Inositol, an 'unofficial' B-vitamin, is a cyclic 6-carbon compound quite similar to glucose. In animal cells, it occurs as a component of phospholipids and it stored predominantly in the brain, spinal cord nerves, cerebral spinal fluid, skeletal muscle, and heart muscle. The human body contains more inositol than any other vitamin except niacin.
Inositol appears to be a precursor of the phosphoinosities (compounds that may be important in hormonal action) especially in the brain. Proper action of several brain neurotransmitters, such as acetylcholine and serotonin, require inositol.
Inositol encourages hair growth and can help prevent baldness. Like choline, inositol helps to move fat out of the liver, and helps prevent serious liver disorders, as well as disorders involving high cholesterol.
Serotonin and acetylcholine, two neurotransmitters, both depend upon inositol, and supplementation can therefore assist in the reduction of depression and panic attacks. A reduction in brain inositol levels may induce depression as evidenced by low inositol levels in the cerebrospinal fluid of patients with depression. In a 1-month, double-blind, placebo-controlled study of 28 patients with depression, inositol demonstrated therapeutic results similar to tricyclic antidepressants without the side-effects. Additional studies have revealed that inositol supplementation is an effective treatment in panic and obsessive compulsive disorders.
Loss of inositol from nerve cells is the primary reason for diabetic neuropathy, so inositol supplementation can assist in improving this condition. Phytic acid, the plant source of inositol, has been shown to have anticancer properties, which may be one reason why a high-fiber diet protects against many cancers.
Inositol also has a prominent calming effect on the central nervous system, so it may be helpful to those with insomnia. Studies on brain waves have shown that it has an effect similar to that of librium or valium. It can gradually lower blood pressure, and can be helpful in cases of schizophrenia, hypoglycemia, and those with high serum copper and low serum zinc levels.
Intake of caffeine is known to deplete the bodies supply of inositol.
It is best used with choline, which should be taken in the same amount as inositol. It is best to take the entire B-group vitamins with it. Vitamin E, vitamin C as well as folic acid and linoleic acid are thought to increase the functioning of inositol.
One study showed that 18gm of inositol daily (2 tsp in juice 3 times daily) for 6 weeks significantly reduced OCD symptoms compared with placebo. At 3 weeks there were no significant effects of inositol. The mechanism may be that the desensitization of serotonin receptors is reversed by addition of dietary inositol. [Brain Res 631: pp.349- 51, 1993; American Journal of Psychiatry, September, 1996;153(9): pp.1219-1221]
Inositol has been found to be effective in treating panic disorder. Inositol works by regulating the action of serotonin, a calming neurotransmitter, within the nerve cells. Its safety has been noted up to 20gm per day.