Nutrient deficiencies are very common in those suffering from fatigue.
There are many reasons for this, ranging from soil depletion, malabsorption, medications, genetics and food quality.
Magnesium is one such example. Involved in hundreds of biochemical reactions, magnesium is fundamental for energy production.
Many in the population are deficient.
A deficiency in magnesium can negatively impact the energy pathways your mitochondria use to generate adenosine triphosphate (ATP), the energy currency of our cells.
This results in fatigue, low grade inflammation and free radical damage.
How can one assess their status? My approach is to test and not guess.
The red blood cell test is a reliable way of measuring levels.
In rare cases, an excess in specific nutrients can actually contribute to fatigue.
The answer? Balance.
With the correct testing and personalisation, these deficiencies can be corrected, occasionally leading to rapid symptom improvement.
Types of deficiencies
Other commonly overlooked deficiencies that may contribute to fatigue include iron, vitamin D, B12, and CoQ10.
Each of these plays a vital role in cellular energy production, oxygen transport, and nervous system regulation. For example, low iron can lead to reduced oxygen delivery to tissues, while inadequate B12 can impair nerve function and cognitive clarity—often mistaken for mental fatigue. Even mild deficiencies can have a cumulative impact on how we feel day to day.
That’s why a thorough nutritional assessment, ideally guided by a healthcare practitioner, is so valuable. Functional testing can help uncover root causes that standard blood tests may miss, especially when levels fall within the “normal” range but are still suboptimal for energy and performance.
Supplementation should always be strategic—more isn’t always better, and indiscriminate use of high-dose nutrients can sometimes do more harm than good.
With the right data and a tailored approach, however, correcting deficiencies can be a game changer.
For many, it represents one of the lowest-hanging fruits in the journey to overcoming fatigue and reclaiming vitality.
You can find other ME/CFS related blogs here.
Shaun Moran