Niacin, scientifically known as pyridine-3-carboxylic acid, is a water-soluble B-vitamin (Vitamin B3) essential for human health. It serves as a precursor to the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP), which are vital for energy metabolism, DNA repair, and cellular signaling. Niacin helps convert food into energy, supports the nervous system, and maintains healthy skin. Deficiency leads to pellagra, characterized by symptoms like dermatitis, diarrhea, and dementia. It is naturally present in foods such as meat, fish, poultry, enriched breads, and cereals. In supplements and fortified products, niacin is used to prevent deficiencies and manage conditions like hyperlipidemia, though high doses can cause flushing and gastrointestinal issues. Chemically, it is a stable, white crystalline powder with a slightly bitter taste. Niacin is recognized as generally safe for consumption, with regulatory approval from bodies like the FDA under GRAS status for food additives. Research from peer-reviewed sources, such as the Journal of Nutrition and PubChem, highlights its role in metabolic pathways and potential therapeutic benefits, but emphasizes monitoring intake to avoid adverse effects. Its polarity contributes to high solubility in water and alcohol, making it suitable for aqueous formulations, while its low fat solubility limits its use in lipid-based products.