Signs of 7 Common Nutritional Deficiencies (and How to Fix Them Naturally)

Nutritional Deficiencies


Having low levels of certain key nutrients can compromise your brain function, disturb your mood, impact your energy levels, and affect your overall well-being. The following 7 nutrients are commonly below what’s considered to be “adequate intake” in many people and correcting them could make a marked difference in how you think, feel, and operate in the world.


Adequate magnesium helps to calm anxious feelings and stress, and this essential mineral is also known to balance the pleasure centers of the brain, which can help decrease cravings. Click To Tweet


1. Vitamin B12: Fatigue, shortness of breath, headaches, impaired brain function

It’s all too common for Americans to have inadequate levels of a number of B complex vitamins, including vitamin B12 (cobalamin). Vitamin B12 is found in sufficient amounts only in animal foods (excepting certain seaweeds). Hence, 80–90% of vegetarians and vegans may be deficient in vitamin B12, research indicates. Additionally, more than 20% of older adults may have low levels of this vitamin as absorption decreases with age, studies have found.

Low B12 can lead to what is called vitamin B12 deficiency anemia, a condition characterized by lower levels of red blood cells, which are essential for carrying oxygen throughout your body. This can cause fatigue, paleness, shortness of breath, headaches, or dizziness. Other symptoms include impaired brain and nervous system function, as well as elevated homocysteine levels – a risk factor for heart disease, dementia, and stroke.

Optimize your nutrient levels naturally: You can boost your vitamin B12 levels by eating shellfish (clams and oysters), organ meats (liver), meat, eggs, and milk products.

2. Vitamin B9: Poor cognitive function, memory problems, depression

Better known as folic acid or folate, vitamin B9 tends to run low in young women of childbearing age and non-Hispanic black women, research shows. Folate deficiency increases the risk of neural tube defects, making it very important for pregnant women.

Adequate amounts of folic acid is needed for healthy nervous system function at all ages, research shows. Low levels of folic acid can negatively affect cognitive function (memory, understanding, and judgment), especially in older people. Deficiency is associated with depression and dementia. Low folate, like low B12, can lead to anemia too.

Optimize your nutrient levels naturally: Increase your folate by consuming fortified cereals, beans, peanuts, sunflower seeds, whole grains, eggs, and dark leafy greens.

3. Vitamin B6: Mood changes, fatigue, tingling

Also known as pyridoxine, vitamin B6 is a cofactor for about 150 reactions that regulate the metabolism of sugars, fats, proteins, DNA, and neurotransmitters – including serotonin, GABA, epinephrine, and norepinephrine – making it really important for healthy brain and nervous system function.

A Tufts University study found inadequate vitamin B6 levels common among women of reproductive age – especially those who use or have used oral contraceptives. Low vitamin B6 is usually associated with low concentrations of other B-complex vitamins, such as vitamin B12 and folic acid, research has found.

Vitamin B6 is needed for the production of hemoglobin, the compound in red blood cells that transports oxygen and carbon dioxide, and helps increase the amount of oxygen carried in your blood, which helps reduce fatigue. It helps maintain a healthy immune system and calms anxiety.

Signs of low B6 include mood changes, fatigue, weak immunity, skin rashes, cracked and sore lips, a sore, glossy tongue, high homocysteine levels, seizures, and tingling or pain in the hands and feet.

Optimize your nutrient levels naturally: Increase vitamin B6 levels by consuming skinless roasted turkey breast, fish, beef liver and other organ meats, potatoes, and other starchy vegetables, and bananas (other than citrus).

4. Vitamin D: Low moods, memory problems, muscle weakness

Vitamin D is essential for brain health, mood, memory, immune, and skin health. Remarkably, vitamin D receptors are present in nearly every tissue and cell in the body.

Known as the “sunshine” vitamin, vitamin D is synthesized in the skin with exposure to sunlight. Low levels are prevalent among Americans. The National Institutes of Health estimates about 42% of people in the U.S. may be deficient in vitamin D. A National Health and Nutrition Examination Survey estimates 94.3% of the U.S. population does not even meet the daily requirement for vitamin D.

Low levels of vitamin D are, in part, due to Americans spending more time indoors and wearing sunscreen outdoors. Deficiency is higher in the winter months when there’s less available light in the Northern Hemisphere. Also, dietary sources of vitamin D are quite limited.

