Three key nutrients for energy production

Mitochondria—the energy factories inside our cells—play a crucial role in physical and mental stamina. For people living with conditions like ME/CFS or Long Covid, where energy production is impaired, supporting mitochondrial function can be key to symptom management.

Here we describe three key nutrients for energy that can support mitochondrial health and potentially help with fatigue: Carnitine, Iron, and CoQ10.

1.  Carnitine - the fatty acid transporter

What it does - Carnitine helps shuttle fatty acids into the mitochondria where they are converted into energy. It also removes waste products from this process. Though the body can produce it naturally (mainly in the liver and kidneys), certain health conditions may increase demand beyond what we can make. The body needs 15mg of carnitine daily from what it produces and from food sources.

Sources of carnitine

• Animal foods  such as beef, pork, cod, chicken and dairy foods are the richest sources

• Vegan diets may provide as little as 1.2 mg/day compared to 24–145 mg/day from omnivorous diets

Best food sources of carnitine

Carnitine In ME/CFS:

Research (Reuter 2011) has shown that carnitine levels are 30–40% lower in people with CFS compared to healthy controls and that lower levels correlate with worse fatigue.

Another study (Plioplys, 1997) found that L-carnitine supplementation significantly improved symptoms over 4–8 weeks. Combining omega-3 fatty acids with L-carnitine may further improve energy metabolism.

2. Iron – not just for anaemia

Iron is essential for enzymes involved in making ATP—the energy molecule. Deficiency, even without anaemia, can impair muscle function, cause fatigue, and contribute to conditions like restless leg syndrome, fibromyalgia, and sleep disorders.

Types of iron in food and its absorption

• Haem iron: found in meat; absorbed more efficiently (14–18%)

• Non-haem iron: from plants; less absorbed (5–12%)

• Vitamin C (peppers, kiwi, citrus fruit broccoli) boosts absorption of iron

• Phytates in beans and grains can inhibit absorption of iron from food

How much iron do we need ?

Details of our daily requirements for iron are shown below. Before menopause women need more iron daily due to blood loss from menstruation. Men and women who are vegan need to have about twice as much iron as those who eat animal foods as non-haem iron is less bioavailable.

3.  Coenzyme Q10 (CoQ10) - the cellular spark plug!

What it does - CoQ10 supports ATP production and protects cells as an antioxidant. It’s especially important for energy-hungry organs like the heart, liver, and brain. Natural levels decline with age and can be depleted by chronic illness and oxidative stress, statin use or vitamin B6 deficiency

Research on CoQ10 In ME/CFS:

A study by Maes and colleagues in 2009 showed that nearly half of ME/CFS patients had lower CoQ10 levels than any of the healthy controls. Lower CoQ10 was linked to worse memory and concentration.

In another study (Castro-Marrero, 2021), supplementing with 200mg of CoQ10 and  20mg of NADH led to reduced fatigue, better sleep, and improved quality of life in a 12-week trial.

Research on CoQ10 in Long COVID:

A prospective observational study( Barletta, 2023) found that those who received CoQ10 + alpha-lipoic acid had significantly lower fatigue scores than untreated participants, with 53% of patients benefiting from this treatment.

Food sources of CoQ10

Taking Supplements

Before starting any supplements, always consult your healthcare provider—especially if you take medications.

Supplementing with L-Carnitine

• Forms - L-carnitine or acetyl-L-carnitine (better for brain support)

• Dose - 500–2000 mg

• Side effects - Mild digestive discomfort, rare body odour

• Drug interactions -  Can affect warfarin, levothyroxine, and blood thinners

Supplementing with CoQ10:

• Forms -  Ubiquinone or ubiquinol (active form)

• Dose -  90–200 mg daily

• Must be taken with food, it is a fat soluble molecule

• Drug interactions - may alter effectiveness of blood thinners, chemo drugs, and anti-hypertensives

Final Thoughts

Supporting mitochondrial health through nutrition can make a meaningful difference for those living with fatigue-related conditions. Nutrients like carnitine, iron, and CoQ10 play important roles in cellular energy production and can be targeted through diet—and in some cases, supplements—for improved well-being.

References

Reuter SE, Evans AM. Long-chain acylcarnitine deficiency in patients with chronic fatigue syndrome. Potential involvement of altered carnitine palmitoyltransferase-I activity. J Intern Med. 2011 Jul;270(1):76-84. doi: 10.1111/j.1365-2796.2010.02341.x. Epub 2011 Jan 19. PMID: 21205027.

Plioplys AV, Plioplys S. Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome. Neuropsychobiology. 1997;35(1):16-23. doi: 10.1159/000119325. PMID: 9018019.

Maes M, et al. Coenzyme Q10 deficiency in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is related to fatigue, autonomic and neurocognitive symptoms and is another risk factor explaining the early mortality in ME/CFS due to cardiovascular disorder. Neuro Endocrinol Lett. 2009;30(4):470-6. PMID: 20010505.

Castro-Marrero, J. et al. Effect of Dietary Coenzyme Q10 Plus NADH Supplementation on Fatigue Perception and Health-Related Quality of Life in Individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Prospective, Randomized, Double-Blind, Placebo-Controlled Trial. Nutrients 2021, 13, 2658. https://doi.org/10.3390/nu13082658

Barletta MA, et al. Coenzyme Q10 + alpha lipoic acid for chronic COVID syndrome. Clin Exp Med. 2023 Jul;23(3):667-678. doi: 10.1007/s10238-022-00871-8. Epub 2022 Aug 22. PMID: 35994177; PMCID: PMC