Vitamin B7
Inositol is a non-essential substance for the organism, which is able to produce it autonomously alongside that of food origin. It is currently considered a vitamin-like nutrient, since there are no certainties on the essentiality of the exogenous supply (which is ensured by the wide food distribution). In spite of this consideration, some authors report it with the acronym vitamin B7.
Inositol can be found in different isomeric forms, among which myo-inositol stands out due to its first-rate biological role.
Inositol in food and functions in the body
The most generous food sources are represented by bran, whole grains, wheat germ, brewer's yeast, citrus fruits, meats in general and in particular the liver. The latter represents the key organ for its endogenous synthesis (an action shared with the kidney). Inositol, which has a molecular formula identical to that of glucose, but with a different structure, is synthesized from glucose 6-phosphate (the first product of glycolysis); the excess is catabolized and eliminated in the kidney. Similarly to the B vitamins, inositol is water-soluble, which is why any supplementation is well tolerated and free from toxicity.
Once produced, "inositol enters the cells, where" it is largely transformed into phosphatidylinositol; the biological actions of this substance are many and in some ways still to be clarified. We know, for example, that it is active in plasma membranes, where it participates, as a precursor of second messengers, in the signal transmission systems that control cellular activity.
Inositol, which stimulates the production of lecithin (phosphatidylcholine) in the body, is advertised for its supposed ability to reduce the level of cholesterol in the blood. The action of lecithin, in fact, is good-naturedly comparable to that of a broom, which cleans the walls of the arteries of lipid deposits and carries them to the liver (where they are partly eliminated through the bile). Similarly, inositol prevents that this organ accumulates too many lipids and "fattens" (hepato-protective action against steatosis).
Inositol also helps the brain in states of anxiety, depression and severe mental stress (it is considered a mild sedative).
Since mice deprived of their food supply lose their hair, inositol is advertised as an effective remedy in the treatment of alopecia (it is a pity, or fortunately, that humans do not move on all fours and do not have equally developed incisors! ).
Inositol supplements
The optimal intake dose has not yet been fixed; for this reason the recommended dosages vary from one up to 12 or more grams per day (at high doses it can have a laxative effect).
Recalling that inositol is widely spread in foods and is synthesized by the body, the usefulness of its integration is doubtful, above all because there are, for each field of action, more studied and proven alternatives (soy lecithin or fermented red rice, for example, to lower cholesterol, milk thistle for the hepatoprotective effect and St. John's wort for the treatment of depressive states and anxiety).
Since some of these supplements can alter the activity of certain drugs and should not be used by some individuals, before purchasing and taking particular supplements, including inositol, it is advisable to rely on the advice of experienced and qualified people.
