Feeling tired occasionally is a normal part of life. Feeling tired constantly, despite adequate sleep, is something else entirely. One in eight people reports feeling fatigued all the time, and nearly three in five women say they wake up exhausted even after a full night of sleep. For many, the explanation turns out to be a nutritional deficiency or lifestyle factor that responds well to treatment once it is identified.
Fatigue without an obvious cause is one of the most common reasons people visit their doctor. The difficulty is that it has many possible origins — poor diet, chronic stress, digestive dysfunction and micronutrient deficiencies can all produce the same overwhelming sense of depletion. Identifying the specific cause is essential to finding a real solution.
Iron deficiency is the most common starting point
Low iron is the most widespread nutritional deficiency in the world and is particularly common in women. Symptoms extend beyond tiredness and can include shortness of breath, heart palpitations, difficulty concentrating, dizziness and hair thinning. Iron is essential to haemoglobin, the protein in red blood cells responsible for transporting oxygen to the brain and muscles. When iron stores fall low enough, the body simply cannot generate enough energy to function properly.
Women are disproportionately affected because of monthly blood loss during menstruation, and those following plant-based diets face additional risk because the iron found in vegetables and pulses is absorbed significantly less efficiently than the iron from red meat. A blood test measuring ferritin and haemoglobin levels is the standard first step in diagnosis. If deficiency is confirmed, prescribed iron tablets are the typical treatment, taken every other day with vitamin C to enhance absorption. Building red blood cell stores back up takes roughly three months, though improvement in how a person feels can come sooner.
Identifying the underlying cause of the deficiency matters as much as treating it. Certain intestinal conditions can cause gradual blood loss or impair nutrient absorption, and both should be investigated if iron levels remain persistently low despite supplementation.
Lifestyle factors that drain energy
The gut plays a central role in how much energy the body can produce, because it governs how efficiently nutrients are absorbed. A diet heavy in processed foods and refined carbohydrates promotes gut inflammation, which disrupts that absorption process and leaves the body operating on less than it needs. Shifting toward a nutrient-dense diet built around vegetables, fruit, quality proteins and healthy fats is one of the most effective long-term adjustments a person can make.
Alcohol and chronic stress are two additional drains that are frequently underestimated. Alcohol depletes B vitamins needed for energy metabolism, disrupts sleep quality and acts as a physiological depressant. Chronic stress taxes the adrenal system and depletes key micronutrients including vitamin C, magnesium and B vitamins — all of which are required for healthy energy production. Regular physical exercise is one of the most effective antidotes to stress-related fatigue, as it stimulates endorphin production, improves circulation and supports the cellular processes underlying energy generation.
Supplements that may help
Several nutrients and compounds have meaningful evidence behind them for addressing fatigue. Vitamin D deficiency is widespread, particularly in regions with limited sunlight, and supplementing year-round supports energy levels, immune function and bone health. Vitamin B12 is critical for energy metabolism and is most reliably obtained through animal products, while folate supports red blood cell production and is well sourced from leafy greens, pulses and fortified grains. Vitamin C paired with magnesium supports cellular energy production and helps manage the inflammatory burden in the gut. Calcium, while also connected to energy, carries risks if taken without medical guidance and is better assessed through a blood test before supplementing.
Among herbal and specialty supplements, ashwagandha has shown promise as an adaptogen that helps regulate the body’s stress response and reduce fatigue, with one 2021 study finding measurable benefit at doses between 120 and 1000 mg daily. Creatine supports the energy systems used in muscle function and has emerging research linking irregularities in creatine metabolism to post-viral fatigue. Coenzyme Q10 and L-carnitine are both involved in how the body converts nutrients into usable energy, and L-arginine combined with vitamin C showed improved physical performance and reduced fatigue in a 2022 study of long Covid patients.
Any supplementation is best guided by blood test results and, where possible, a conversation with a medical professional before beginning a new regimen.
