Key Takeaways
B vitamins, vitamin D, magnesium, and iron play important roles in energy metabolism, oxygen transport, and muscle function, so low levels may lead to low energy.
Supporting your body's nutritional foundation helps maintain normal energy production processes. Key nutrients work together as cofactors to help your cells unlock energy from the food you eat.
A balanced diet is the foundation of adequate nutrient intake, but lab testing and appropriate supplementation may help fill nutrient gaps.
When you're struggling with low energy, pinning down the cause can be difficult. There are many potential factors, but diet often plays a part. While macronutrients like carbohydrates and protein contain the "fuel" for energy production, micronutrients (vitamins and minerals) play a key role as cofactors and signaling molecules to turn that fuel into energy.
And yet, vitamin inadequacies are still possible, even among otherwise healthy people. Fortunately, there are adjustments you can make to start getting your energy back. Let's take a closer look at what vitamin inadequacies cause low energy and how to correct them.
Energy production is like a complex biological relay race. Nutrients from food are broken down, converted into more usable forms, and passed along to the next phase. Eventually, these raw materials reach the mitochondria—cellular power plants—and are turned into ATP, the body's energy currency.
Vitamins and minerals play a crucial role in this process. For example, without sufficient thiamine (B1), mitochondria can't effectively use glucose for fuel. Magnesium binds to and stabilizes ATP and is required for hundreds of reactions that use or generate cellular energy. Oxygen is also essential for energy production. To reach our cells, oxygen is carried through the bloodstream by hemoglobin in red blood cells, which relies on iron.When key micronutrients are insufficient, the machinery of energy production may not function optimally, which can contribute to tiredness, 'heavy' or weak limbs, and difficulty focusing.
So, what vitamin inadequacy causes low energy? While there isn't any one nutrient shortage that causes tiredness, these are the most important:
The eight B vitamins are water-soluble and have to be replenished daily. They work together, meaning an inadequacy in one often impairs the functioning of another. B vitamins are crucial cofactors in ATP production, neurotransmitter synthesis (serotonin, dopamine), red blood cell formation, and maintaining the protective sheath for nerves.4 Low levels can lead to difficulty concentrating, mood changes, fatigue, and sleep disturbances.
We can get vitamin D from sunlight, though it can also be found in fortified foods such as milk, breakfast cereals, orange juice, and yogurt. Vitamin D supports muscle function, immune health, and low levels have been associated with fatigue in some studies.5 Emerging research suggests vitamin D may support serotonin regulation, which can influence mood.6
As a key enzyme cofactor, magnesium is crucial to every process that uses or transfers ATP. It also helps stabilize ATP. Low magnesium can make minor physical tasks feel difficult.
When nutrients are limited, tissues with high energy demands—like muscles and the parts of the brain involved in focus—are often the first places people notice symptoms. Signs that you may have insufficient nutrient intake include:
If you feel you should have more energy than you do, try following these guidelines for boosting energy levels, beginning with a well-rounded diet of whole foods to ensure adequate nutrient intake.
Fatigue can have many causes, and it's important to speak with your doctor if you have concerns about your energy levels.
The only way to know for sure if it's a vitamin inadequacy that makes you tired is to see your doctor. They will often recommend lab tests that tell you how much of key nutrients are in your system. You can then work out a plan for addressing shortfalls.
Vitamin inadequacies and low energy are often linked, but sluggishness can signal many different health conditions. These symptoms may indicate conditions requiring medical evaluation beyond nutritional support.
There's no substitute for a nutrient-rich diet of whole foods. However, when life gets busy, it can be difficult to track nutrient intake consistently.
If you're proactively looking to support your daily nutrient intake, AG1 delivers more than 75 vitamins, minerals, and whole-food-sourced ingredients—including B-complex and magnesium—that help fill common nutrient gaps.* If you're experiencing signs of low vitamin D levels, such as low energy and achiness, we offer vitamin D as a separate liquid for enhanced absorption. Try AG1 today.
* AG1 doesn't contain significant amounts of iron.
Vitamin inadequacies and low energy are seen even in developed countries. According to the National Health and Nutrition Examination Surveys (NHANES), approximately 96% of people are consuming inadequate amounts of vitamin D, 6% inadequate iron, and 13% vitamin B6.3
Iron is critical for the hemoglobin in red blood cells that carry oxygen through the bloodstream, as well as myoglobin, which stores oxygen in muscles.7 It's also the most common nutrient inadequacy worldwide.8 This can affect physical stamina and cognition.
For a deeper dive, read our guide to the key vitamins and minerals for energy.