sex hormones

thyroid

DIO1

A Gene That Activates Thyroid Hormones (DIO1)

Written by Aleksa Ristic, MS (Pharmacy) on August 20th, 2019

Scientists have identified one DIO1 variant associated with the levels of T3, an active thyroid hormone. Read on to check your DIO1 gene and get tailored recommendations to support the thyroid.

What do Low Thyroid Hormones Look Like?

The typical symptoms of low thyroid hormones or hypothyroidism include [R]:

Cold intolerance
Dry skin
Weight gain
Fatigue
Constipation

Thyroid issues top the list of endocrine disorders, with around 20 million Americans being affected [R].

Levothyroxine (synthetic T4) for hypothyroidism is the second most prescribed drug in the US [R].

Lab Tests

Doctors usually test T4 and TSH to diagnose hypothyroidism. Low thyroid hormones lead to a compensatory increase in TSH, which stimulates the thyroid to produce more [R].

As you are about to see, total and free T3 levels can also be crucial for making the right diagnosis [R].

Genetics

Do genetics play a role in this thyroid disease “epidemic?” Given that genetic mutations account for up to 50-90% of thyroid hormone variations, the answer is yes [R].

Different genes impact the production, release, and metabolism of thyroid hormones and may thus correlate with thyroid disorders.

Hypothyroidism manifests with cold intolerance, weight gain, and fatigue. Suggested lab tests are TSH, T3, and T4. Different genes are associated with thyroid hormone variations and related disorders.

HapMap Data Underlines One DIO1 Variant

Out of various genes that impact thyroid health, a study published in the Journal of Clinical Endocrinology & Metabolism focused on DIO1 (deiodinase 1), a gene that controls the activation of thyroid hormones.

Based on the data from over 3,000 individuals, the researchers identified one variant, rs2235544, that correlates with thyroid hormones. More precisely, carriers of the “C” allele have higher levels of T3, which is the active form [R].

Studies have identified another variant in the same gene, rs11206244, but its effects are less significant and stem from a correlation with the SNP mentioned above [R, R].

DIO1 (deiodinase 1) gene controls the activation of thyroid hormones. In one clinical trial, carriers of the “C” allele on rs2235544 had higher levels of the active form, T3.

How It Works

The DIO1 gene encodes an enzyme that converts T4 (thyroxine) to T3 (triiodothyronine), the active thyroid hormone. DIO1 is also involved in the degradation of both T3 and T4. Less DIO1 means less T3 and more T4, resulting in a lower activity of thyroid hormones [R].

DIO1 requires a complex of selenium and cysteine for its optimal function, which makes it a so-called selenoenzyme [R, R, R].

Carriers of the “C” allele on rs2235544 have increased expression of DIO1, which may increase the activity of thyroid hormones [R, R].

DIO1 encodes a selenium-dependent enzyme that converts T4 to active T3. The “C” allele on rs2235544 boosts the expression of DIO1, and it’s associated with higher T3 levels.

Your DIO1 Results for Hypothyroidism

SNP Summary

DIO1 rs2235544 [R]

‘A’ = normal DIO1 activity and T3 levels
‘C’ = more active DIO1, correlates with higher T3 levels

SNP Table

variant	genotype	frequency	risk allele
rs2235544

Recommendations

Lifestyle & Health Conditions

Environmental toxins such as pesticides, bisphenol-A, heavy metals, and flame retardants can prevent thyroid hormone activation by inhibiting DIO1. This may be one of the reasons for thyroid disorder epidemics in today’s industrialized world [R].

Try your best to avoid the above toxins in order to optimize your thyroid health.

Conditions that can suppress DIO1 include [R]:

Address any of the above conditions that may be lurking behind thyroid issues.

You can increase DIO1 activity by avoiding toxins such as pesticides, bisphenol-A, and heavy metals. Conditions that suppress DIO1 include stress, depression, obesity, and diabetes.

Diet

As mentioned, selenium and cysteine are crucial for DIO1 activity, so you want to pay special attention to these nutrients. In one study, selenium-deficient rats retained only 6-13% of DIO1 activity [R].

Brazil nuts are loaded with selenium—a few pieces daily will supply the required amount. You can obtain cysteine from protein-rich foods such as [R, R]:

Meat
Chicken
Fish
Eggs
Whey

Consuming enough selenium from Brazil nuts and cysteine from protein-rich foods (such as meat, fish, and eggs) may increase DIO1 activity, but more research is needed to confirm this.

