You have been diagnosed with an underactive thyroid or Hypothyroidism. Your physician put you on Levothyroxine (Synthroid, L-T4), your blood work has regulated (normal TSH), but you still have hypothyroid symptoms. Sounds familiar? I see this very frequently in my practice, and if your thyroid has been treated appropriately you shouldn’t have to continue to struggle with fatigue, brain fog, weight gain, hair loss, etc.
Levothyroxine is the #1 prescribed medication in North America. It is a synthetic form of T4, and is prescribed for underactive thyroid diseases, such as hypothyroidism and Hashimoto’s. As many as 15% or more of patients still complain of hypothyroid symptoms, even when blood tests (i.e. TSH) suggest that the thyroid function is normal. An elevated TSH in the blood is how physicians generally diagnose hypothyroidism, and they ‘treat’ it by prescribing or increasing Levothyroxine dose until TSH levels are back in the normal range. Patient symptoms are not typically used in judging the adequacy of treatment, TSH is.
Symptoms of Hypothyroidism:
– Weight gain
– Hair loss
– Dry skin and hair
– Thinning of lateral eyebrows
– Increased sensitivity to cold
– Sore muscles and joints
– Anxiety, depression
– Impaired memory and focus
– Slow heart rate
If you are taking Levothyroxine, your thyroid panel is normal on blood work and you still have symptoms of hypothyroidism, it is important to figure out why that is, so that you can properly support your thyroid function and feel better.
Below are a few reasons as to why you may still be symptomatic on your thyroid medication.
Levothyroxine dose is too low and lab test ranges are too wide
- TSH; reference range is 0.32-4.0 mIU/L, optimal range is 0.8-2.5 mIU/L.
- Free T4; reference range is 9-19 pmol/L, optimal range is 14-19 pmol/L
If your TSH is higher than the optimal range and your free T4 is lower than the optimal range, that indicates that your levothyroxine dose is too low, but this commonly goes unnoticed because physicians assess based on reference ranges.
Not taking your medication appropriately
You can decrease the absorption of levothyroxine by not following the following recommendations:
- Take on an empty stomach, at least one hour away from food
- Eat fiber at least one hour after taking thyroid medication
- Take away from iron, calcium and multivitamins – take 4 hours away from calcium, and 2-3 hours away from iron supplements
- Don’t eat raw goitrogens (i.e. brussel sprouts, broccoli, cauliflower, cabbage) in large amounts. They block conversion of T4 to T3 and prevent secretion of thyroid hormones.
- Take at least 2 hours away from antacids
- Take away from Estrogen, in the form of hormone replacement therapy or Birth control pill
Poor conversion of T4 to T3
Your thyroid gland makes two thyroid hormones, T4 (thyroxine) and T3 (triiodothyronine). T4 is a prohormone and is relatively inactive. It is converted into T3, the active thyroid hormone, in the body. As much as 80% of T4 is converted to T3. T3 is three to five times more potent than T4. So the efficient conversion of T4 to T3 is critical, and levels of circulating “free” T3 are essential to wellbeing. Therefore, it is important to test for free T3, since levothyroxine only contains T4, and your body still has to covert that T4 to T3. If your free T3 levels are low on blood work, then that would explain why you are still experiencing hypothyroid symptoms. There are nutrients that can help with T4 to T3 conversion, such as selenium, zinc, iodine. Dessicated thyroid contains both T3 and T4, and can be prescribed by some physicians and naturopathic doctors with prescribing rights.
Stress affects your thyroid function
When we are stressed, our body’s metabolism slows down by suppressing the thyroid function. Increased cortisol, the stress hormone, causes TSH suppression, which decreases levels of T4 and T3. Also, the conversion of T4 to T3 slows down, leading to higher levels of reverse T3. Although not routinely measured by physicians, you can request to measure your reverse T3 levels on a blood test to see whether your stress and adrenal function are contributing to your thyroid health.
In Hashimoto’s disease thyroid antibodies are elevated, specifically Anti-TPO. This happens when our immune system attacks the thyroid gland, and decreases its function. The most common cause of hypothyroidism is Hashimoto’s, but it is greatly underdiagnosed or misdiagnosed because physicians typically don’t order Anti-TPO is part of their routine thyroid screen. At the beginning stages of Hashimoto’s it is common that all thyroid markers are within normal range, except for Anti-TPO. Addressing the autoimmune component of Hashimoto’s is vital in restoring the thyroid function.
If you have been on thyroid medication and you still feel unwell, despite ‘normal’ blood work, know that there is hope. You likely need another approach, one that will help you figure out the cause of your symptoms and once that is addressed, you can start to regain your optimal health back.
Check out more from Dr. Tatiana on hypothyroidism and Hashimoto’s, or request a consultation for more personalized guidance.