Posted on August 14, 2026

by Jillian Levy

Expertly reviewed by Brian Tanzer, Nutritionist, Dir. of Scientific & Regulatory Affairs

Feeling mentally exhausted, unmotivated, or like you’re running on empty? It’s tempting to assume that burnout—a combination of physical, mental, and emotional exhaustion brought on by stress—is to blame. But this run-down state isn’t the only explanation for symptoms like fatigue, brain fog, poor concentration, and low mood. There are several nutrient deficiencies that can mimic burnout.

Because chronic stress, poor sleep, and skipped meals are all common among people who are actually “burnt out,” low levels of nutrients and exhaustion can sometimes go hand in hand. “Many nutrients can be involved in burnout-type symptoms, including the B vitamins, vitamin D, choline, magnesium, manganese, iron, and omega-3s,” says Rebecca Fallihee, L.D.N., owner of Gutsy Performance Nutrition. 

Below, we’ll cover some of the most common nutrient deficiencies that are worth discussing with your healthcare provider if you’re feeling chronically drained.

• ABOUT OUR EXPERTS: Rebecca Fallihee, L.D.N., is a board-certified clinical nutritionist and owner of Gutsy Performance Nutrition. Bonnie Taub-Dix, M.A., R.D.N., C.D.N., is a registered dietitian and creator of BetterThanDieting.com.

1. B Vitamins: The Energy-Supporting Nutrients

B vitamins—including B1, B2, B3, B5, B6, B9 (folate), and B12—are needed to convert food into energy and support healthy brain function and nervous system regulation. These are among the key nutrients involved in energy production and cognitive function, says Fallihee. “When levels become too low, people may notice fatigue, difficulty focusing, brain fog, or memory problems,” she adds. Other signs you might be lacking B vitamins can include:

• Weakness when exercising

• Poor recovery

• Irritability

• Low mood

“Vitamin B12 deficiency is especially common among older adults, people following vegan diets, and those with digestive conditions that impair absorption,” says Bonnie Taub-Dix, M.A., R.D.N., C.D.N.

Taub-Dix adds that each B vitamin has its own job, and many work together. For that reason, healthcare providers often recommend a B-complex supplement rather than a single B vitamin when deficiencies are suspected.

2. Iron: When Low Energy Isn’t Just Stress

If you feel physically exhausted even after a full night’s sleep, it could be due to iron deficiency. This is one of the most common nutrient deficiencies worldwide and a leading cause of fatigue, particularly among women of childbearing age.

Read More: 6 Signs You’re Not Getting Enough Iron

“Iron helps red blood cells carry oxygen throughout the body, so without enough, tissues and muscles receive less oxygen, leaving you feeling tired and mentally sluggish,” says Taub-Dix. In addition to fatigue, iron deficiency symptoms can include:

• Difficulty concentrating

• Headaches

• Weakness

• Shortness of breath during activity

• Pale skin

Because too much iron can cause side effects like constipation, supplementation should usually be started only after a healthcare provider confirms a deficiency, explains Taub-Dix.

3. Magnesium: Nature’s Stress-Relieving Mineral

Magnesium is an electrolyte—one that has a lot to offer for your energy levels. According to Taub-Dix, “magnesium participates in hundreds of biochemical reactions throughout the body, including muscle function, nerve signaling, sleep regulation, and energy production.” Low magnesium can be a cause of issues such as:

• Fatigue

• Muscle tension

• Poor sleep

• Anxiety

• Difficulty concentrating

Because chronic stress can increase magnesium losses in some cases, low intake and burnout can wind up reinforcing one another.

Other types of electrolyte imbalances (including low levels of sodium, potassium, and calcium) as well as dehydration can sometimes trigger fatigue, too. “So many people walk around lightheaded, irritable, and exhausted without realizing they may be dehydrated or lacking essential electrolytes,” says Taub-Dix. Electrolytes help regulate fluid balance, muscle contractions, nerve signaling, blood pressure, and brain function. Therefore, dizziness, muscle cramps, weakness, or brain fog can all signal an electrolyte imbalance. 

According to Taub-Dix, preventing electrolyte imbalances starts with staying hydrated, especially if you’re exercising, spending time in hot weather, or losing fluids from vomiting or diarrhea. “In some situations, water alone may not be enough,” she says. “An electrolyte beverage, coconut water, or a sugar-free sports drink may help replace what’s been lost.”

4. Vitamin D: More Than a Bone Nutrient

Vitamin D is well known for supporting bone health, but it’s also involved in immune function and defense against illnesses, as well as muscle health, brain function, and mood regulation. Low vitamin D levels are associated with higher risk for fatigue, low mood, and even reduced motivation—all symptoms you might experience with burnout.

