Feeling unusually tired, out of breath or struggling to think clearly could signal hidden nutrient deficiencies, which may quietly affect energy, focus and overall health
Vitamin deficiencies can leave you struggling with everyday tasks (Stock Photo) (Image: Getty Images)
Symptoms like constant tiredness, experiencing mental fuzziness, and occasional tingling in the hands and feet are often brushed off as stress or ageing. But these symptoms can be warning signs of nutrient deficiencies, including vitamin B12, iron, and folate (B9), which play really important roles in brain function, nerve health, and oxygen delivery.
These symptoms can be red flags from your body and recognising them early is important, as deficiencies can quietly affect nerve health, oxygen delivery, and overall energy, leaving you struggling with everyday tasks. Around 15 per cent of those aged 15 to 29, and 20 per cent of over-60s, will have levels of the vitamin that may not fall into the range of a deficiency, but are low enough to cause symptoms, the Daily Mail reports.
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An iron deficiency can also lead to tiredness and fatigue (Stock Photo)(Image: Getty)Vitamin B12
Vitamin B12 helps the brain send signals efficiently and keeps nerves protected. Low levels can cause memory problems and balance issues, which in older adults may increase the risk of falls. Some people may have borderline B12 levels that don’t qualify as a full deficiency but can still trigger these symptoms.
Certain groups are more vulnerable. Vegans are at risk since B12 is mainly found in animal-based foods such as milk, beef, eggs, and fish. Older adults can struggle to absorb B12 efficiently due to reduced stomach acid. Long-term use of acid-reducing medications like proton pump inhibitors can also limit absorption, potentially requiring supplements or injections.
Iron
Iron is vital for producing haemoglobin, the protein in red blood cells responsible for transporting oxygen. When iron is low, oxygen delivery suffers, and high-energy tissues such as the brain and nerves feel the effects first, causing light-headedness and cold hands.
Iron works alongside folate and B12 to produce red blood cells. Deficiencies in any of these nutrients reduce the body’s ability to transport oxygen, making everyday tasks like climbing stairs or staying warm feel more exhausting. In the UK, iron deficiency affects roughly 3 per cent of men and 8 per cent of women.
Folate
Folate supports cell growth and red blood cell production. Levels have declined steadily over recent years, with teenagers showing the highest rates of deficiency. Women of childbearing age are especially vulnerable: insufficient folate can increase the risk of neural tube defects in early pregnancy.
To combat this, the UK government plans to fortify white flour with folic acid by the end of 2026, targeting bread and baked goods. Folate can also be obtained from leafy greens, beans and citrus fruits.
Blood tests are the most reliable way to confirm a deficiency. Iron is difficult to restore through diet alone, as absorption is tightly controlled, so supplements are often required, particularly for those with heavy periods or gut issues. Folate deficiencies are generally easier to correct with dietary changes or supplementation.
For those who need to boost their B12, this can look different depending on the method. Vegans may need supplements, while older adults or those on long-term acid-suppressing medications might require higher doses or injections.
Ignoring deficiencies can allow symptoms to persist and may cause permanent nerve damage, but there is good news. Once deficiencies are spotted and tackled, most people notice improvements within weeks. For many energy levels, mental clarity, and overall well-being can recover quickly, making a real difference in daily life.
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