Vitamin B3 is a water-soluble vitamin belonging to the vitamin B complex. It contributes to over 200 biochemical reactions in the body, making it a key element of human metabolism.
What is Vitamin B3?
It consists of 2 molecules of nicotinamide and nicotinic acid, often referred to as niacin. In particular, vitamin B3 together with the amino acid tryptophan participates in the formation of two coenzymes of NAD (Nicotinamide adenine dinucleotide) and NADP (Nicotinamide adenine dinucleotide phospate), which are involved in many biochemical reactions.
As a coenzyme, it participates in hundreds of reactions involving food digestion, energy production and even in the antioxidant protection of the body. Niacin takes part in:
- macronutrient metabolism (carbohydrates, proteins, fat)
- energy production
- fatty acid composition
- synthesis of hormones
- production of cholesterol, acetylcholine etc.
Sources of niacin
Niacin exists in great abundance in many foods. Rich sources of vitamin B3 are beer yeast, meat, whole grains, nuts (pistachios and walnuts) as well as some enriched cereal products. Despite its abundance in food, niacin can also be produced by the liver by the amino acid tryptophan, so eggs, dairy and cheese products can indirectly be good sources of niacin too.
Deficiency in niacin and symptoms
Deficiency of vitamin B3 is not common. However, corn-based nutrition or reduced tryptophan intake, and hence a reduced synthesis of niacin hepatically, results in a condition called Pellagra. People who suffer from alcoholism or chronic malabsorption can lead to a lack of niacin.
Symptoms of niacin deficiency are:
- Dermatological problems (glossitis, dermatitis, dry mouth)
- Neurological disorders
- Changes mood and feeling of fatigue
- Gastrointestinal problems (eg diarrhea)
- Arrhythmia and hypotension
What is niacin flush?
Supplemental administration of niacin can lead to a feeling of blush and redness on the face. It is caused due to niacin (nicotinic acid) intake. It is not dangerous to health and it is a temporary phenomenon. Dietary supplements containing nicotinamide as a form B3, do not have the above effect. Usually, on the nutritional label, there is a reference whether the preparation causes niacin flush or not.
Niacin actions and benefits
Studies in humans have shown that administration of niacin supplements can reduce the risk of stroke in people who don’t take statins. It also appears to have a protective effect against atherosclerotic plaque formation by reducing inflammation and endothelial vessel destruction. Additionally, niacin supplements can reduce blood pressure in people with hypertension or dyslipidemia.
Niacin appears to be involved in the anti-inflammatory mechanisms of the body. In particular, butyric acid produced by colonic bacteria acts on the niacin receptor and exerts topical anti-inflammatory effects. Niacin receptor in the intestine plays an important role in the communication between intestinal microflora and immune system.
Cholesterol and triglycerides
Supplements of nicotinamide have been shown to effectively reduce blood lipids, as they reduce the production of triglycerides and lipoproteins in the liver. In particular, it was observed that after supplementary administration of niacin, there was an increase in HDL cholesterol levels and a decrease in LDL, vLDL cholesterol levels. Correspondingly to cholesterol levels, pharmacological doses of niacin help reduce serum triglycerides in subjects with hypertriglyceridemia about 30-50%.
Nervous system and energy
Due to the fact that niacin participates in the mechanisms of digestion and metabolism of foods, supplementation of niacin reduces fatigue and boost body with energy. It also helps reduce anxiety and nervousness, contributing to the good functioning of the nervous system.
How much niacin do we need?
The recommended daily dose is 14mg for women and 16mg for men. A typical dose of supplements is 15-30mg, but in pathological conditions, the dosage can be increased significantly from 100-500mg daily. High doses should be equally distributed throughout a day. The absorption and action of niacin are better when taken with a meal, along with vitamins of B complex. Food supplements marked as “no flush“, do not cause redness.
Niacin side effects and contraindications
Prolonged intake and high doses of niacin may result in insulin resistance and elevated serum glucose levels. Large doses of niacin can lead to liver damage, myopathy, gout and dry skin.
Alcoholics, as well as people with diabetes, gout, stomach ulcer and liver diseases, should not take niacin supplements. Taking vitamin B3 during pregnancy and breastfeeding is safe with medical supervision.