Inositol is an important nutrient essentially required for glucose metabolism. It is also associated with improving the symptoms of metabolic diseases, PCOS and infertility.

Characteristics of Inositol

• It is a natural compound, found widely in animal as well as in plant sources. It can also be chemically synthesized in laboratory
• It is basically a carbocyclic sugar that plays significant role in cellular growth
• It also acts as a precursor for surfactant synthesis

Types of Inositol

• Nine types of inositol are found in nature. Among which two types are most important, named D-chiro-inositol and myo-inositol
• They play several important biochemical functions within body. Especially they play important role in preventing the consequences of polycystic ovarian syndrome (PCOS) and metabolic syndrome
• It has seen that the ratio of myo-inositol and D-chiro-inositol in body is about 40:1

Mechanism of action

• Isomers of inositol are mostly present in free form or as a compound of phospholipids or in the form of inositol phosphate derivatives
• It basically acts as second messenger and helps in signal transduction, which is responsible for regulating the activity of hormones within body

Health benefits

 Role on reducing anxiety

• It plays important role in preventing anxiety by balancing various important chemicals within brain that are responsible for influencing mood
• It has seen that inositol plays significant role in improving serotonin activity, which helps to improve the feeling of well being
• It also helps to reduce the prevalence of obsessive compulsive disorder,  post traumatic stress disorder and agoraphobia

Role on preventing depression

• Consumption of inositol is very effective for improving the symptoms of depression
• Depression has a connection with the secretion of neurotransmitter. Imbalance in neurotransmitter secretion develops depression and inositol helps to prevent it by stimulating their release
• It has seen that consumption of inositol along with Vitamin B8 significantly reduces depression
• It also helps to reduce fatigue as well as tension

Role on reducing panic disorder

• Panic disorder is considered as the severe form of anxiety, which is responsible for developing various dangerous consequences within body
• It is mainly characterized by frequent panic attacks, dizziness, shortness of breath, rapid heartbeat, tingling sensation in hand and sweating

• Inositol plays significant role in reducing the number of panic attacks, and helps to improve the overall symptoms

Role on preventing diabetes

• It helps to prevent the susceptibility of developing diabetes mellitus as it plays important role in glucose metabolism
• It has seen that digestion of carbohydrates produce glucose as an end product, which is then absorbed into blood vessels and increases glucose concentration. It triggers insulin secretion from pancreas that helps to transport the glucose from blood to liver. Inositol helps in insulin activity by acting as second messenger for insulin function
• When insulin binds with its receptor then a metabolic event is initiated with the help of phosphatidylinositol-3-phosphate (compound of inositol) that activates protein kinase B, which is responsible for regulating blood sugar level
• Inositol plays another important role in regulating blood sugar concentration by activating the enzyme pyruvate dehydrogenase, which acts on GLUT 4 (glucose transporter 4) that facilitates glucose transportation from blood to cells where it is extensively used as energy substrate
• It also helps to reduce the risk of developing gestational diabetes

Role on preventing PCOS

• Polycystic ovarian syndrome is considered as one of the main cause of female infertility, menstrual irregularities and ovarian dysfunction. It is mainly characterized by elevated level of androgen (a male hormone) and cysts within ovary
• Two main isomers of inositol like myo-inositol (MI) and D-chiro-inositol (DCI) play significant role in reducing the prevalence of PCOS and it helps to improve the pathological conditions related with PCOS
• MI helps in regulating glucose uptake and also regulates the level of FSH in ovaries
• Whereas DCI is responsible for affecting the insulin mediated androgen level within ovary

Role on reproduction

• It helps in reproduction and prevents both male as well as female infertility
• Consumption of inositol is closely related with improving the quality of oocytes
• It also supports the implantation process by improving the quality of embryo
• It has seen that inositol (especially MI) is extensively used for treating women undergoing in vitro fertilization for improving their oocytes quality
• It also helps to treat oligoasthenoteratozoospermia (OAT), a serious complication of male, which is characterized by reduced sperm count with an alteration of sperm morphology and functions
• MI helps to increase the number and activity of sperms, which improves fertility rate

Role on reducing the prevalence of metabolic syndrome

• Inositol has potential role in preventing metabolic syndrome
• It has seen that it helps to reduce the concentration of triglycerides within body that helps to maintain the lipid profile and helps to prevent hyperlipidemia
• It is also useful for preventing obesity
• It also helps to reduce the risk of developing cardiovascular diseases by reducing total fat concentration of body and by preventing hypertension

Other health benefits

• It has seen that consumption of inositol and folic acid during pregnancy reduces the risk of having preterm infants
• Inositol helps to reduce the consequences of acute respiratory distress syndrome (ARDS) and also prevents breathing complications (especially among preterm infant)
• It helps to reduce the prevalence of gout by decreasing uric acid concentration
• It is also useful for treating insomnia

Recommended dietary allowance

• It is better to consume 2 g of inositol (in any form) twice a day for reducing metabolic syndrome (like diabetes, obesity and cardio vascular diseases)
• Individual who have panic disorder should consume 12 to 18 g of inositol per day
• 18 g of inositol should be consumed for preventing obsessive-compulsive disorder
• It is better to consume 1200 mg of inositol (especially DCI) daily for reducing the harmful consequence of polycystic ovary syndrome

Recent findings

• Recent researches have shown that supplementation of inositol (especially MI) helps to reduce the consequences of non alcoholic fatty liver disease, insulin resistance and endoplasmic reticulum stress (Michell R.H, 2018)
• According to current studies it has seen that inositol plays various important roles within body and for improving its function it is better to enhance the biosynthesis of inositol, which can be done by synergestic utilization of glycerol and glucose (Tang et al., 2020)

Deficiency disorders

Below table will show an overview of the causes and consequences of inositol deficiency –

Hyperactivities

• Excessive consumption of inositol is responsible for developing various health hazards like nausea, vomiting, abdominal discomfort, stomach pain, dizziness and headache
• As it reduces blood sugar level, hence individuals who are on hypoglycemic drugs or insulin should monitor their blood sugar concentration while consuming inositol for reducing the risk of hypoglycemia
• It is better to consume inositol as per recommendation for avoiding the risk of its deficiency and toxicity

Chakraborty, A., 2018. The inositol pyrophosphate pathway in health and diseases. Biological Reviews, 93(2), pp.1203-1227.

D'Souza, S.W., Copp, A.J., Greene, N.D. and Glazier, J.D., 2020. Maternal Inositol Status and Neural Tube Defects: A Role for the Human Yolk Sac in Embryonic Inositol Delivery?. Advances in Nutrition.

Genazzani, A.D., 2016. Inositol as putative integrative treatment for PCOS. Reproductive biomedicine online, 33(6), pp.770-780.

Michell, R.H., 2018. Do inositol supplements enhance phosphatidylinositol supply and thus support endoplasmic reticulum function?. British Journal of Nutrition, 120(3), pp.301-316.

Özturan, A., Arslan, S., Kocaadam, B., Elibol, E., İmamoğlu, İ. and Karadağ, M.G., 2019. Effect of inositol and its derivatives on diabetes: a systematic review. Critical reviews in food science and nutrition, 59(7), pp.1124-1136.

Tang, E., Shen, X., Wang, J., Sun, X. and Yuan, Q., 2020. Synergetic utilization of glucose and glycerol for efficient myo‐inositol biosynthesis. Biotechnology and Bioengineering, 117(4), pp.1247-1252.

Zheng, X., Lin, D., Zhang, Y., Lin, Y., Song, J., Li, S. and Sun, Y., 2017. Inositol supplement improves clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. Medicine, 96(49).