Nutrient deficiencies that cause fatigue

3 Nutrient Deficiencies To Rule Out If You’re Always Feeling Tired

Dr. Kimberley O'BrienBlog, Health Leave a Comment

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As a naturopathic doctor, I help you to identify and address the underlying cause of any symptoms you may be experiencing. If you’re looking to experience more energy, our first step is always to identify WHY you’re tired in the first place! When we gain clarity as to the cause of your low energy, we also gain a roadmap of how to fix the problem so that you can feel like your fabulous self again!

If your energy is low and you’re often feeling sluggish, nutrient deficiencies may be one of the imbalances that are causing your fatigue. Ensuring that you consume a diet rich in vitamins and minerals is very important to maintain the health of your body. There are a few nutrients that play very important roles specifically in regards to energy production, and I often screen for these nutrient deficiencies in my patients who are experiencing fatigue.  

Common Nutrient Deficiencies That Cause Fatigue


Iron is a mineral that is essential for your body to produce red blood cells and to transport oxygen throughout your body via hemoglobin. Iron is also required for muscle function, since it’s a critical component of a protein called myoglobin. When your body doesn’t have enough hemoglobin and myoglobin due to iron deficiency, less oxygen reaches your tissues and muscles, depriving them of energy!  This can cause fatigue, along with possible shortness of breath, heart palpitations, restless legs and dizziness. Adequate iron is also required to produce energy within each of your cells, as well as for thyroid hormone and neurotransmitter production. All in all, iron is a very important mineral for you to have in adequate reserves in order to feel energized!

Women are at greater risk of iron deficiency because of the loss of iron through menstruation.  Those with heavy periods are most likely to experience low iron levels due to increased blood loss. Vegan or vegetarian diets also increase the likelihood that you may experience low iron levels, as well as if you experience malabsorption, low stomach acid or other digestive concerns.

Nutrient Deficiencies Fatigue

Iron is best assessed via a blood test for ferritin, which is your body’s stored form of iron.  If you experience fatigue, it’s likely that your medical doctor may have already run this test for you.  However, it’s very important to note that conventional “normal” levels are too low and that you typically aren’t notified of your low iron status unless your ferritin is less than 15 ug/L.  Optimal levels should be at least 50 ug/L, or ideally in the range of 80-100 ug/L. Therefore, make sure to check your lab reports to confirm that you’re reaching optimal levels before ruling out an iron-deficiency as the cause of your low energy!


Of eight total different B-vitamins, those most important to energy production include Vitamin B5, B6, B9 and B12.  All of these B-vitamins play a role in the breakdown of fats, proteins and carbohydrates for energy, as well as in the production of red blood cells.  Some of the B-Vitamins, including vitamin B5, are also involved in the production of sex, stress and energy-related hormones produced in the adrenal glands.

B-vitamins are water soluble, which means they don’t easily accumulate within your body and the excess is excreted in your urine. Although easy excretion decreases your likelihood of developing toxic levels of these nutrients, it also means that your body does not have the same ability to build reserves of B-vitamins and other water-soluble nutrients. Lower reserves means that nutrient levels are easier to be depleted, especially as compared to fat-soluble vitamins.  Many drugs are also known to deplete B-vitamins levels, including birth control pills (oral contraceptives), antihypertensives (drugs for elevated blood pressure), proton pump inhibitors (drugs for gastrointestinal reflux) and oral hypoglycemics (drugs for diabetes).

While a deficiency of any of the B-vitamins can negatively affect your health and lead to low energy, it’s vitamin B12 that I test patients for most often in my practice. This is because vitamin B12 can be difficult for the body to absorb from food, requiring that your body is producing enough stomach acid, as well as a protein called “intrinsic factor”, to transport it across the gastrointestinal barrier.  

