Hypothyroidism: Effects of Vitamin D and B12 Deficiency
Learn how vitamin D and B12 deficiencies exacerbate hypothyroidism. Explore causes, symptoms, diagnostic tests, treatment options, and dietary tips for managing these deficiencies and improving thyroid health.
Written by Dr Sonia Bhatt
Last updated on 12th Mar, 2025
Hypothyroidism is an endocrine disorder in which the thyroid gland releases low levels of hormones. The condition affects the human body in several ways by affecting bone health, metabolism, etc. Individuals with low vitamin levels in their bodies may develop an autoimmune disease named Hashimoto’s thyroiditis that increases the risks of hypothyroidism.
Read on to learn more about the connection between hypothyroidism and vitamin D and B12 and how to manage their levels for a healthy thyroid function.
Causes and Symptoms of Hypothyroidism
Hypothyroidism is mainly caused by autoimmune conditions like Hashimoto’s thyroiditis. In this disease, the thyroid gland of a person is attacked by the immune system, causing low hormone production.
Apart from this, several other factors like iodine deficiency, removal of the thyroid gland through surgery, radiation therapy, certain medicines, etc. also cause hypothyroidism.
The symptoms of hypothyroidism may be present in individuals experiencing the following:
- Cold sensitivity
- Weight gain
- Skin dryness
- Thin and dry hair
- Fatigue
- Constipation
- Depression
- Memory loss, etc.
Vitamin D Deficiency: Causes and Symptoms
A person’s body may lack the required amount of vitamin D due to several factors. A deficiency of vitamin D shows some specific signs and symptoms that help one identify the condition.
Causes of Vitamin D Deficiency
Here are some of the reasons that lead to vitamin D deficiency in one’s body:
- The body is unable to absorb or utilise vitamin D properly
- Low source of vitamin D in the diet
- Not getting enough exposure to sunlight
Some other causes also include:
- Surgery for weight loss
- Intaking certain medicines
- Medical conditions like obesity, cystic fibrosis, liver and kidney diseases, etc.
Symptoms and Health Risks of Low Vitamin D
The common symptoms of low vitamin D include the following:
- Bone Pain
- Fatigue
- Muscle cramps or aches due to weakness
- Mood swings
- Depression
Lack of vitamin D leads to rickets in children. Thus, the following rickets symptoms also indicate vitamin D deficiency:
- Bent or bowed bones affecting the growth pattern
- Weak muscles
- Deformities in bone joints, etc.
Vitamin B12 Deficiency: Causes and Symptoms
Several factors lead to vitamin B12 deficiency in the human body including low sources of vitamin B12 in the diet. Knowing the causes and symptoms of vitamin B12 deficiency is essential for timely prognosis.
Causes of Vitamin B12 Deficiency
The following are the common causes of vitamin B12 deficiency:
- Pernicious anaemia
- Digestive diseases
- Gastritis
- Disorders from alcohol consumption
- Low source of vitamin B12 in the diet, etc.
Symptoms and Health Risks of Vitamin B12 Deficiency
Here are the signs that help identify the symptoms of vitamin B12 deficiency in a human being:
| Physical Symptoms | Neurological Symptoms | Psychological Symptoms |
|
|
|
Relationship Between Hypothyroidism and Vitamin Deficiencies
Hypothyroidism affects the absorption of vitamins in a person's body, causing deficiencies in certain vitamins.
How Is Hypothyroidism Related to Vitamin D?
Vitamin D is known for its immune-regulating properties. If the immune system fails to function properly due to low levels of vitamin D, it may mistakenly attack the thyroid gland and affect hormone production.
Thus, deficiency of this vitamin can lead to autoimmune diseases like Grave’s disease and Hashimoto’s thyroiditis, which are the primary causes of hypothyroidism.
How Does Hypothyroidism Affect Vitamin B12 Levels?
As per research, people with hypothyroidism have lower levels of vitamin B12 than normal ones. Individuals with hypothyroidism have anti-parietal cell antibodies in their body which compromises vitamin B12 absorption. This causes a deficiency of the specific vitamin.
As per records, individuals with hypothyroidism have almost 27% vitamin B12 deficiency.
Diagnosis and Testing: Hypothyroidism, Vitamin D, and B12
Proper diagnosis and testing procedures can help detect the causes of hypothyroidism at an early stage, leaving enough scope for treatment.
Diagnostic Tests for Hypothyroidism
Hypothyroidism can be diagnosed through blood tests. Doctors suggest thyroid blood tests to check the levels of thyroxine (T4), triiodothyronine (T3), and thyroid-stimulating hormone (TSH) in one’s blood. Low levels of T3 and T4 indicate hypothyroidism in individuals.
Other tests for hypothyroidism include imaging tests like ultrasound, radioactive iodine uptake, etc.
