7 Nutrient Deficiencies That May Lead to Low Energy—And the Best Foods for Bringing Your Battery Back to Life

Photo: Getty Images/Daniel de la Hoz
It may be normalized to complain of low energy, but chronically low energy levels are certainly not normal and there may be a nutrient deficiency causing fatigue. While specific nutrient deficiencies are associated with low energy, you’ll want to consider whether or not you are taking in enough energy—literally, from calories—first.

As logical as it sounds, many people make the mistake of jumping into the world of micronutrient deficiencies before considering whether or not they have been in a calorie deficit for an extended period of time. Even if your calorie deficit has been unintentional, it can be affecting your energy levels in a big way. Some simple questions to consider first are whether or not you eat three square meals, regular snacks, and drink plenty of water every day. These are the bare minimum requirements to make sure that you are nourished and not in a calorie deficit.

Experts In This Article

Let’s quickly take a look at what makes up a well-rounded day of nourishing foods before we jump into nutrients of concern. You’ll want to take a look at the three major macronutrients—protein, carbs, and fat—in your diet in addition to calories to make sure that you’re eating enough. Here’s what dietitians have to say about fueling for energy levels:

  • Calories: “The number-one deficiency causing low energy is calories,” says Mandy Tyler, RD, CSSD, LD. “Underfueling, or not consuming adequate daily calories to support health and daily activity, results in an energy deficiency that can impact an individual’s health. Inadequate calorie intake can contribute to other nutrient deficiencies, worsening low energy.”
  • Carbs: Carbohydrates are your body's favorite source of energy to use. When you don't eat enough carbohydrate foods throughout the day, you can feel like you're dragging. It's no surprise that many people who try to follow a "low carb" diet often feel exhausted, adds Jamie Nadeau, RD, of The Balanced Nutritionist.
  • Protein: Low protein intake can cause fatigue and low energy levels. Protein-based foods provide the body with fuel to repair and build tissues. Protein takes longer than carbohydrates to break down in the body, providing a longer-lasting energy source, Moushumi Mukherjee, RDN, tells us.
  • Fats: Feeling sluggish could mean you’re skimping out on your dietary fat. Of the three macronutrients, fat is the most energy-dense, providing 9 calories per gram. Research shows that omega-3 fatty acids can improve cognitive function and performance by aiding blood circulation in the brain, helping to keep you awake and energized, says Madeleine Putzi, RD.
  • Hydration: Low intake of water can really impact energy levels. Even a body water loss of one to two percent causes fatigue. If you need to up your fluid intake, focus on including beverages that are unsweetened and non-caffeinated, a variety of fruits and vegetables (which can make up to 20 percent of your fluid needs), and soups, offers Maxine Yeung, RD, dietitian and owner of The Wellness Whisk.

Now that we’ve got those big dial movers covered, let’s get in to specific nutrient deficiencies causing fatigue that could be contributing to low energy and exactly which foods dietitians recommend you eat to help bring your nutrition up to speed.

Vitamin C

Vitamin C is also known as an antioxidant that can help with everything from wound healing to boosting the immune system—and increasing your energy levels. The recommended daily intake for vitamin C is 75 mg per day for women and 90 mg per day for men. Lots of fruits and veggies come with this built in energy booster including berries, oranges, broccoli, and kiwi.

Vitamin C helps produce energy, contributes to normal energy yielding metabolism, and helps with the reduction of fatigue, says Lauren Manaker, RDN, LD. “One source of vitamin C is Zespri SunGold Kiwis, offering more than 100 percent of your daily needs per serving. These kiwis with a smooth, hairless skin, sweet and refreshing taste, and juicy, yellow flesh are all you need to meet your vitamin c needs,” she adds.

Vitamin D

Vitamin D is a fat-soluble vitamin that is a precursor to nearly all hormones in the body. Thus, vitamin D has been associated with fluctuations in energy and fatigue as it relates to hormonal and brain health. Vitamin D is unique in that you can only find it in select foods like egg yolks, salmon from Alaska, and milk. If your vitamin D levels are low enough, your doctor may prescribe a high-dose supplement in order to bring your levels up to speed.

Vitamin D deficiency can be associated with fatigue in individuals with certain conditions such as multiple sclerosis (MS), rheumatoid arthritis (RA), cancer, and lupus, shares Lisa Andrews, RD, LD. Sources of vitamin D include casual sun exposure, milk, eggs, and vitamin D-fortified foods like cereals.

