Should You Really Be Taking That Supplement?

With supplements stacked high on health store shelves and wellness trends flying around Instagram, it’s tempting to think we should all be taking a long list of pills and powders “just in case.” But here’s the truth: supplements aren’t inert. 

They’re powerful tools—when used correctly.

But when taken blindly or mixed with medications without thought, they can do far more harm than good.

I am always asked about supplements, and I have had long training and years of clinical experience with them. I’m also a midlife woman who takes targeted supplements. So, I know a fair bit about how to choose supplements wisely, and what you need to know before reaching for the latest trend.

Supplements Aren’t Always Helpful—and Can Be Harmful If Misused

If your body doesn’t need a nutrient, taking more won’t boost your health. In fact:

• You might just waste your money (especially with water-soluble vitamins like B and C, which are excreted if unneeded)

• You might store toxic levels (with fat-soluble vitamins like A and D) which can become very harmful

• You could disrupt delicate nutrient balances, and even interfere with medications

  
  

More isn’t better. Smarter is better.

Fat-Soluble vs Water-Soluble Vitamins—Why This Matters

• Fat-soluble vitamins (A, D, E, and K) are stored in your liver and fat tissues, meaning they build up over time. Vitamin A toxicity is well documented, and taking high-dose vitamin D without vitamin K may lead to calcium being deposited in the arteries instead of the bones.

• Water-soluble vitamins (B-complex and C) are generally flushed out when in excess—but that doesn’t mean they’re harmless. For example, long-term high doses of B6 can lead to nerve issues that can be irreversible.

• B12, while water-soluble, is stored in the liver—so deficiencies can take years to appear, and symptoms can be masked until quite severe.

  
  

 Supplements + Medications: A Combo That Can Be Risky

When you're on medications, adding supplements without proper guidance isn't just unhelpful—it can be dangerous.

Supplements That Can Interfere With Medications

Some supplements increase or block the effects of medications, altering how they work—sometimes significantly.

• Fish oil & vitamin E: Can increase bleeding risk when taken with blood thinners like warfarin or newer anticoagulants (e.g. apixaban, rivaroxaban).

• St John’s Wort: Can speed up drug metabolism, reducing the effectiveness of medications such as:

  • Antidepressants

  • The pill

  • Blood thinners

  • HIV antivirals

• Calcium & magnesium: Can interfere with absorption of thyroid medications (like levothyroxine) and some antibiotics.

• Iron: Can reduce effectiveness of Parkinson’s medications and certain antibiotics.

• Vitamin K: Can counteract warfarin, disrupting its blood-thinning effect.

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These interactions are real and can be dangerous—especially when combined with multiple medications or over-the-counter supplements.

When Medications Deplete Nutrients

Some medications cause nutrient deficiencies by using up your body’s stores as they’re metabolised. Often, the “side effects” you feel are actually signs of underlying depletion.

• Statins (cholesterol meds): Deplete CoQ10, essential for energy. Low levels may cause fatigue, brain fog, muscle aches.

• PPIs (e.g. omeprazole): Reduce stomach acid and therefore impair the absorption of:

  • Vitamin B12 – leading to fatigue, tingling, mood changes

  • Magnesium – linked to anxiety, cramps, poor sleep

  • Iron and calcium – essential for blood and bone health

• Metformin (type 2 diabetes): Lowers B12, increasing the risk of nerve damage and anaemia.

• The contraceptive pill: Depletes B vitamins (B6, B12, folate), magnesium, and zinc.

• Diuretics: Can flush out potassium, magnesium, and zinc, which are critical for energy, mood, and heart rhythm.

  
  

These depletions often go unnoticed until they start causing symptoms—and many of them can be reversed or managed with targeted nutrition.

Nutrients Don’t Work in Isolation—And Sometimes They Compete

Taking a high dose of one nutrient can unintentionally block or deplete another. A few common examples:

• Too much zinc can cause copper deficiency, leading to anaemia or weakened immunity.

• Calcium and iron compete for absorption, and when taken together, both can be poorly absorbed.

• High-dose vitamin D should be taken with vitamin K2 to help direct calcium to bones instead of arteries.

• B vitamins work best in synergy. Taking one (like B6 or B3) on its own long-term can cause imbalances unless there’s a specific deficiency identified and a short-term dose is being used under GP or practitioner guidance.

  
  

This is another reason why it’s vital to get your levels checked before taking individual nutrients long-term.

Use Your Bloods! Your Body Is Telling You What It Needs

Even a basic Full Blood Count (FBC) and a few extra markers can provide valuable insight:

• High MCV (mean cell volume)? You may be low in B12 or folate.

• Low neutrophils or lymphocytes? Possibly zinc or immune-related deficiencies.

• Raised CRP or other inflammatory markers? Time to support with omega-3s, antioxidants, gut or detox work.

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These results help us tailor your supplements to what your body actually needs, saving you money and avoiding potential harm.

Functional Testing: Going Deeper

Want to understand energy, detox, gut health, or inflammation on a deeper level? I use advanced tools like Organic Acid Testing (OAT) to assess:

• B-vitamin function

• Mitochondrial health (energy)

• Oxidative stress

• Microbial overgrowth

Combined with blood tests, we can pinpoint exactly where your support should go.

Modern Diets & Stress Burn Through Nutrients Fast

Even if you eat well, today’s food is less nutrient-dense than it once was—thanks to soil depletion, food processing, and long storage.

Add in the fast pace of life, blood sugar swings, stimulants and poor sleep, and you're burning through B vitamins, magnesium, and vitamin C faster than you can replace them.

Worse still, ultra-processed foods and refined carbs don’t just lack nutrients—they act as anti-nutrients, drawing on your mineral stores to be metabolised.

Work With a Qualified Nutritional Therapist

This is where I come in. I use your bloods (and advanced testing where needed) to figure out what’s actually going on in your body. That means:

• No more guessing

• No wasting money on unneeded supplements

• Safer interactions with your medications

• Targeted, effective support for your energy, mood, and long-term health

  
  

Book your Wellness Check with me today

Let’s get clear on what your body needs—and what it doesn’t.

Not sure if you want a longer programme or if Nutritional Therapy would suit you at all? Book a free 20 minute Health Review with no pressure at all to work with me.

Free Health Review

Book a free 20-minute ‘Reboot Your Health’ call today, and let’s create a personalized plan to get you feeling your best!