Why You’re Exhausted: The Iron–Thyroid Connection No One Talks About
By Bella Del Medico, MS, RDN, LDN | April 2026 | 5 min read | Energy + Thyroid Health
If you’re constantly feeling tired—even after a full night of sleep—it’s easy to blame stress, a busy schedule, or not drinking enough coffee. But one of the most overlooked root causes of fatigue is the connection between iron levels and thyroid function.
The Role of Iron in Energy Production
Iron plays a critical role in carrying oxygen throughout your body. It’s a key component of hemoglobin, which helps deliver oxygen to your cells for energy production.
When iron levels are low, your body has to work harder to function. This can result in:
Fatigue and low energy
Shortness of breath
Brain fog
Cold intolerance
Even if your labs don’t show anemia, low iron stores (low ferritin) can still be a hidden cause of fatigue. Think of ferritin as your “iron storage tank,” as it represents how much iron your body has in reserve rather than circulating.
The Thyroid’s Role in Metabolism
Your thyroid is responsible for regulating your metabolism—essentially how your body produces and uses energy.
When thyroid function is sluggish (often referred to as hypothyroidism), you may experience:
Constant fatigue
Weight gain or difficulty losing weight
Dry skin and hair
Feeling cold all the time
But here’s where it gets interesting…
The Iron–Thyroid Connection Explained
Iron is actually required for proper thyroid hormone production.
Specifically, iron supports an enzyme called thyroid peroxidase (TPO), which helps your body produce thyroid hormones. Without enough iron, this process becomes less efficient.
As a result, low iron can contribute to low thyroid function; low thyroid function can worsen fatigue
It’s a cycle that often goes unnoticed. Many people are told their labs are “normal,” but standard ranges don’t always reflect optimal levels—especially for ferritin (iron stores).
So if you are eating well, sleeping enough, and trying to manage stress…but STILL feel off, it may be because your body doesn’t have the nutrients it needs to function properly.
Now, you are probably wondering, “How can I support Iron AND thyroid health everyday?”
Inside my practice, Ingredients for Life, I help you:
Identify underlying nutrient imbalances
Understand your labs beyond “normal”
Build a personalized nutrition plan to restore your energy
If you’re ready to stop guessing and start feeling better, book a 1:1 session with me to explore what your body truly needs.
You deserve to feel energized, clear, and like yourself again.