Supplements

Selenium [R]
NAC (as a source of cysteine) [R]

Keep in mind that the above supplements can’t replace a balanced diet, and they’re not approved for the prevention or treatment of thyroid conditions.

Aleksa Ristic

MS (Pharmacy)

Aleksa received his MS in Pharmacy from the University of Belgrade, his master thesis focusing on protein sources in plant-based diets.

Aleksa is passionate about herbal pharmacy, nutrition, and functional medicine. He found a way to merge his two biggest passions—writing and health—and use them for noble purposes. His mission is to bridge the gap between science and everyday life, helping readers improve their health and feel better.

Disclaimer

The information on this website has not been evaluated by the Food & Drug Administration or any other official medical body. This information is presented for educational purposes only, and may not be used to diagnose or treat any illness or disease.

Also keep in mind that the “Risk Score” presented in this post is based only on a select number of SNPs, and therefore only represents a small portion of your total risk as an individual. Furthermore, these analyses are based primarily on associational studies, which do not necessarily imply causation. Finally, many other (non-genetic) factors can also play a significant role in the development of a disease or health condition — therefore, carrying any of the risk-associated genotypes discussed in this post does not necessarily mean you are at increased risk of developing a major health condition.

Always consult your doctor before acting on any information or recommendations discussed in this post — especially if you are pregnant, nursing, taking medication, or have been officially diagnosed with a medical condition.

More sex hormones blogs

A Gene That Activates Thyroid Hormones (DIO1) A Surprising Genetic Link to Thyroid Hormones (PDE8B) The Role of Genes in Thyroid Autoimmunity (PTPN22) Why Do Some People Have Better Thyroid Health? (FOXE1) The Gene Associated with "Hidden Hypothyroidism" (DIO2) What’s the Link Between This Gene and Thyroid Autoimmunity? (TSHR) Can This Gene Contribute To Autoimmune Thyroid Disorders? (STAT3) Is This Gene Connected To Autoimmunity And Thyroid Health? (SH2B3) How This Autoimmunity Gene Impacts Thyroid Health (CTLA4) How a Cell Structure Gene Impacts Thyroid Health (CAPZB)

More thyroid blogs

Content

What do Low Thyroid Hormones Look Like? HapMap Data Underlines One DIO1 Variant Your DIO1 Results for Hypothyroidism

Unlock Personalized Results And So Much More!

Shipping Worldwide

30-Days Money-Back Guarantee*

HSA/FSA Eligible

Essential Bundle

SelfDecode DNA Kit

24/7 AI Health Coach
1250+ Comprehensive DNA Health Reports
Personalized Diet, Supplement, & Lifestyle Recommendations
Lifestyle Risk Assessments
Unlimited access to Labs Analyzer

$418

$376

Men's Health Month 10% Off

Essential

Bundle

Everything in essential
SelfDecode DNA Kit
Methylation Pathway
+130 Medical Reports
25+ Longevity Screener Risk Assessments

Odds ratios to evaluate your risk for 25+ medical conditions
10-year risk scores to prioritize health conditions
Lifetime risk scores to plan for long-term health

$667

$566

Men's Health Month 15% Off

Men's Health Month 30% Off

Ultimate Bundle

Everything in essential+
SelfDecode DNA Kit
Medication Check (PGx testing) for 50+ medications
40+ Family Planning (Carrier Status) Reports
Ancestry Percentages
Mitochondrial Ancestry

$894

$625

* SelfDecode DNA kits are non-refundable. If you choose to cancel your plan within 30 days you will not be refunded the cost of the kit.

We will never share your data

We follow HIPAA and GDPR policies

We have World-Class Encryption & Security

People Love Us

Rated 4.7/5 from 750+ reviews

People Trust Us

200,000+ users, 2,000+ doctors & 80+ businesses

SelfDecode is a personalized health report service, which enables users to obtain detailed information and reports based on their genome. SelfDecode strongly encourages those who use our service to consult and work with an experienced healthcare provider as our services are not to replace the relationship with a licensed doctor or regular medical screenings.

Policies

About

Support
Our Team
Affiliate Program
Privacy
Media