--- title: "Could Low Iron Be Causing Your Fatigue, Brain Fog, and Burnout?" entity: "blog" canonical_url: "https://www.onnalomd.com/blog/could-low-iron-be-causing-your-fatigue-brain-fog-and-burnout" markdown_url: "https://www.onnalomd.com/llms/blog/could-low-iron-be-causing-your-fatigue-brain-fog-and-burnout" lastmod: "2026-06-19T23:42:00.000Z" --- You wake up tired. By mid-afternoon, you're reaching for caffeine. You struggle to focus during meetings, your workouts feel harder than they used to, and despite sleeping seven or eight hours, you still don't feel rested. Maybe you've noticed more hair shedding in the shower. Maybe you've started waking up at 3 a.m. Or perhaps you've wondered if you're entering perimenopause because you simply don't feel like yourself anymore. As a functional medicine physician, I see this every day. Many women assume their symptoms are caused by stress, aging, hormones, or simply having too much on their plate. And while those factors absolutely matter, there is another common and often overlooked contributor to fatigue that deserves attention: Iron deficiency. The good news is that iron deficiency is often identifiable, measurable, and treatable. Yet many women spend years struggling before anyone checks the right markers. Let's talk about how to recognize it, what causes it, and how to support healthy iron levels naturally. ## Could Low Iron Be Causing Your Symptoms? Iron plays a critical role in transporting oxygen throughout the body. Every organ, muscle, hormone-producing gland, and brain cell depends on oxygen to function optimally. When iron stores become depleted, your body may still be functioning, but often not efficiently. This is where many women find themselves stuck. Their labs may be technically "normal." (between 12-150 ng/ml) Their doctor may tell them everything looks fine. Yet they continue to feel exhausted. Common symptoms of low iron include: - Fatigue that doesn't improve with rest - Brain fog and poor concentration - Hair loss or excessive hair shedding - Feeling cold when others are comfortable - Dizziness when standing - Poor exercise recovery - Shortness of breath during activity - Anxiety or heart palpitations - Restless legs - Brittle nails - Low motivation - Poor sleep quality Many of these symptoms overlap with burnout, perimenopause, thyroid dysfunction, and chronic stress, which is one reason iron deficiency is frequently overlooked. ## Why Women in Midlife Are Particularly Vulneraable Women have unique demands on their iron stores. Such as monthly menstrual blood loss, especially if periods are heavy. But there are other contributors that often fly under the radar: Chronic Stress Stress affects digestion, nutrient absorption, and inflammation. Even if you're eating well, your body may not be absorbing nutrients as efficiently when you're living in a constant state of overwhelm. Pregnancy and Postpartum Recovery Pregnancy places significant demands on iron stores, and some women never fully rebuild those reserves. Restrictive Diets Years of dieting, under-eating protein, vegetarian diets without careful planning, or simply being too busy to nourish yourself adequately can gradually deplete iron levels. Intense Exercise Endurance exercise and high training volumes can increase iron requirements and losses. Digestive Issues Conditions that affect gut health may reduce iron absorption even when intake appears adequate. ## The Lab Marker Many Women Don't Know About Ferritin measures your stored iron reserves. Many standard evaluations only look at hemoglobin and hematocrit through a complete blood count (CBC). The problem is that ferritin can become depleted long before anemia develops. In other words, you may be suffering from symptoms of low iron while still having a "normal" CBC. If you're experiencing persistent fatigue, brain fog, hair loss, poor exercise tolerance, or unexplained exhaustion, consider discussing the following labs with your healthcare provider: Iron Evaluation - Ferritin - Complete blood count (CBC) - Iron panel - Iron saturation - hs-CRP (because inflammation can falsely elevate ferritin) Nutrients That Work Alongside Iron - Vitamin B12 - Folate These nutrients are important for