Does your tank still feel empty even after a full night's sleep? It might be time to pay closer attention to what's on your plate — or rather, what's missing.
While there are many possible causes for fatigue, dietary deficiencies are a common culprit, says William W. Li, MD, author of Eat to Beat Disease. Indeed, vitamins and minerals are involved in metabolism, oxygen transport and neuronal functions, so an insufficient supply can lead to side effects such as sleepiness, per a January 2020 paper in Nutrients.
Here, Dr. Li shares which nutrients you need (and what foods to eat) to keep your energy levels up.
If you’re constantly tired, it’s best to consult with your medical provider who can properly assess the underlying cause of your fatigue and design an appropriate treatment plan.
1. Vitamin B12
"Vitamin B12 is used by the body for building red blood cells, which carry oxygen to our other cells," Dr. Li says. So, when your diet lacks enough B12, your healthy red blood cells become compromised.
This results in less oxygen traveling to your tissues, which is why you feel tired, Dr. Li explains.
Clams, salmon, yogurt, eggs and beef liver are good sources of vitamin B12 as well as fortified foods like certain cereals, Dr. Li says.
Is Your Diet Missing Certain Nutrients?
"Zinc is critical for a healthy metabolism, so deficiencies in this micronutrient often results in fatigue," Dr. Li says.
Indeed, zinc is essential for regulating adenosine triphosphate (ATP), which is the source of energy at the cellular level, per a 2017 paper in Einstein (Sao Paolo). The same article notes that taking zinc supplements helped prevent exhaustion in people undergoing chemotherapy.
"Healthy foods containing zinc include shellfish like oysters and mussels, beans, lentils and chickpeas," Dr. Li says.
Magnesium is necessary for energy production, building strong bones and muscle health, so a deficiency in this mighty mineral can lead to tired muscles and weakness, Dr. Li says.
Magnesium also plays an important role in the cardiovascular system as well as other biological processes such as blood sugar regulation and protein synthesis, according to the National Institutes of Health.
"Healthy foods containing magnesium include pumpkin seeds, cashews, almonds, swiss chard, spinach, okra and soybeans," Dr. Li says.
4. Vitamin D
Vitamin D is used by the body for building strong bones and supporting a healthy immune system, Dr. Li says. Consequently, when your body has a dearth of vitamin D, you're likely to feel lethargic.
In fact, people with low vitamin D levels who received a dietary supplement for five weeks experienced a significant improvement in their fatigue symptoms, per an August 2014 study in the North American Journal of Medical Sciences.
"Foods containing vitamin D include mushrooms, salmon, mackerel, sardines and fortified foods like milk and cereals," Dr. Li says.
Iron deficiency is the most common form of anemia, a condition in which the body lacks ample healthy red blood cells, according to the U.S. National Library of Medicine.
Here's why iron is important: It's used to create hemoglobin, the chemical that makes your blood red and carries oxygen throughout the body, Dr. Li says. Without enough oxygenated blood to nourish your cells and tissues, you're bound to feel weak. In other words, low oxygen equals low energy.
Healthy foods with iron include spinach, peas, lentils, chickpeas, beans, tofu, sardines, oysters, clams and mussels, Dr. Li says.
6. Vitamin C
While immune-supportive vitamin C helps protect against oxidative stress, this vital nutrient is also utilized by the body for making collagen, which is critical for our bones and joints, Dr. Li says. Plus, vitamin C is essential for creating amino acids used for building healthy muscles, he adds.
Thus, when your body doesn't get enough vitamin C to bolster your bones, joints and muscles, you tend to feel tired.
"Foods containing vitamin C include citrus fruits, tomatoes, red bell peppers, guava, kiwi, broccoli and Brussels sprouts," Dr. Li says.
- Nutrients: “Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence”
- Einstein (Sao Paolo): " Effects of zinc supplementation on fatigue and quality of life in patients with colorectal cancer"
- National Institutes of Health: “Magnesium”
- North American Journal of Medical Sciences: “Correction of Low Vitamin D Improves Fatigue: Effect of Correction of Low Vitamin D in Fatigue Study (EViDiF Study)”
- U.S. National Library of Medicine: “Iron deficiency anemia”