Inositol
What is Inositol?
Inositol is sometimes referred to as vitamin B8 and it is important for the integrity of cell membranes, mental health and blood sugar regulation.
Inositol is a different form of the sugar molecule, glucose. It is actually a natural sugar alcohol and provides the body with quick energy.
It is sometimes referred to as vitamin B8, Myo-inositol, or d-chiro-inositol. It is considered a micronutrient, but a non-essential vitamin, because deficiency does not translate into disease.[1]
Myo-inositol is the most abundant, stable, and active form in the body. [8]
Inositol is an important part of cell membranes, which are the “walls” surrounding the cells in our body.
Inositol is most often associated with mental health because it is abundant in the brain and because it assists with chemical signaling. It has also been used to help treat a variety of conditions including PCOS, infertility in men and women, regulating blood sugar and cholesterol levels, as well as increasing GABA in the brain which often results in reduced anxiety, obsessive-compulsive disorder, and panic attacks. [1]
There is some evidence to suggest that myo-inositol levels in the brain may be associated with sleep disturbances. [11]
Food Sources of Inositol
Source: Autism Dietitian Instagram
Recommended Intake
These recommendations are based on the Recommended Dietary Allowance (RDA), which is the average daily level of intake sufficient to meet the nutrient recommendations of nearly all (97-98%) of healthy individuals.
There is no RDA for inositol because our bodies can actually make up to 4g per day, primarily in the kidney and brain. [1,7,8]
Deficiency
There are no distinct signs of inositol deficiency.
Inositol deficiency can be the result of a deficiency in the diet, lack of uptake by the cells, or a lack of synthesis within the body. [2]
Low levels of inositol are associated with mental health diseases like depression and schizophrenia spectrum disorder.[4]
Low levels of inositol are also associated with insulin resistance. [5] Supplementation of inositol improves glucose tissue uptake. [1]
High blood sugar induces myo-inositol depletion in nervous system tissues. Myo-inositol depletion, in turn, may worsen insulin resistance and diabetes complications. [6]
Major mood-stabilizing medications like lithium, carbamazepine, and valproic acid can deplete inositol levels. [4]
Dietary supplementation of inositol can restore peripheral levels of myo-inositol in patients taking lithium, valproic acid or carbamazepine, avoiding interference with their central therapeutic effect. Inositol supplementation ameliorated lithium-induced polyuria-polydipsia as well as psoriasis aggravated by the medication. [10]
Excessive coffee intake or long-term use of antibiotics can also deplete inositol levels. [6]
Gut dysbiosis and inflammation may affect the absorption of inositol in the small intestine. Supplementation and the use of prebiotics can improve intestinal function, restore beneficial microbiota and reduce inflammation. [10] This is especially relevant for those with autism because dysbiosis and gut inflammation is so prevalent, inositol absorption may be affected.
Toxicity
There is no defined level of inositol toxicity.
Inositol is absorbed in the small intestine and excess is excreted in the urine. [1]
Consumption of high doses (>12g/day) is reported to cause gastrointestinal issues. [1,7]
Supplements
Inositol supplements are available in powder and capsule forms. Supplements usually contain no more than 4 g/day of inositol, though with depressive disorders doses up to 12–18 g/day (in adults) have been used, without significant adverse events, while showing additional clinical benefits. [10]
Inositol may be poorly absorbed, due to competition with glucose, because the two share transport systems. Cellular inositol uptake is also decreased in the presence of high or even normal glucose concentrations. [6] In such cases, supplementary inositol should be taken far from meals.
Examples
Powder
Capsules
Note: All supplements are linked to Amazon for convenience, however, buying supplements on Amazon does not guarantee quality, as there are many “unverified resellers” selling nutrition supplements. To buy supplements that are verified to be sent directly to the consumer, you can create an account on the Autism Dietitian FullScript and search for the respective supplement under “Catalog”.