healthy red blood cell production and can contribute to similar symptoms when deficient. - Mild Iron Deficiency: Ferritin 30–50: - Moderate Deficiency : Ferritin 15–30: - Significant Deficiency: Ferritin <15 or anemia ## Foods That Naturally Support Healthy Iron Levels Iron-rich foods include: Heme Iron from Animal Sources (Most Easily Absorbed) - Beef - Bison - Lamb - Liver - Dark poultry - Seafood Plant Sources (Non-Heme Iron) - Lentils - Black beans - Pumpkin seeds - Spinach - Quinoa - Tofu - Blackstrap molasses - Spirulina ## Tips to Improve Iron Absorption It's not just about how much iron you consume. It's also about how much your body can absorbs. To improve absorption: - Pair iron-rich foods with vitamin C - Citrus fruits: Strawberries, Kiwi, Bell peppers, Lemon juice - Ensure adequate B12 and folate - Support healthy digestion - Avoid taking iron with coffee, tea, or calcium-rich foods - Taking Iron every other day, because of the effects of hepcidin (a hormone that blocks gut absorption of iron for 24 hours after you take iron) ## Supplementing with Iron Several studies in iron-deficient women found that alternate-day dosing resulted in greater fractional iron absorption than daily dosing. Best Forms of Iron 1. Iron Bisglycinate (often my favorite) Typical elemental iron: 25–30 mg per capsule Pros: - Better tolerated - Less constipation - Less nausea - Good absorption 2. Ferrous Sulfate Typical elemental iron: 65 mg elemental iron per 325 mg tablet Pros: - Most studied - Inexpensive Cons: - More constipation - More nausea and GI upset 3. Heme Iron Pros: - Excellent absorption - Less affected by food - Helpful when ferritin won't rise Cons: - More expensive - Animal-derived ## Iron-Supportive Smoothie This recipe combines iron-rich foods with vitamin C and protein to support absorption and overall nourishment. Ingredients: - ½ cup frozen blueberries - 2 tablespoons blackstrap molasses - 1 cup spinach - 2 tablespoons pumpkin seeds - 2 tablespoons hemp hearts - 1 kiwi or orange - 1 cup unsweetened almond milk - Juice from half a lemon - 1 serving protein powder (20+ grams protein) Blend until smooth. ### The Bigger Picture If you've been feeling exhausted despite normal labs, waking up tired, struggling with brain fog, or wondering why your body doesn't seem to bounce back the way it once did, low iron deserves consideration. Not because it's the only answer. But because it's often a missing piece. True vitality comes from understanding how all of the systems in the body work together—hormones (thyroid, cortisol, insulin), sleep, metabolism, gut health, stress, nutrient status, and recovery. Sometimes addressing one overlooked factor creates momentum everywhere else. ### Frequently Asked Questions #### Can low iron cause brain fog? Yes. Iron helps transport oxygen throughout the body, including the brain. Low iron levels may contribute to poor concentration, memory challenges, and mental fatigue. #### Can low iron affect sleep? It can. Some women with low iron experience restless legs, poor sleep quality, or difficulty feeling rested despite adequate sleep duration. #### What is ferritin and why is it important? Ferritin measures your stored iron reserves. It can become depleted before anemia develops, making it an important marker when evaluating unexplained fatigue. #### Can low iron feel like perimenopause? Absolutely. Fatigue, brain fog, anxiety, poor sleep, reduced exercise tolerance, and mood changes can occur with both low iron and perimenopause, which is why evaluating both is often important. You wake up tired. By mid-afternoon, you're reaching for caffeine. You struggle to focus during meetings, your workouts feel harder than they used to, and despite sleeping seven or eight hours, you still don't feel rested. Maybe you've noticed more hair shedding in the shower. Maybe you've started waking up at 3 a.m. Or perhaps you've wondered if you're entering perimenopause because you simply don't feel like yourself anymore. As a functional medicine physician, I see this every day. Many women assume their symptoms are caused by stress, aging, hormones, or simply having too much on their plate. And while those factors absolutely matter, there is another common