionally, niacin promotes the production of ceramides, which are crucial for maintaining skin hydration. Niacinamide is also known to reduce the signs of aging and improve skin texture [6].
Niacin and heart health
Nicotinic acid, a form of niacin, is known to lower cholesterol levels. It can lower LDL ("bad") cholesterol and triglycerides while increasing HDL ("good") cholesterol. These properties make niacin a valuable supplement for people at increased risk of cardiovascular disease. However, it is important to take nicotinic acid only under medical supervision, as high doses can cause side effects [7].
Knowing how to properly support your heart is super important – for now and for later.
If you want to learn what vitamin K has to do with it, check out this article: Vitamin K – important for blood, heart & health .
Niacin and the nervous system
Niacin plays an important role in the functioning of the nervous system by supporting communication between nerve cells. A deficiency in niacin can lead to neurological symptoms such as fatigue, irritability, difficulty concentrating, or even a condition called pellagra , which is associated with symptoms such as dermatitis, diarrhea, and dementia. Adequate niacin intake is therefore crucial for maintaining mental and emotional health [8].
Niacin and detoxification
Niacin supports detoxification in the body, particularly in the liver. It plays a role in the cytochrome P450 system , an enzyme system responsible for breaking down toxins and medications in the liver. As a result, niacin helps the body break down and eliminate harmful substances. It is also sometimes used in detox protocols to assist the body in eliminating environmental toxins [9].
Niacin and cognitive function
Recent studies suggest that niacin may also play a role in maintaining cognitive function. Vitamin B3 deficiency has been linked to an increased risk of neurodegenerative diseases such as Alzheimer's disease. Niacin supports brain cell health and may help improve cognitive function and memory, especially in old age [10].
How does niacin work in the body?
Niacin acts as a coenzyme in various metabolic processes in the body, particularly energy metabolism. It is converted into NAD (nicotinamide adenine dinucleotide) and NADP (nicotinamide adenine dinucleotide phosphate), which are involved in the conversion of nutrients into energy. Niacin also supports the function of the nervous system by promoting signal transmission between nerve cells. Furthermore, it helps in the repair of DNA damage and the regeneration of skin cells [11].
Recommended dosage and use of niacin
What is the recommended dosage of niacin?
The recommended daily intake (RDA) of niacin is approximately 16 mg per day for adult men and approximately 14 mg per day for women. Pregnant and breastfeeding women have slightly higher needs. Higher doses of nicotinic acid or niacinamide may be recommended for the treatment of certain conditions, such as high cholesterol or skin problems, but this should only be done under medical supervision to avoid side effects [12].
When should you take niacin?
Niacin can be taken at any time of day, preferably with food to avoid stomach upset. When taking higher doses of nicotinic acid to lower cholesterol, it is often recommended to take the supplement with a meal and plenty of water to minimize potential side effects such as flushing [13].
Side effects and safety of niacin
Is niacin safe?
Niacin is safe and well-tolerated at recommended doses. However, taking high doses of nicotinic acid to lower cholesterol can cause side effects, including skin reddening, itching, stomach upset, and headaches. These reactions, known as niacin flush , are usually harmless but unpleasant. In extremely high doses, niacin can impair liver function, so it should be taken under medical supervision [14].
What are the side effects of niacin?
The most common side effect of high doses of nicotinic acid is niacin flush, a temporary reddening of the skin accompanied by a tingling or flushing sensation. Other side effects of high doses can include stomach upset, nausea, headaches, and, in rare cases, liver problems. Niacinamide, another form of vitamin B3, generally does not cause flushing and is better tolerated, but the recommended dosage should still be observed [15].
Niacin compared to other B vitamins
Niacin vs. Vitamin B6
Both niacin (vitamin B3) and vitamin B6 are water-soluble B vitamins that play an important role in energy metabolism and cellular function. While niacin is responsible for converting nutrients into energy and DNA repair, vitamin B6 supports protein metabolism and neurotransmitter production. Both vitamins are important for the nervous system and complement each other in their functions [16].
Niacin vs. Folic Acid
Niacin and folic acid (vitamin B9) are both essential B vitamins involved in cellular function and DNA synthesis. While niacin is primarily known for energy metabolism and skin health, folic acid is particularly important for cell division and nervous system development, especially during pregnancy. Both vitamins are essential for overall health and are often combined in multivitamin supplements [17].
Natural sources of niacin
Niacin is found in many foods, including meat, fish, poultry, whole grains, nuts, and legumes. Chicken breast, tuna, salmon, peanuts, and brown rice are particularly rich in niacin. Fortified foods such as breakfast cereals often contain additional amounts of niacin to meet daily needs. A balanced diet is important to ensure adequate niacin intake [18].
Niacin in dietary supplements
Niacin is available in several forms in dietary supplements, including nicotinic acid and niacinamide. Nicotinic acid is often used in higher doses to lower cholesterol, while niacinamide is used in skincare products to improve skin health. Niacin supplements are a good option for people who struggle to get enough of their niacin from their diet, but should be taken cautiously to avoid side effects [19].
Final Thoughts on Niacin
Niacin (vitamin B3) is an essential vitamin that is vital for energy metabolism, skin health, nervous system health, and heart health. It supports the conversion of food into energy, aids in cell repair, and may help regulate cholesterol levels. For people looking to improve their skin, support their nervous system, or lower their cholesterol levels, niacin can be a valuable supplement, either through food or supplements.