Because we get most of our natural vitamin D from sun exposure, people who spend little time outdoors, live in northern climates, or have darker skin tones are at higher risk for deficiency. (Notably, if you’re burnt out from a desk job, you might not be spending much time outside.)

A blood test can determine whether supplementation is appropriate and how much might be helpful. For the general population, about 2000 IU/day (50 mcg/day) of vitamin D3 can help prevent deficiency. 

5. Protein: The Steady Energy Macronutrient

Not every energy slump points to a vitamin or mineral (micronutrient) deficiency. Sometimes, you’re missing a certain macronutrient, such as protein. 

Protein supplies the amino acids your body needs to build muscles, produce enzymes and hormones, and make neurotransmitters involved in mood and cognitive function. Consistently falling short can leave you feeling fatigued, mentally sluggish, and less able to recover from physical or mental stress.

Choosing foods that combine protein with other nutrients can help support steadier energy and cognitive function. “Protein-rich foods like fish, eggs, Greek yogurt, cheese, or a handful of nuts can provide lasting energy, help stabilize blood sugar levels, and keep you feeling satisfied longer,” says Taub-Dix.

She also notes that exhaustion itself can make healthy eating more difficult. “Being too tired can lead to apathy and poor food choices,” she says. “Keeping protein-rich snacks handy gives you better options when your energy is low.”

Read More: How Much Protein Do You Really Need?

6. Omega-3 Fatty Acids: Brain Support From Healthy Fats

Fun fact: The human brain is the fattiest organ in the body. Omega-3 fats, particularly EPA and DHA, are concentrated in the brain and help support healthy brain function and communication between nerve cells. In certain populations, low omega-3 intake has been linked to symptoms such as difficulty concentrating, brain fog, low mood, and mental fatigue.

The Dietary Guidelines for Americans recommend eating two to three servings of fish per week, partly to boost omega-3 intake. People who rarely eat fatty fish like salmon, sardines, trout, or mackerel may benefit from discussing an omega-3 supplement with their healthcare provider, says Taub-Dix.

7. Choline: An Often-Overlooked Brain Nutrient

Choline doesn’t receive as much attention as many other nutrients, but it’s essential for producing acetylcholine, a neurotransmitter involved in learning, memory, and attention. Low choline intake may contribute to tiredness, brain fog, memory problems, and difficulty focusing. These may sound familiar if you’re in the throes of burnout.

Eggs, beef, fish, soy foods, and poultry are among the richest dietary sources. Or talk to your doctor about adding choline via a supplement.

Could It Be More Than a Nutrient Deficiency?

According to Fallihee, burnout symptoms tend to be multifaceted. “Nutrient deficiencies may be one contributing factor, but it’s important to look at the bigger picture,” she says. So while a nutrition-rich diet is important, it’s often only one piece of the puzzle if you’re frequently feeling exhausted.

Some possibilities? Burnout-like symptoms can also stem from chronic stress, inadequate sleep, blood sugar imbalances, hormone changes, thyroid disorders, inflammation, or other underlying health conditions, say Fallihee and Taub-Dix. Excess inflammation and impaired detoxification can also contribute, says Fallihee. And, of course, there may be overlap between these issues and nutrient deficiencies.

Can Supplements Help?

If testing confirms a deficiency, or your healthcare provider suspects one, supplementation can likely help restore healthy nutrient levels. “Once someone is quite depleted, temporary or long-term supplementation may also be needed to restore vitamin and mineral levels, and those needs can be very personal,” says Fallihee. Additionally, she points out that “it’s rarely just one vitamin or mineral that’s missing. Several nutrient deficiencies can contribute to similar symptoms, which is why it’s important to evaluate overall nutrition rather than assuming there’s a single cause.”

Just remember that supplements aren’t meant to replace a nutritious diet. “A balanced diet with adequate whole grains, diverse fruits and vegetables, and varied lean proteins—both plant and animal, if not vegetarian—will support many individuals in preventing deficiencies,” says Fallihee. 

Bottom Line 

Burnout and nutrient deficiencies can share many of the same symptoms, including fatigue, brain fog, poor concentration, memory problems, and low mood. In some cases, the two may even occur together, especially during periods of prolonged stress.

If you’re feeling persistently exhausted despite getting enough rest, don’t assume it’s “just burnout.” A conversation with your healthcare provider—and, when appropriate, lab testing—can help determine whether an underlying nutrient deficiency or another health condition may be contributing.