and often overlooked contributor to fatigue that deserves attention: Iron deficiency. The good news is that iron deficiency is often identifiable, measurable, and treatable. Yet many women spend years struggling before anyone checks the right markers. Let's talk about how to recognize it, what causes it, and how to support healthy iron levels naturally. ### Could Low Iron Be Causing Your Symptoms? Iron plays a critical role in transporting oxygen throughout the body. Every organ, muscle, hormone-producing gland, and brain cell depends on oxygen to function optimally. When iron stores become depleted, your body may still be functioning, but often not efficiently. This is where many women find themselves stuck. Their labs may be technically "normal." (between 12-150 ng/ml) Their doctor may tell them everything looks fine. Yet they continue to feel exhausted. Common symptoms of low iron include: - Fatigue that doesn't improve with rest - Brain fog and poor concentration - Hair loss or excessive hair shedding - Feeling cold when others are comfortable - Dizziness when standing - Poor exercise recovery - Shortness of breath during activity - Anxiety or heart palpitations - Restless legs - Brittle nails - Low motivation - Poor sleep quality Many of these symptoms overlap with burnout, perimenopause, thyroid dysfunction, and chronic stress, which is one reason iron deficiency is frequently overlooked. ### Why Women in Midlife Are Particularly Vulnerable Women have unique demands on their iron stores. Such as monthly menstrual blood loss, especially if periods are heavy. But there are other contributors that often fly under the radar: Chronic Stress Stress affects digestion, nutrient absorption, and inflammation. Even if you're eating well, your body may not be absorbing nutrients as efficiently when you're living in a constant state of overwhelm. Pregnancy and Postpartum Recovery Pregnancy places significant demands on iron stores, and some women never fully rebuild those reserves. Restrictive Diets Years of dieting, under-eating protein, vegetarian diets without careful planning, or simply being too busy to nourish yourself adequately can gradually deplete iron levels. Intense Exercise Endurance exercise and high training volumes can increase iron requirements and losses. Digestive Issues Conditions that affect gut health may reduce iron absorption even when intake appears adequate. ### The Lab Marker Many Women Don't Know About Ferritin measures your stored iron reserves. Many standard evaluations only look at hemoglobin and hematocrit through a complete blood count (CBC). The problem is that ferritin can become depleted long before anemia develops. In other words, you may be suffering from symptoms of low iron while still having a "normal" CBC. If you're experiencing persistent fatigue, brain fog, hair loss, poor exercise tolerance, or unexplained exhaustion, consider discussing the following labs with your healthcare provider: Iron Evaluation - Ferritin - Complete blood count (CBC) - Iron panel - Iron saturation - hs-CRP (because inflammation can falsely elevate ferritin) Nutrients That Work Alongside Iron - Vitamin B12 - Folate These nutrients are important for healthy red blood cell production and can contribute to similar symptoms when deficient. - Mild Iron Deficiency: Ferritin 30–50: - Moderate Deficiency : Ferritin 15–30: - Significant Deficiency: Ferritin <15 or anemia ### Foods That Naturally Support Healthy Iron Levels Iron-rich foods include: Heme Iron from Animal Sources (Most Easily Absorbed) - Beef - Bison - Lamb - Liver - Dark poultry - Seafood Plant Sources (Non-Heme Iron) - Lentils - Black beans - Pumpkin seeds - Spinach - Quinoa - Tofu - Blackstrap molasses - Spirulina ### Tips to Improve Iron Absorption It's not just about how much iron you consume. It's also about how much your body can absorbs. To improve absorption: - Pair iron-rich foods with vitamin C - Citrus fruits: Strawberries, Kiwi, Bell peppers, Lemon juice - Ensure adequate B12 and folate - Support healthy digestion - Avoid taking iron with coffee, tea, or calcium-rich foods - Taking Iron every other day, because of the effects of hepcidin (a hormone that blocks gut absorption of iron