Inositol is a naturally occurring nutrient that is usually classified as a carbocyclic polyol. The most common form of inositol is sometimes referred to as myo-inositol. In the human body, inositol plays a major role in preventing the collection of fats in the liver, as well as promoting healthy hair growth. The presence of the nutrient also aids in efficient processing of nutrients into the conversion of energy, which in turn helps the body to maintain a healthy metabolism. Inositol also can be considered brain food, as the nutrient is necessary to properly nourish the brain.
The sweet nature of inositol comes in part from the properties that make up the nutrient, in particular the component of cyclohexanehexol. While still a form of sugar, inositol works differently from glucose. The main information about inositol in the body has more to do with what happens when there is a deficient amount present. A lack of inositol in the system can lead to such conditions as constipation, high cholesterol, problems with vision and general health of the eyes, and hair loss.
While there is no doubt that inositol is helpful to the normal operations of the human body, studies continue to be conducted to determine if there is any definitive proof that adding more inositol to the diet will reverse any major health issue. Some studies indicate that inositol may impact illnesses like depression and cancer. Some researchers believe that inositol can work in conjunction with other nutrients to provide some recovery from an illness or health condition.

What is Inositol?

Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound with formula C6H12O6 or (-CHOH-)6, a sixfold alcohol (polyol) of cyclohexane. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is cis-1,2,3,5-trans-4,6-cyclohexanehexol, or myo-inositol (former name meso-inositol). Inositol is a carbohydrate, though not a classical sugar. It is almost tasteless, with a small amount of sweetness. Inositol an optically inactive alcohol that is a component of the vitamin B complex

How is it Made?
Myo-Inositol is synthesized from glucose-6-phosphate (G-6-P) in two steps. First, G-6-P is isomerised by ISYNA1 to myo-inositol 1-phosphate, which is then dephosphorylated by IMPase 1 to give free myo-inositol. In humans most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.

Where is it Found?
The most important sources of inositol are liver, brewer's yeast, dried lima beans, beef brain and heart, grapefruit, raisins, wheat germ, unrefined molasses, peanuts, and cabbage.

Benefits / Uses

Dosage
In addition, the small amounts commonly found in multivitamin supplements are probably unnecessary and ineffective. Doctors sometimes suggest 500 mg twice per day. For depression, anxiety, and obsessive-compulsive disorder, 12-18 grams per day has been shown to be effective in double-blind trials. There is no recommended daily allowance for inositol, but the normal human dietary intake is about 1 gram per day. Dosages in the range of 12-18 grams daily have been used for certain conditions such as panic disorder. For the management of depression and panic attacks, 12 grams of myo-inositol daily, in divided doses, were used in clinical studies.

Possible Side-Effects / Precautions / Possible Interactions
To date, there are no reported toxic side effects of inositol. The only known adverse effect of taking large doses of this nutrient is to suffer from diarrhea. Some of the reported problems with inositol include:
Nausea
Fatigue
Headaches
Dizziness.

These are all side-effects that are seen in almost all medications or supplements, probably because such symptoms are common in all people, regardless of whether they are taking medications or supplements.

Reported Side-Effects with Inositol
There are a few less common, but more serious, inositol side effects that you should report to your healthcare provider. These include but are not limited to: Worsening of bipolar disorder (although this was reported in only one case and may have been caused by other factors)

Research Studies / References