According to a pharmacist, people taking some prescription medications may be unaware that they are risking vitamin and mineral deficiencies as a side effect. Peter Thnoia said certain medicine combinations can reduce the level of vitamins and minerals in the body.
48% of Brits struggle to get the correct amount of vitamins and minerals in their daily diet, according to a study by the Nutraceutical Business Review, and the medications we rely on daily may also be exacerbating the problem.
“It’s not just about what we eat - many patients are unknowingly at risk of nutrient deficiencies because of the medications they rely on daily,” said Peter Thnoia, Superintendent Pharmacist at PillTime. “This can affect energy levels, immune function, and long-term wellbeing.
“Of course, this doesn’t mean patients should stop taking their medications. But it does mean that there needs to be more education about the impact certain medications have on your body’s ability to absorb nutrients, so that patients are informed about additional steps that they may need to take to improve their general health and wellbeing.”
Brits are notoriously deficient in Vitamin D, but Peter warns that lots of common prescription medications may also limit the absorption of other important vitamins and minerals from UK diets – and the long-term health impacts could be lifechanging.
1. Thyroid medications, such as levothyroxine, impacts vitamin B absorption – causing nerve issues
Currently, around 1.36 million people in England take Levothyroxine for an underactive thyroid, a common hormone condition linked to the butterfly shaped gland in the neck.
“People taking thyroid medications like levothyroxine often don’t realise these treatments can affect how their body processes essential nutrients, such as B vitamins, due to how the body breaks down the medication. These vitamins play a key role in energy and brain function.
“Prolonged vitamin B deficiency can have a significant impact on your health, including decreased cognitive function, fatigue and nerve issues. So, it’s important to keep an eye on levels, consider supplements and speak to your GP if you notice changes in how you feel.”
2. High blood pressure medications, such as diuretics, can cause low potassium levels – and cause muscle weakness
“Diuretics, often prescribed for high blood pressure or heart conditions, help the body remove excess fluid — but they can also flush out important minerals like potassium.
“Low potassium can lead to muscle weakness, cramps, fatigue, and even heart rhythm disturbances if left unchecked.
“Whilst eating a diet of potassium-rich foods like bananas, avocados and sweet potatoes will help to combat some of the lost levels, anyone taking diuretics should have their nutrient levels monitored regularly, as this can make a real difference in spotting early signs.”
3. Arthritis and asthma medication can cause calcium deficiency – and increase risk of bone disorders
“Corticosteroids are widely used to manage chronic conditions like asthma, rheumatoid arthritis, lupus, and inflammatory bowel disease — and while they’re highly effective at reducing inflammation, long-term use can reduce calcium absorption and increase calcium excretion. This puts patients at a higher risk of weakened bones, osteoporosis, and fractures, especially as they age.
“If you’re taking corticosteroids regularly, it’s important to monitor your bone health and consider calcium and vitamin D supplementation where appropriate. With the right support, you can manage both your condition and your nutritional wellbeing.”
4. Diabetes medications such as SGLT2 inhibitors prevent vitamin B absorption – and can cause memory issues
“With diabetes medications like SGLT2 inhibitors, people understandably focus on managing their blood sugar - but these drugs can also impact how your body absorbs and utilises key nutrients.
“In particular, we often see reduced absorption of water-soluble vitamins like B1 (thiamine) and B12, which are vital for nerve health, energy metabolism, and cognitive function.
“Over time, low levels can contribute to fatigue, memory issues, or even worsening diabetic neuropathy. That’s why regular medication reviews - and being aware of how your treatment affects your wider health - are so important.”
5. Blood pressure medication, such as Statins, can deplete coenzyme Q10 levels - and lead to heart problems
“Statins are commonly prescribed to lower cholesterol and reduce the risk of heart disease - but many people don’t realise that, over time, they can also reduce levels of coenzyme Q10, a nutrient that plays a key role in energy production within our cells.
“Low CoQ10 levels may contribute to muscle aches, fatigue, and even reduced heart function in some individuals. It’s something that needs to be watched closely, especially in patients who report tiredness or muscle discomfort. Pharmacist-led support can help identify these issues early and explore options like supplementation if needed.”