Vitamin D and B12 Level Testing
Patients diagnosed with hypothyroidism should opt for routine vitamin D and B12 level tests to keep track of their health conditions. Following are the methods to check these vitamin levels in one’s body:
- 25-hydroxyvitamin D, also known as 25(OH)D is a blood test to determine vitamin D levels in one’s body.
- Serum B12 to determine vitamin B12 levels in the body.
- A complete blood count test helps determine whether the patient has anaemia, a common sign of vitamin B12 deficiency, or not.
Get Your Thyroid Symptoms Checked
Treatment and Management of Hypothyroidism and Vitamin Deficiencies
Proper treatment and medication can keep hypothyroidism under control and also normalise the vitamin D and B12 levels in one’s body.
Management of Hypothyroidism
The main treatment of hypothyroidism includes adding synthetic hormones to one’s body to replace the thyroid hormone deficiency. Levothyroxine is prescribed by doctors to treat hypothyroidism. However, the patients need to continue this medicine for a lifetime to maintain the hormone levels.
Treatment for Vitamin D Deficiency
The deficiency of vitamin D can be treated with supplements for this vitamin. Doctors suggest medications like D2 (ergocalciferol) and D3 (cholecalciferol) to treat vitamin D deficiency based on the requirements of the patient.
Treatment for Vitamin B12 Deficiency
The treatment for vitamin B12 deficiency depends on the cause of the condition. Doctors may prescribe vitamin B12 oral medicines, nasal gel, nasal spray, or intramuscular injections depending on the patient’s needs.
Dietary Considerations to treat Hypothyroidism and Vitamin Deficiencies
Apart from medications, one can also intake foods rich in vitamin D and B12 to suffice the deficiency of these nutrients.
Foods Rich in Vitamin D
Here are some of the vitamin D-enriched foods that one can intake:
- Egg yolks
- Mushrooms
- Cod liver oil
- Rainbow trout
- Salmon, sardines, tuna, and other fatty fish
- Foods like cow milk, almond milk, oat milk, soy milk, breakfast cereals, and dairy products also contain vitamin D.
Foods Rich in Vitamin B12
Here are some of the vitamin B12-enriched foods to increase the vitamin level in the body:
- Eggs
- Milk
- Fish
- Meat
- Dairy products
- Fortified foods like plant milk, nutritional yeast, breakfast cereals, etc.
Impact of Diet on Hypothyroidism
To normalise hypothyroidism, one can include the following foods in their diet:
- Selenium-rich foods like Brazil nuts, tuna, turkey
- Foods rich in vitamin B12 like cheese, peas, eggs, sesame seeds, beans, etc.
- For hypothyroidism caused due to iodine deficiency, one should include iodine-rich foods like seafood, seaweed, banana, iodised salts, etc. in their diet.
Lifestyle and Preventive Measures to Manage Vitamin Deficiencies
Regular monitoring of thyroid hormone levels along with vitamin D and B12 status is crucial for effective hypothyroidism management. Besides medications and tests, one can engage in regular physical activities to improve overall well-being.
Sunlight is a great source of vitamin D. Thus, moderate sun exposure helps maintain adequate levels of this micronutrient. One can make significant lifestyle changes through stress management techniques such as yoga, meditation, adequate sleep hygiene, and a balanced diet to manage symptoms associated with hypothyroidism.
Conclusion
Deficiencies of vitamin D and B12 can affect hypothyroidism by making the condition more severe. It is essential to diagnose the condition upon noticing the related symptoms. Identifying these underlying causes of hypothyroidism provides more opportunities for better treatment and care.
Consult Top Endocrinologist
Get Your Thyroid Symptoms Checked
₹620(₹1550)60% off
₹536(₹1341)60% off
₹2364(₹5910)60% off
₹2472(₹6179)60% off
₹1935(₹4500)57% off
Member price₹1451(₹3375)57% off
Member price₹1612(₹4029)60% off
Consult Top Endocrinologist
Dr. Nithin Reddy Modhugu
Endocrinologist
6 Years • MBBS, MD (General Medicine), DNB (Endocrinology)
Hyderabad
Dr. Nithin's Endocrine Clinic, Hyderabad
(75+ Patients)
Dr. Gayatri S
Endocrinologist
4 Years • Suggested Qualifictaion- MBBS, MD (Internal Medicine), DM (ENDOCRINOLOGY)
Nellore
Narayana hospital, Nellore
Dr. Venkata Rakesh Chintala
Endocrinologist
8 Years • MBBS,MD( GEN MEDICINE), DM ( ENDOCRINOLOGY)
Krishna district
Sanjeevani Hospital, Krishna district
Dr. Arunava Ghosh
General Physician/ Internal Medicine Specialist
9 Years • MBBS,MD(GENL.MED.),DM(ENDOCRINOLOGY)
Kolkata
VDC Clinic, Kolkata
Dr. Shiva Madan
Endocrinologist
10 Years • MBBS , MD (General medicine) , DM (Endocrinology)
Bikaner
Sushma diabetes and Endocrine center, Bikaner
