Inositol is a water-soluble member of the B complex group of vitamins. It is not a true vitamin because it is made in small quantities within the body. Inositol is also known as:

  • bios 1
  • myo-inositol
  • meso-inositol
  • lipotropic factor

It is regarded as a fat-fighter along with choline with which it is closely associated.

Inositol is a coloured crystalline substance and a major constituent of lecithin. It is active in metabolising fats and is thought to assist in lowering levels of cholesterol.

Inositol is measured in milligrams (mg)

Inositol is widely distributed in plants and animals in varying quantities. It is found in all foods that contain choline.

Cereals and vegetables contain inositol in a derivative form known as phytic acid and not in a free form. Phytic acid is a combination of inositol and phosphorus and has properties that differ greatly from those of inositol. It is known to reduce absorption of the minerals zinc, iron and calcium, whereas free form inositol has the reverse effect, actually increasing the body’s utilisation of these elements.

Some of the phytic acid in fruit and vegetables is eventually degraded into inositol but the extent of this action is unknown. As the amount provided in this way can neither be measured nor assessed, it is not regarded as relevant.

A good diet provides an ample supply of inositol, with the result that deficiency in this vitamin seldom occurs. Body cells and bacteria in the intestine also produce inositol, synthesising it from glucose.

What does inositol do in the body?

Like choline, inositol is important as a lipotropic agent, keeping body fats emulsified and preventing a build-up of fatty deposits in the wrong places, i.e. the organs and arteries.

Although inositol and choline have similar functions, their chemical structures are different. The fat fighting properties of inositol appear to enhance those associated with choline. It is not therefore surprising that in nature they regularly occur in the same foods, enabling each to complement the action of the other.

Being a water-soluble substance, inositol is not stored but used continually in the body cells. It needs interaction with other B vitamins to be fully utilised. Inositol is excreted in the faeces and urine, probably at the same rate as choline, i.e. approximately 5 – 9 mg a day depending on the diet.

Like other nutrients in the B complex family and in particular, choline, the activity of inositol will be impaired by alcohol, food processing and the contraceptive pill.

Foods containing inositol are subject to loss of the vitamin because of its solubility. Cooking with frozen meat or offal can also reduce levels of the nutrient, which is lost in water as the food thaws. 

Excessive intake of coffee is not recommended because the caffeine, being a stimulant, reverses the calming effect that inositol appears to exert.

There are no specific deficiency symptoms associated with inositol. Deficiency is rare since it can be obtained from such a wide selection of foods and is produced in more than adequate amounts within the body.

Choline and inositol work naturally together. They also occur in the same foods and appear to be compatible in terms of health. Other B complex vitamins also appear to increase the efficiency of this lipotropic nutrient.

Sign up to our newsletter