There’s increasing evidence to suggest that low levels of vitamin D (deficiency of Vitamin D ) may play a role in thyroid disorders. For instance, research has suggested a possible link between vitamin D deficiency and autoimmune thyroid disorders, the most common cause of hypothyroidism (underactive thyroid).
People with hypothyroidism who took extra vitamin D supplements for 12 weeks had improvements in blood levels of thyroid-stimulating hormone.
What is vitamin D?
The body can make its own vitamin D from sunlight. However, adequate vitamin D can also be obtained from supplements and a small amount comes from a few foods. Vitamin D has to be changed by the body a number of times before it can be used.
What does vitamin D do?
What does vitamin d deficiency cause?
Some of the functions of the body that vitamin D has been linked with include:
Healthy heart and circulation
Vitamin d levels
The following table provides rough range trusted sources for low, normal, and high vitamin D levels for the average adult in nmol/ml and ng/ml.
|Level||Blood test result|
|Low||30 nmol/l or 12 ng/ml or below|
|Adequate||50 nmol/l or 20 ng/ml or above|
|High||125 nmol/l or 50 ng/ml or above|
Is vitamin d from the sun?
Diet is an issue too. Very few foods are natural sources of vitamin D, and although a variety of common foods are fortified with D, they provide relatively small amounts.
Cod liver oil (1 tablespoon): 1,360 IU
Swordfish (3 ounces, cooked): 566 IU
Salmon (3 ounces, cooked): 447 IU
Tuna fish (3 ounces water-packed): 154 IU
Orange juice, fortified (1 cup): 137 IU
Nonfat milk, fortified (1 cup): 115 to 124 IU
Yogurt, fortified (6 ounces): 80 IU
Sardines (2 pieces, drained): 46 IU
Beef liver (3 ounces, cooked): 42 IU
Egg (1 large): 41 IU
Cereal, fortified (1 cup): 40 IU
Does vitamin D or its deficiency have a role in the development of thyroid diseases?
Some, but not all, observational studies have found low blood levels of vitamin D in patients with hypothyroidism (underactive thyroid) as well as hyperthyroidism (an overactive thyroid) due to Gravesʼ disease.
It is not clear from these studies if low vitamin D is a cause, a consequence of an innocent bystander in the development of these common thyroid conditions.
It is possible that low vitamin D may permit the under-performing immune system to facilitate the progression of thyroid disease.
Thyroid stimulating hormone – Thyroid nodule symptoms
Equally, it is also possible that people with thyroid diseases may have altered health or lifestyle that leads to a low vitamin D state. For example, patients with an over-active thyroid due to Gravesʼ disease may increase the breakdown of vitamin D into inactive products, whereas those with an underactive thyroid may spend less time outdoors due to tiredness and thus have reduced sun exposure.
Only properly conducted scientific trials will be able to answer this question in a definitive manner.
Should everyone be taking vitamin D supplements?
People found to have vitamin D deficiency may also be prescribed higher therapeutic doses following the appropriate testing and clinical management.
Summarize – Vitamin D recommendations
Much more research needs to be done before specific guidelines for using vitamin D to prevent or treat thyroid disease are established by the medical community. However, given the growing understanding of how important vitamin D is to overall health, it’s worth making sure you’re getting enough of it.
You might even want to talk to your doctor about testing you for a deficiency, especially if you have a thyroid condition or are at risk for one.