for 24 hours after you take iron) ### Supplementing with Iron Several studies in iron-deficient women found that alternate-day dosing resulted in greater fractional iron absorption than daily dosing. Best Forms of Iron 1. Iron Bisglycinate (often my favorite) Typical elemental iron: 25–30 mg per capsule Pros: - Better tolerated - Less constipation - Less nausea - Good absorption 2. Ferrous Sulfate Typical elemental iron: 65 mg elemental iron per 325 mg tablet Pros: - Most studied - Inexpensive Cons: - More constipation - More nausea and GI upset 3. Heme Iron Pros: - Excellent absorption - Less affected by food - Helpful when ferritin won't rise Cons: - More expensive - Animal-derived ### Iron-Supportive Smoothie This recipe combines iron-rich foods with vitamin C and protein to support absorption and overall nourishment. Ingredients: - ½ cup frozen blueberries - 2 tablespoons blackstrap molasses - 1 cup spinach - 2 tablespoons pumpkin seeds - 2 tablespoons hemp hearts - 1 kiwi or orange - 1 cup unsweetened almond milk - Juice from half a lemon - 1 serving protein powder (20+ grams protein) Blend until smooth. ### The Bigger Picture If you've been feeling exhausted despite normal labs, waking up tired, struggling with brain fog, or wondering why your body doesn't seem to bounce back the way it once did, low iron deserves consideration. Not because it's the only answer. But because it's often a missing piece. True vitality comes from understanding how all of the systems in the body work together—hormones (thyroid, cortisol, insulin), sleep, metabolism, gut health, stress, nutrient status, and recovery. Sometimes addressing one overlooked factor creates momentum everywhere else. ### Frequently Asked Questions #### Can low iron cause brain fog? Yes. Iron helps transport oxygen throughout the body, including the brain. Low iron levels may contribute to poor concentration, memory challenges, and mental fatigue. #### Can low iron affect sleep? It can. Some women with low iron experience restless legs, poor sleep quality, or difficulty feeling rested despite adequate sleep duration. #### What is ferritin and why is it important? Ferritin measures your stored iron reserves. It can become depleted before anemia develops, making it an important marker when evaluating unexplained fatigue. #### Can low iron feel like perimenopause? Absolutely. Fatigue, brain fog, anxiety, poor sleep, reduced exercise tolerance, and mood changes can occur with both low iron and perimenopause, which is why evaluating both is often important. ## Your health won’t wait—why should you? Let’s get to the root of what’s getting you stuck. Schedule Your Discovery Call Today Get actionable tips delivered to your inbox so you can start using right away to feel more energized and improve your overall health. Get It Here References: 1. Auerbach M, DeLoughery TG, Tirnauer JS. Iron Deficiency in Adults: A Review. JAMA. 2025;333(5):421-432. doi:10.1001/jama.2024.27574 2. Voelker R. What Is Iron Deficiency? JAMA. 2025;333(5):405. doi:10.1001/jama.2024.28604 3. Firquet A, Kirschner W, Bitzer J. Forty to Fifty-Five-Year-Old Women and Iron Deficiency: Clinical Considerations and Quality of Life. Gynecol Endocrinol. 2017;33(7):503-509. doi:10.1080/09513590.2017.1284780 4. Luo J, Wang X, Yuan L, Guo L. Iron Deficiency, a Risk Factor of Thyroid Disorders in Reproductive-Age and Pregnant Women: A Systematic Review and Meta-Analysis. Front Endocrinol (Lausanne). 2021;12:629831. doi:10.3389/fendo.2021.629831 5. Camaschella C. Iron-Deficiency Anemia. N Engl J Med. 2015;372(19):1832-1843. doi:10.1056/NEJMra1401038 6. da Silva Lopes K, Yamaji N, Rahman MO, et al. Nutrition-Specific Interventions for Preventing and Controlling Anaemia Throughout the Life Cycle: An Overview of Systematic Reviews. Cochrane Database Syst Rev. 2021;9(9):CD013092. doi:10.1002/14651858.CD013092.pub2 5. Hurrell R, Egli I. Iron Absorption: Factors, Limitations, and Improvement Methods. Nutrients. 2024;16(2):245. doi:10.3390/nu16020245 Disclaimer: This information is for educational purposes only and is not intended as medical advice. Consult a qualified healthcare professional before making any health-related decisions. Individual results may vary.