Vitamin D activates receptors on neurons in areas that are critical to the regulation of behavior, and it serves to protect the brain with its antioxidant and anti-inflammatory properties. Suboptimal levels of vitamin D are associated with depression, bipolar disorder, and memory problems, including Alzheimer’s disease.

Vitamin D is also essential for ensuring normal calcium absorption and maintenance of healthy calcium levels in the body. Signs of vitamin D deficiency may include muscle weakness, bone loss, and an increased risk of fractures. Children may experience growth delays and soft bones. Low vitamin D may also compromise immune function and increase the risk of cancer, research shows.

Optimize your nutrient levels naturally: The richest food sources of vitamin D are cod liver oil, fatty fish, and egg yolks. Supplementation is likely required, and it is wise to consult your medical doctor to determine how much you need to take.

5. Magnesium: Stress, anxiousness, irritability, muscle weakness

Magnesium is needed for more than 300 biochemical reactions in the body. It is truly essential to good health, yet research shows around 70% of the U.S. population under 71, and roughly 80% over 71 years old, don’t consume enough. Low levels of magnesium, over time, are associated with a number of health issues, including high blood pressure, atherosclerosis, cardiac arrhythmias, as well as stroke, blood sugar problems, changes in lipid metabolism, and metabolic syndrome, according to research.

Magnesium plays a significant role in your brain health, mood, energy, and nervous system. Lack of magnesium is linked to depression and neuropsychiatric conditions. Research shows adequate magnesium helps to calm anxious feelings and stress, and this essential mineral is also known to balance the pleasure centers of the brain, which can help decrease cravings, research suggests.

Magnesium also plays a vital role in energy production and aids in the uptake of calcium and potassium. Irritability and nervousness can result from low levels of magnesium. Taking a magnesium supplement can sometimes help to boost mood and improve muscle weakness. One study found that when combined with vitamin B6, magnesium has been shown to calm hyperactivity in children with ADHD.

In addition to diet-restricted magnesium deficiency, deficiency may be caused by disease, drug use, or poor digestive function, according to research. Studies point to a number of common symptoms with severe magnesium deficiency including abnormal heart rhythm, muscle cramps, restless leg syndrome, fatigue, and migraines. Deficiency is also associated with nausea and loss of appetite.

Optimize your nutrient levels naturally: Ensure ample magnesium intake by consuming whole grains, nuts, dark chocolate, and dark green leafy vegetables. 

6. Iron: Fatigue, weakness, impaired brain function

Iron deficiency is the world’s most common nutritional deficiency, affecting roughly 10 million people in the U.S., according to one estimate – and most often young children, menstruating women, and pregnant women. What is considered low iron is currently being debated, but as much as 30% of both women and children in the U.S. may be considered iron-deficient under new thresholds being considered, research says.

A 2021 Journal of Nutrition study documented a drop in iron levels in both men (6.6%) and women (9.5%) in the U.S. from 1999 to 2018 attributed to dietary shifts such as less consumption of red meat.

Iron is a major component of red blood cells, where it binds with hemoglobin and does the important task of bringing oxygen to your cells. Our bodies obtain iron from our diet, and there are two forms: Heme iron and non-heme iron. Heme iron comes from animal sources, especially red meat. It is very well absorbed. Non-heme iron is found in both animal and plant foods and is not absorbed as well as heme iron.

Vegetarians are more likely to be iron deficient than non-vegetarians, research has found, likely because they consume mostly non-heme iron.

Low levels of iron frequently lead to anemia, which is when your red blood cell levels and your blood’s ability to carry oxygen decrease. Typical symptoms include fatigue, weakness, compromised immune response, and impaired brain function.

Iron is critical to brain development and cognitive function. Some research has found that too little or too much iron in the blood can disrupt healthy nervous system function leading to memory problems and attention and behavioral issues – all associated with brain fog.

This vital mineral is involved in many fundamental processes in the brain including, of course, oxygen transportation, but also with DNA, myelin, and neurotransmitter synthesis. It’s also required for mitochondrial respiration and neurotransmitter metabolism.

Low iron is associated with anxiety, depressive symptoms, and other psychiatric disorders, as well as sleep disorders, according to research.

