Niacin is vitamin in the B-complex group. it also called as Vitamin B3 or vitamin PP. It occurs as nicotinic acid and nicotinamide, which have identical biological action. It is a heat-stable vitamin and dissolves in water.

Vitamin B3 supports the emission of energy, fatty acid and cholesterol creation, DNA restoration, and the response to stress. Nicotinamide is the drug of choice for therapeutic usage since it has no adverse effects and is very soluble in water.

Nicotinamide and nicotinic acid can withstand a broad range of conditions, including heat, light, air, and alkali. Cooking and conserving meals result in the lowest losses. The human body obtains niacin either through diet or synthesis through tryptophan, which is an essential amino acid .A diversified and balanced diet provides adequate quantities of niacin.

Functions of Niacin

Encourage the energy yield of the micronutrients

The coenzymes NAD and NADP are necessary for about 200 redox reactions. specially ,NAD plays a key role in generating energy in tissues by metabolizing carbohydrates, fats, and proteins.

Creation of a biological substance

It is essential for the lipid and protein production circuits. Furthermore, tryptophan and niacin combine to produce serotine, a neurotransmitter associated to mood and gastrointestinal motility.

Coordination of the immunological reaction

Niacin controls neuron transcription and signaling between cells. Additionally, it lessens neurogenerative diseases. This vitamin  is closely related to riboflavin and thiamine in the energy-producing cell metabolic system.

DNA Replication

NAD is a source of ADP-ribose, which is transported to proteins by several enzymes. These enzymes and their products appear to play roles in DNA replication, repair, cell differentiation, and signal transduction.

Prevent Diabetes

Type 1 diabetes is caused by an autoimmune attack on insulin-secreting β-cells in the pancreas. Nicotinamide has been proven to postpone or prevent the onset of diabetes.

 To Prevent Cancer

A case-control research indicated that consuming more niacin and antioxidants reduced the risk of mouth, throat, and esophageal cancers.

Food sources of Niacin

Nicotinamide and nicotinic acid are extensively distributed in nature. Plants have a higher concentration of nicotinic acid, whereas mammals have higher levels of nicotinamide .Foods containing high levels of niacin include  liver, chicken, lean meats, nuts, and legumes. Milk and green leafy vegetables have a lower concentration.

Niacin-rich foods are often rich sources of protein. One very rich source of niacin is brewer’s yeast. It is sometimes added to recipes to raise the diet’s niacin level.

In regular meals, tryptophan can supply up to two-thirds of the niacin activity needed by people. Meat, milk, and eggs are excellent sources of tryptophan.

To meet daily requirements, in certain countries, flour is mandated to be fortified to compensate for processing losses of niacin.

Recommended Dietary allowance

Niacin needs are correlated with total caloric intake since It is needed for the utilization of carbs. Depending on an individual’s age and work, the total niacin equivalent needed daily based on calorie requirement may vary from 8 mg to 26 mg.

The table below gives basic information of the daily requirements based on age:

Deficiency of Niacin

Niacin deficiency can cause pellagra, a condition with symptoms including dermatitis, diarrhea, and dementia. A pigmented rash appears symmetrically on skin exposed to sunshine. Neurological symptoms of pellagra include headaches, weariness, sadness, apathy, and memory loss.

Pellagra does not happen often in industrialized countries, but it is more common in people who frequently eat maize and sorghum. are staple crops. It mainly  found in India, portions of China, and Africa. Niacin can be used to relieve the symptoms of this condition. If not treated, pellagra can be fatal.

Oedema, skin rashes, hair loss, and irritability are further signs of deficiency. It is also evident that the patients have certain mental and physiological issues. Niacin deficiency many times lead to fatigue, headache and memory loss, vomiting, dizziness, visionary problem can be occur.

Long-term usage of isoniazid for TB therapy may result in niacin insufficiency due to its niacin antagonist properties. Certain medicines, such as diazepam and phenytoin, might cause niacin deficit by interfering with its metabolism.

Individuals with Hartnup illness, Carcinoid Syndrome, and long-term alcohol and drug use are more likely to experience niacin insufficiency.

Side Effects of Niacin

There is no evidence that niacin from natural foods has negative consequences. Excessive nicotinic acid intake in supplement form more than 300mg per day  can cause negative effects such as nausea, diarrhea, and skin flushing.

Excessive consumption of 2.5 g per day has been linked to hepatotoxicity, glucose intolerance, hyperglycemia, raised blood uric acid levels, heartburn, nausea, and migraines.

Even modest amounts of 750 mg per day can cause severe jaundice and irreparable liver damage. Doses of 1.5-5 g/day of nicotinic acid have been linked to impaired vision and other eye issues.