Vitamin B3: NIACIN

Vitamin B3, most commonly known as niacin, but also known as nicotinic acid and vitamin PP, is an essential human nutrient. Vitamin B3 is a water soluble, solid vitamin that comes in other forms such as amide and nicotinamide, both of which contain the same biochemical activity. The terms are often used interchangeably. However, it should be noted that nicotinamide does not have the same pharmacological effects as niacin. Nicotinamide does not reduce cholesterol or cause flushing and may be toxic at doses higher than 3g/day.

Vitamin B3: Functions in the Human Body

Vitamin B3 (niacin) is involved in DNA repair and the production of steroid hormones in the adrenal gland. Vitamin B3 is important for maintaining healthy skin and normal nerve and brain functions. It also plays an important part in memory improvement, digestion and the absorption of proteins, fats, and carbohydrates. Niacin is capable of reversing atherosclerosis by reducing total cholesterol, triglycerides, very-low-densitylipoprotein (VLDL), and low-density lipoprotein (LDL), and increasing high-density lipoprotein (HDL). By increasing high-density lipoprotein, niacin can reduce the risk of heart attack.

Vitamin B3: Recommended Daily Intake

The recommended daily intake (RDI) for vitamin B3 is as follows:

• 16 mg/day for men
• 14 mg/day for women
• 18 mg/day for pregnant or breast-feeding women
• 2–12 mg/day for children
• The Tolerable Upper Limit (UL) for adult men and women is 35 mg/day

Vitamin B3 deficiency is rare in developed countries and usually occurs where poverty and malnutrition is prevalent. Chronic alcoholism is also known to cause deficiency. Severe deficiency causes pellagra, a disease causing symptoms of dermatitis, diarrhea, dementia, lesions on the lower neck, thickening of the skin, hyperpigmentation, digestive problems, amnesia, delirium, inflammation of the mouth, and potentially death. More common psychiatric symptoms of niacin deficiency are anxiety, fatigue, irritability, poor concentration, apathy, depression, and restlessness.

Vitamin B3: Risk of Overdose

At high doses niacin can have life-threatening results. Research has shown that doses higher that 1.5-6g per day may lead to dermatological conditions such as flushing and itching, skin rashes, and dry skin. Niacin administered at doses for lowering cholesterol has cause birth defect in laboratory animals and, as such, may cause birth complications in pregnant women. Other health problems related with niacin overdose are gastrointestinal problems such as nausea, indigestion, and liver toxicity.


Source: WL