Nutrient Deficiencies Fatigue

If you are taking a proton-pump inhibitor or any other acid-blocking medications, it’s more likely that you’ll experience low vitamin B12 levels, as well as other nutrient deficiencies, due to the suppression of your stomach acid.  If you experience reflux or other digestive upset, identifying whether your symptoms are caused by particular foods can enable you to treat the root cause and to avoid the need to suppress your stomach acid production through medications.

As with iron, the conventional normal range for vitamin B12 is much too broad and the lower end of the “normal” range is far from ideal.  Make sure to check your lab reports and ensure that your vitamin B12 level is at least 450 pmol/l for optimal health and energy.

Nutrients That Are Required For Thyroid Hormone Production, Including: Iodine, Selenium and Zinc

Thyroid hormones establish your metabolic rate and directly influence your level of energy. If your thyroid hormone production is not optimal, in addition to fatigue you might also experience additional symptoms like constipation, bloating, hair loss and weight gain.  

Thyroid hormone production requires several steps, and it’s critical that you have adequate amounts of certain nutrients for this process to occur effectively.  Of the many nutrients involved, iodine, selenium and zinc are three of those that are most important.

Nutrient Deficiencies Fatigue

Selenium and zinc are minerals that are very important for thyroid hormone production, as well as for immune health.  Selenium can also be very helpful in cases of Hashimoto’s thyroiditis, and it’s been studied to help lower the autoimmune reactivity that is the number one cause of low thyroid function in North America.  Brazil nuts are a fabulous source of selenium, with only 3-6 brazil nuts per day enabling you to reach a therapeutic daily dose of approximately 200mcg of selenium. Nuts, seeds, meat, shellfish and legumes are good sources of zinc. 

Iodine is one of the primary nutrients required as a building block for your body to produce thyroid hormones.  Iodine is found primarily in sea vegetables, like kelp or nori, as well as fish, shrimp and other seafood. Dairy products also contain iodine, however dairy is a very common food sensitivity that can cause bloating, fatigue and constipation in susceptible individuals (which can easily be confused with the symptoms of hypothyroidism!).  If you experience these symptoms I highly recommend that you assess whether certain foods may also be causing inflammation for you, so you can best fuel your body for health and energy!


It’s important to work with a naturopathic doctor or other qualified health professional who’s well versed in thyroid health BEFORE you start taking supplements to try and boost thyroid function.  Why? You want to make sure these nutrients are safely indicated for you before taking them in high dose. For example, taking iodine can be detrimental to your thyroid function if you have Hashimoto’s thyroiditis, which is the most common cause of hypothyroidism. Therefore, it’s important to rule out Hashimoto’s before looking to improve thyroid function with the supplementation of iodine.

Although nutrient deficiencies like iodine, selenium and zinc can be diagnosed through private laboratories, these assessments typically are not available conventionally.  Working with naturopathic doctor can help you to personalize your diet, identify any nutrient deficiencies and maximize your health and energy!

Identify The Cause of Your Fatigue, So You Can Fix it and Feel fabulous!

Nutrient deficiencies are one of the 5 most common causes of fatigue that I diagnose for my patients in my naturopathic practice.  I’ve put together a free guide for you called “Fatigued to Fabulous”, which covers all 5 of these causes in further detail and also includes a quiz to help you identify what may be at the root of your own low energy.  I invite you to download “Fatigued to Fabulous” for free here!

If you’re feeling sluggish and tired, incorporating more nutrient dense foods into your diet can be one of the most effective ways to improve your health and boost your energy! 

What are your biggest challenges or struggles when it comes to healthy eating? Let me know in the comments below!

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Nutrient Deficiencies that Commonly Cause Fatigue

About the Author

Dr. Kimberley O'Brien


Dr. Kimberley O'Brien is a Naturopathic Doctor in  Nelson, BC with expertise in the treatment of digestive disorders, fatigue and hormone imbalances.  She is the founder of Healthy Life Redesign and creator of the Elimination Diet Meal Plan and the Real Food Recharge online programs.  Her mission is to help you own your health and live a life you love!

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