Vitamin B3

Vitamin B3

DEFINITION
Niacin (Nicotinic acid or Nicotinamide) is an essential
dietary vitamin that belongs to the B group vitamins.
DESCRIPTION
Vitamin B3 is essential for the activity of many enzymes in
the body. Enzymes are special substances that speed up chemical
reactions in the body. These enzymes are responsible for the
production of energy in the body, the breakdown of dietary fats,
the production of certain hormones and cholesterol, the processing
of genetic material (DNA) and the growth and maturation of the
cells in the body. Vitamin B3 is absorbed rapidly from the gut,
transported to all the body tissues and any excess is excreted in
the urine. Large doses of Vitamin B3 can cause flushing of the skin
and liver abnormalities, although both of these problems disappear
when the vitamin is broken down and excreted by the body.
MEDICAL USE
Always consult your Doctor for advice on dosages and drug
interactions before taking any dietary supplements. 
  • The Nicotinic Acid form of Vitamin B3 is used medically to
    treat and prevent Vitamin B3 deficiency (pellagra) and to lower the
    blood cholesterol levels of patients with high cholesterol
    levels. 
  • Nicotinamide may also be given to people with certain types of
    cancer, such as bladder cancer, prior to radiotherapy, as it can
    make cancer cells more sensitive to this treatment. 
  • There is some evidence to suggest that a high intake of Niacin,
    particularly from food sources, may help to reduce the risk of
    Alzheimer’s disease.
DEFICIENCY
A deficiency of Vitamin B3 causes a condition called pellagra.
Pellagra is most often seen in chronic alcoholism, malnutrition and
people with multiple vitamin deficiencies. Pellagra causes
dermatitis, diarrhoea and dementia. There is also a bright red rash
resembling sunburn, irritation of the mouth, inflammation and
ulceration of the tongue, nausea and vomiting, insomnia,
depression, headache dizziness, delusions, hallucinations and
anaemia.
SOURCES
Good food sources of Vitamin B3 include yeast (e.g. Brewer’s
yeast), meat (particularly liver), fish, poultry, dairy products,
eggs, cereals such as rolled oats porridge, rice or wheat with
lesser amounts in corn, legumes (beans and peas), seeds and leafy
green vegetables.
DOSAGE
The recommended dietary intake (RDI) of Vitamin B3 is 19 mg
per day for adult males and 13 mg per day for adult females,
although females who are pregnant require 15 mg per day and those
that are lactating require 18mg per day. Much larger doses of
Vitamin B3 may be given for specific medical conditions under the
supervision of a qualified health care professional.