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
Inositol & Autism in the Research
Inositol & Disease
A diet low in fiber is also low in inositol which may be related to diabetes, cancer, metabolic syndrome and PCOS. [6]
Several studies elucidated the positive effects of myo-inositol dietary supplementation in various diseases associated with its depletion, including insulin resistance, PCOS, diabetes, gestational diabetes, depression, and metabolic syndrome. [10]
In patients affected by diabetes and insulin resistance, a dietary supplementation of myo-inositol is able to ameliorate glucose metabolism by reducing postprandial glucose levels and increasing peripheral insulin sensitivity. [10]
Inositol & Respiratory Distress Syndrome
Inositol supplementation (equaling the amount in breast milk) during the early neonatal period decreases the likelihood of severe, chronic injury of the retina and the lung in premature infants with respiratory distress syndrome. [2]
Inositol & Mental Health
Adolescents with elevated traffic related air pollution (TRAP) exposures demonstrate altered brain metabolism with increased myo-inositol concentrations and greater generalized anxiety symptoms accompanied by elevated myo-inositol. [8]
Systemic inflammatory responses and/or ultrafine particles (from TRAP) that reach the brain and result in neurodevelopmental delays are suspected to trigger neuroinflammation with brain damage exerted through many possible mechanisms including oxidative stress, mitochondrial dysfunction and glutamatergic excitotoxicity.[8]
Serum C-reactive protein (CRP) was positively correlated with cerebral myo-inositol in subjects over 55 years old. Myo-inositol is mainly found in astrocytes, and increases are a result of central nervous system damage. Low grade systemic inflammation mediated by CRP may lead to increased BBB permeability. A compromised BBB may lead to release of inflammatory factors into the peripheral blood which may contain markers indicative of neurodegenerative diseases. [9]
Inositol & Sleep
Lower frontal cortex myo-inositol may indicate a disturbed second messenger system and may be linked to the pathophysiology of depression and co-occurring sleep symptoms among maturing adolescents. Short sleep and daytime sleepiness may be associated with frontal cortex myo-inositol independently from depression. [11]
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[1] National Center for Biotechnology Information. PubChem Compound Summary for CID 892, Inositol. https://pubchem.ncbi.nlm.nih.gov/compound/Inositol. Accessed Sept. 18, 2021.
[2]Hallman M, Bry K, Hoppu K, Lappi M, Pohjavuori M. Inositol supplementation in premature infants with respiratory distress syndrome. N Engl J Med. 1992;326(19):1233-9.
[3] Clements RS, Darnell B. Myo-inositol content of common foods: development of a high-myo-inositol diet. Am J Clin Nutr. 1980;33(9):1954-67.
[4] Chiappelli J, Rowland LM, Wijtenburg SA, et al. Evaluation of Myo-Inositol as a Potential Biomarker for Depression in Schizophrenia. Neuropsychopharmacology. 2015;40(9):2157-64.
[5] Larner J, Brautigan DL, Thorner MO. D-chiro-inositol glycans in insulin signaling and insulin resistance. Mol Med. 2010;16(11-12):543-52.
[6] Dinicola S, Minini M, Unfer V, Verna R, Cucina A, Bizzarri M. Nutritional and Acquired Deficiencies in Inositol Bioavailability. Correlations with Metabolic Disorders. Int J Mol Sci. 2017;18(10):E2187.
[7] Inositol. Fullscript.com. Published May 14, 2020. Accessed September 18, 2021. https://fullscript.com/ingredient/inositol
[8] Brunst KJ, Ryan PH, Altaye M, et al. Myo-inositol mediates the effects of traffic-related air pollution on generalized anxiety symptoms at age 12 years. Environ Res. 2019;175:71-8.
[9] Ge X, Xu XY, Feng CH, Wang Y, Li YL, Feng B. Relationships among serum C-reactive protein, receptor for advanced glycation products, metabolic dysfunction, and cognitive impairments. BMC Neurol. 2013;13:110.
[10] Lepore E, Lauretta R, Bianchini M, Mormando M, Di Lorenzo C, Unfer V. Inositols Depletion and Resistance: Principal Mechanisms and Therapeutic Strategies. Int J Mol Sci. 2021;22(13):6796.
[11] Urrila AS, Hakkarainen A, Castaneda A, Paunio T, Marttunen M, Lundbom N. Frontal Cortex Myo-Inositol Is Associated with Sleep and Depression in Adolescents: A Proton Magnetic Resonance Spectroscopy Study. Neuropsychobiology. 2017;75(1):21-31.
