Vitamin B1 (Thiamin)
What is Vitamin B1 (Thiamin)?
Thiamin is a water-soluble vitamin more commonly known as Vitamin B1. Thiamin is important for most tissues and organs in our bodies. Individuals with autism may not consume enough, may have higher needs, or may not absorb it well due to gut issues. For these reasons, appropriate intake should be considered.
The body needs thiamin for energy metabolism, growth, and healthy cell function. Thiamin is essential for the proper function of most tissues and organs including the brain and heart, and is also vital for our nervous and cardiovascular systems. [1]
Most of the thiamin found in our foods must be activated (hydrolyzed) in our small intestine in order for it to be absorbed. Children with autism may not be able to utilize thiamin well due to abnormal tissue handling and/or poor absorption from gut microbiota [5]. (see Gastrointestinal Issues)
Thiamin can be stored in small amounts in the liver, but it doesn’t last very long, which means there is a continuous need for it to be ingested to keep levels in the normal range.
Children with autism have altered food consumption (see: picky eating) and nutritional intake compared to typically developing children which can lead to vitamin B1 deficiency [2-4]
Sources of Thiamin
It’s important to note that cooking or heat processing reduces thiamin content in foods. Coffee and tea may also affect the absorption of thiamin. [1]
Foods such as pastas, grains, and breads may be enriched with thiamin. Those who are sensitive to fortified B vitamins or have methylation issues should avoid such grains and consume natural sources instead (listed above).
Recommended Intake
These recommendations are based off of 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.
Males
o-6 months: 0.2 mg/d
7-12 months: 0.3 mg/d
1-3 years: 0.5 mg/d
4-8 years: 0.6 mg/d
9-13 years: 0.9 mg/d
14-18 years: 1.2 mg/d
19-50 years: 1.2 mg/d
51+ years: 1.2 mg/d
Females
o-6 months: 0.2 mg/d
7-12 months: 0.3 mg/d
1-3 years: 0.5 mg/d
4-8 years: 0.6 mg/d
9-13 years: 0.9 mg/d
14-18 years: 1.1 mg/d
19-50 years: 1.1 mg/d
Pregnancy: 1.4 mg/d
51+ years: 1.1 mg/d
Deficiency
Low dietary intake of thiamin can cause a deficiency. Deficiency can also occur from certain conditions like alcohol dependence, HIV/AIDS, or the use of certain medication.
Symptoms of early thiamin deficiency:
Weight loss and anorexia
Confusion
Short-term memory loss
Muscle weakness
Cardiovascular symptoms like an enlarged heart
People at high risk of thiamin deficiency include:
Individuals with low intake possibly due to restrictive diets
People with alcohol dependency
Older adults
Individuals with HIV/AIDS
Individuals with diabetes (type 1 & type 2)
Thiamin Deficiency Syndromes
Wernicke-Korsakoff Syndrome:
This syndrome is most common among individuals with alcohol dependency, but can also be seen in people with severe gastrointestinal disorders, drug use, rapidly progressing malignancies or AIDS. This condition is caused by chronic thiamine deficiency and can cause permanent brain or nerve damage.
BeriBeri:
Significant thiamin deficiency causes a condition called beriberi. This condition causes peripheral neuropathy and wasting. Beriberi is rare in developed countries, but can still occur. Beriberi can often quickly be cured with increased thiamin intake. Beriberi can be “wet” or “dry”. “Dry” beriberi is primarily characterized by neurologic manifestations (like weakness or paralysis), while “wet” beriberi can cause cardiac effects and hypotension. A newly described form of beriberi has been discovered called “gastrointestinal beriberi” which includes nausea and vomiting, abdominal pain, and lactic acidosis [1].
Toxicity
Since thiamin is a water-soluble vitamin, excess thiamin is excreted in the urine. There is no established upper level for how much thiamin can be taken due to no recorded side effects. The body reduces the amount absorbed after an intake of 5 mg.
Supplements
Thiamin is available in dietary supplements including multivitamins, B-complex supplements, or as an isolated vitamin.
Examples
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.
Thiamin & Autism in the Research
Thiamin Intake
Children with autism have altered food consumption and nutritional intake compared to typically developing children which can lead to thiamin deficiency. [2-4]
Thiamin Metabolism and Excretion
Children with autism had normal plasma and urinary thiamine levels whereas plasma thiamine (TPP) concentration was decreased. The latter may be linked to abnormal tissue handling and/or absorption from gut microbiota of TPP [5].
Individuals with autism may have increased thiamin losses and oxidative stress [4]
Thiamin Supplementation
Supplementation can be beneficial for some individuals with autism, correcting for these losses [4,6].
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[1] Kerns JC, Gutierrez JL. Thiamin. Adv Nutr. 2017;8(2):395-397.
[2] Esteban-figuerola P, Canals J, Fernández-cao JC, Arija val V. Differences in food consumption and nutritional intake between children with autism spectrum disorders and typically developing children: A meta-analysis. Autism. 2019;23(5):1079-1095.
[3] Malhi P, Venkatesh L, Bharti B, Singhi P. Feeding Problems and Nutrient Intake in Children with and without Autism: A Comparative Study. Indian J Pediatr. 2017;84(4):283-288.
[4] Obrenovich ME, Shola D, Schroedel K, Agrahari A, Lonsdale D. The role of trace elements, thiamin (e) and transketolase in autism and autistic spectrum disorder. Front Biosci (Elite Ed). 2015;7:229-41.
[5] Anwar A, Marini M, Abruzzo PM, et al. Quantitation of plasma thiamine, related metabolites and plasma protein oxidative damage markers in children with autism spectrum disorder and healthy controls. Free Radic Res. 2016;50(sup1):S85-S90.
[6] Baird JS, Ravindranath TM. Vitamin B deficiencies in a critically ill autistic child with a restricted diet. Nutr Clin Pract. 2015;30(1):100-3.
Authors
April Allen, RDN
Brittyn Coleman, MS, RDN/LD, CLT
