Vitamin B3 (Niacin)

Vitamin B3 (Niacin)

Overview:

Vitamin B3, also known as niacin, is a water-soluble vitamin essential for metabolic processes. It exists in two forms: nicotinic acid and nicotinamide, both of which are precursors to coenzymes NAD and NADP.

Sources:

Niacin is found in foods such as meat, fish, poultry, enriched and whole grain breads, fortified cereals, and certain vegetables like potatoes.

Functions:

Energy Metabolism: Niacin is vital for the conversion of food into energy. NAD and NADP, its coenzyme forms, are crucial in metabolic pathways.

DNA Repair and Stress Responses: Niacin helps in DNA repair and the synthesis of steroid hormones in the adrenal gland.

Deficiency:

A severe niacin deficiency leads to pellagra, characterized by the four Ds: dermatitis, diarrhea, dementia, and if untreated, death. Early symptoms include fatigue, depression, and mouth sores.

Toxicity:

Excessive intake of niacin can cause side effects like skin flushing, itching, gastrointestinal disturbances, and liver toxicity, especially when taken in supplement form at high doses.