Dr Ahmed, a UK-based GP with more than 280,000 followers on TikTok, has revealed a common deficiency that could be the reason behind your constant tiredness.

He explained: "Are you tired all the time? You've tried everything, nothing's working, all your tests have come back normal? But wait, before you give up, this is one mineral that's probably low even if it comes back normal in your blood test that you'll benefit from if you try."

He explained why this mineral, magnesium, is often overlooked: "This is often low in many people and can cause ongoing fatigue. And that mineral is magnesium. Even if you've done the magnesium blood test and it came back normal, that isn't very accurate and I'll explain why."

Dr Ahmed clarified the issue with standard testing methods: "Only 1% of magnesium is in your blood. The vast majority of it is intracellular inside your cells. So even if your magnesium blood level is within the normal range you can still be deficient in it.

"The only way to accurately measure your magnesium levels is by doing a 24 hour urine collection and because of the cumbersome nature of doing this it is very rarely done."

Dr Ahmed also highlighted the critical role of magnesium in supporting over 300 enzyme systems within the body, which includes its involvement in protein synthesis, muscle and nerve function, blood pressure regulation, and glucose management.

He elaborated: "Hence, if you're deficient you may well be feeling tired. Because of over-farming, chronic diseases and medication the prevalence of magnesium deficiency is vast across the human population."

The doctor concluded with a suggestion for those constantly fatigued despite normal test results, proposing a trial of magnesium supplements to potentially enhance energy levels. Understanding the various forms of magnesium is essential for maintaining health, and Dr Ahmed provided insights into each type and their benefits.

Magnesium citrate, as Dr Ahmed notes, "is the most well-absorbed out of all the supplements. However, be careful because it can cause diarrhoea. So therefore if you're constipated it's good and some studies show it can help with migraines too".

Magnesium glycinate is beneficial for sleep and mood issues, according to Dr Ahmed, who explained: "Glycine is both an amino acid and neurotransmitter, therefore this supplement particularly helps with poor sleep and low mood."

Regarding magnesium L-threonate, Dr Ahmed said: "This is the only supplement that crosses the blood-brain barrier. Therefore it really helps with cognition and memory."

He also discussed magnesium taurate. "This one is very interesting because studies have shown it can help with blood pressure control and sugar management, however more studies are needed," he said. "If you've got high blood pressure or are diabetic, this could be a good one to try."

And finally, regarding magnesium sulfate, he said: "This is a great one for those who can't take tablets. It's also known as Epsom salt. You put them in your bath and you can actually absorb the magnesium through your skin."