Vitamin B3

Vitamin B3, more commonly known as niacin, is another water soluble vitamin member of the B complex group. It is also known as nicotinic acid and vitamin PP (pellagra-preventative).

Nicotinic acid was first described in 1867 but was not recognized as a vitamin till 1937 by the work of the American Dr Conrad Elvehjem.

B3 is found in many foods but is also naturally produced by the body using an amino acid (tryptophan) found in protein.

• It helps with the normal functioning of the brain, nervous system and digestive system.
• It also helps maintain a healthy skin.
• It aids the metabolism of carbohydrates, fats and protein.

Important

• Liver (100g serving)
• Meat (100g serving)
• Fish (fresh and tinned) (100g serving)
• Peanuts (50g serving)
• Yeast products e.g. Vegemite/Marmite (3g serving)
• Fortified breakfast cereals (30g serving)

Moderate

• Nuts (50g serving)
• Percolated coffee (250ml serving)
• Avocado pear (150 g)
• Potatoes (120g serving)

Low or Nil

• Fruit, vegetables, eggs, dairy products, pulses
• Fats and oils (trace)

Note: More than half of the average person's niacin requirements is actually produced in the body from dietary protein.

B3 is normally reasonably stable though it can be lost into cooking water since it is water soluble. It is also lost in drips from thawing frozen foods.

Only a comparatively small percentage is eliminated in responsible commercial food processing.

Excessive alcohol consumption is a natural enemy because it impairs the vitamin's absorption and utilization in the body.

Severe deficiency results in a disease called pellagra.

This disease became quite common among peasants in Spain and Italy when corn was introduced in the early eighteenth century. Corn quickly became an important part of the peasant's diet but because the grain has a very low content of the amino acid tryptophan as well as a low niacin content the diet was extremely deficient in vitamin B3.

The severe deficiency symptoms of pellagra are the "three Ds" - dermatitis, diarrhea and dementia. Less advanced symptoms include general fatigue and weakness, loss of appetite and skin disorders. Of course, these early symptoms could apply to numerous - other diseases or illnesses.

Today pellagra is largely confined to poverty stricken countries where corn is the staple diet.

The food source requirement of B3 is influenced by the amount of B3 produced naturally by the body.

Therefore an intake formula has been worked out to include both the two natural sources (i.e. derived from food and manufactured by the body). The recommended daily intake is then expressed in "niacin equivalents" .

The amount of niacin required also bears a relationship to the number of kilojoules consumed.

The Australian recommendation is 18 milligrams for a healthy male adult (decreasing slightly as he becomes older) and 13 milligrams for a woman (decreasing slightly with age but increasing during pregnancy and while breast feeding). The increase required by women is usually taken care of by the body's natural manufacturing process which works overtime during pregnancy and lactation.

A high supplementary dosage is sometimes used to lower cholesterol levels when treating a heart condition. Such a dosage must only be taken under strict medical supervision.

There have been widespread claims that B3 is a "miracle drug" for the treatment of schizophrenia.

However, there is absolutely no reliable supporting scientific evidence so the claims must be written off as myths or wishful thinking.

Normally B3 is considered non toxic. However, large doses (more than 3 grams per day) can cause irritability and hot flushing sensations.