Optimize your nutrient levels naturally: Increase your intake of heme iron by eating lean red meat, fish, and poultry. Or consume rich sources of non-heme iron such as beans, dark chocolate, lentils, spinach, potato with skin, nuts, and seeds, or enriched bread, rice, or breakfast cereals.

7. Calcium: Stress, anxiousness, negative moods, brain fog

Calcium mineralizes bones and teeth – especially during growth spurts, and plays a crucial role in bone maintenance. It is also essential for every cell in your body and is a signalizing molecule as well. Without calcium, your nerves, muscles, and heart would not function.

Your body expertly regulates calcium, storing any excess in bones. If you are lacking in calcium intake, it will draw on this stored calcium. Osteoporosis, characterized by softer and more fragile bones, is the most common symptom of calcium deficiency.

The National Health and Nutrition Examination Survey found that 44.1% of the U.S. population (age 4 and up) do not meet the daily requirement for calcium, and flagged the low consumption as a health concern.

In addition to playing a critical role in bone health, calcium signals control blood flow in the brain. Healthy blood flow is necessary for every area of brain health. It helps to regulate several neuronal functions, including neurotransmitter synthesis and release, and neuronal excitability. Calcium also plays a role in long-term processes, such as memory.

Lower calcium intake is associated with higher perceived stress and higher levels of negative mental health states, such as anxiety and negative mood, according to a 2022 study.

Fatigue, body aches, low mood, poor oral health, muscle pain and spasms, brain fog, dizziness, cognitive issues, abnormal heart rhythm, tingling or numbness, and even seizures can be symptomatic of low calcium.

Optimize your nutrient levels naturally: In addition to consuming dairy products, eat salmon, sardines (with bones), kale, collards, broccoli, bok choy, almonds, and sesame seeds to boost your calcium levels.


The Linus Pauling Institute reports that nutrient deficiencies are largely due to poor intake of nutrient-rich fruits, vegetables, whole grains, and dairy. Your brain and overall well-being depend on getting adequate nutrients, so feed your brain and body the foods you need. Or consider nutritional supplements to help optimize your levels.

Nutritional deficiencies are related to many mental health issues that can’t wait. At Amen Clinics, we’re here for you. We offer in-clinic brain scanning and appointments, as well as mental telehealth, clinical evaluations, and therapy for adults, teens, children, and couples. Find out more by speaking to a specialist today at 888-288-9834 or visit our contact page here.


  1. How refreshing to read critical health information that is not buried in an advertisement. I will be adding more nuts, red meat, and fish to my grocery list. Thank you!

    Comment by Peggy Parker — May 24, 2023 @ 4:18 AM

  2. Thank you for this nutritional information at a glance. I AM a Healthcare provider and this information is beneficial for me to pass on to my patients.

    Comment by Kim — May 24, 2023 @ 4:26 AM

  3. I so appreciate the knowledge shared by Amen clinics, so this is in no way directed at Amen–I was just compelled to write how frustrated I am with the fact that I am not a big eater. I don't have a bad relationship with food, it's more "meh"….so I eat to sustain much more than for pleasure. I have a pretty empty relationship with eating, and sometimes it stresses me out, because I am likely not consuming enough daily overall and the diversity of my diet is questionable.

    Comment by Delilah Loesch — May 24, 2023 @ 6:18 AM

  4. Do you have supplements that will help these deficiencies?

    Comment by Karen Barefield — May 24, 2023 @ 8:33 AM

  5. Thanks for keeping us on our toes to be aware of nutritional facts!

    Comment by Virginia Bean — May 25, 2023 @ 4:57 PM

  6. Folic acid? You must mean folinic acid not folic acid, correct? Folic acid can make a folate deficiency worse. Eating foods fortified with folic acid will decrease absorption of folate. What we need is folinic acid or folate.

    Comment by Trina — May 27, 2023 @ 12:32 PM

  7. excellent advice!

    Comment by Douglas Morris — May 30, 2023 @ 6:04 PM

  8. For more information about Dr. Daniel Amen's recommended, brain-directed supplements, visit

    Comment by Amen Clinics — June 2, 2023 @ 10:35 AM

  9. I agree with Kim (above) . I love passing along information to help my clients.

    Comment by Janice Jackson — June 4, 2023 @ 8:11 AM

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