Vitamin B12

If you eat very little animal-based foods, take regular medication for acid reflux, or have a digestive disorder such as Crohn’s, and you’re experiencing new fatigue, there’s a chance you could be deficient in Vitamin B12, offers Tori Vasko, RD, CNSC.

Vitamin B12 plays a unique role in boosting energy levels and specifically, cognitive function. Folks with vitamin B12 deficiency often complain of fatigue, memory issues, and weakness. For people who are plant-based, vitamin B12 is a nutrient of concern for deficiency risk, and you may need supplementation if your nutrition plan hasn’t been thoughtfully curated. If vitamin B12 deficiency is significant, you may be at risk for pernicious anemia.

“Vitamin B12 is found in animal-based foods such as fish, meat, poultry, eggs, and dairy products. Since plants do not naturally contain vitamin B12, vegetarians and vegans need to pay special attention to their intake. Fortified breakfast cereals and nutritional yeasts are good plant-based sources of highly bioavailable vitamin B12,” recommends Melissa Boufounos, CHN, sports nutritionist and owner of MB Performance Nutrition.


Though technically a mineral and not a vitamin, iron deficiency is a major culprit for low energy levels. Heme iron is the most bioavailable form, which means that it can be digested and absorbed the easiest in our diet. We get heme iron from animal-based foods like red meat, fish, and poultry.

Iron deficiency is the first go-to nutrient to check for low energy, especially for women and teen girls, according to Sarah Pflugradt, RDN, CSCS. “Your body needs iron to make red blood cells and red blood cells carry oxygen,” she says. “Low iron can leave you feeling like you have no energy or less energy than you usually have. Good sources of iron are animal proteins, such as beef, poultry, and fish—and also plant proteins such as beans, lentils, and fortified cereals and grains. Pair your iron-rich foods with a source of vitamin C like strawberries, orange juice, bell peppers, or kiwi to help your body better absorb the iron.”


Omega-3 fatty acids are uniquely linked to good energy levels in addition to heart health, joint health, and brain health. In the U.S., most people do not consume a healthy ratio of omega-3 fatty acids compared to omega 6 fatty acids. Omega-3s can be found in wild caught, Alaskan salmon, walnuts, chia seeds, and flaxseeds.

Omega-3 deficiency is linked to overall fatigue, allergy symptoms, muscular cramping, and difficulty paying attention and staying alert,” says Kristen White, RDN. “Good food sources of omega-3 are wild caught salmon, sardines, flaxseeds and flaxseed oil, and walnuts.”


Drinking enough water and taking in the right amount of electrolytes can significantly help improve energy levels. Some people who may need extra electrolytes include athletes, people who work in hot, humid conditions, breast-feeding moms, or folks who just sweat a lot.

Electrolytes are actually a group of minerals—sodium, potassium, phosphorus, magnesium—that help move water from our bloodstream into our cells where it can be used for all of our hydration and fluid needs. Electrolyte deficiency can be incredibly dangerous as it influences blood pressure, heart rate, and energy levels.

“Fatigue and low energy could be a sign that you're dehydrated. For maximum hydration, look for drinks with electrolytes, like bone broth. Bone broth is packed with calcium, potassium, sodium, and magnesium to replenish electrolyte stores that are low when we’re dehydrated,” says Bianca Tamburello, RDN.


Magnesium is an electrolyte, but it has a variety of influences on energy levels outside of it’s role in hydration. “Low levels of magnesium can contribute to fatigue and low energy levels,” says Wan Na Chun, MPH, RD, CPT, of One Pot Wellness. “Muscle weakness, cramps, and spasms are also common symptoms of magnesium deficiency, further impacting energy levels.”

Leafy green vegetables, nuts, seeds, whole grains, and legumes are excellent dietary sources of magnesium, she adds. Safe magnesium dosing is up to the recommended intake of 350 milligrams per day.

comments on another way magnesium deficiency impacts our energy levels: sleep!

“Additionally, magnesium supports the body's natural melatonin development in promoting sleep and may be more effective than melatonin supplementation alone,” says Andrew Akhaphong, RD, LD, registered dietitian for Mackenthun's Fine Foods. “Folks at risk for magnesium deficiency include having a poor diet or allergies to the major food sources like nuts and seeds, gastrointestinal disorders like Crohn's disease and celiac, kidney disease, and long-term diuretic use.”

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