Read This Before You Start Taking Supplements
Walk into any health food shop or scroll through wellness posts online, and you’ll find shelves (and feeds) overflowing with supplements that promise better energy, glowing skin, sharper focus and stronger immunity. It’s tempting to believe a capsule can fill in all the gaps. But before you add a cocktail of tablets to your morning routine, it’s worth pausing.
Taking supplements without knowing your body’s needs can be more harmful than helpful.
Why blood testing comes first
The first step in any supplement journey should be blood testing. Nutrient levels vary widely between individuals, influenced by diet, lifestyle, health conditions, and even genetics. A blood test can identify whether you are deficient—or whether your levels are already adequate.
For example, vitamin D deficiency is common in the UK due to limited sunlight exposure, especially in winter. A test can confirm whether supplementation is necessary. On the other hand, many people have perfectly sufficient levels of certain nutrients (such as B12, folate, or iron), and supplementing unnecessarily can lead to unwanted side effects.
When supplements do more harm than good
Taking supplements when you don’t need them isn’t a neutral choice. In some cases, excess intake can disrupt your body’s balance:
Iron: Too much iron can cause gastrointestinal distress, liver damage and increase oxidative stress.
Vitamin A: High doses can be toxic, leading to headaches, dizziness, nausea and, over time, bone loss or liver problems.
Vitamin D: Essential for bone health and immune function, but excessive intake can cause dangerously high calcium levels, leading to kidney damage.
Zinc: While important for immunity, too much zinc can interfere with copper absorption and weaken immune responses.
Supplements are not inherently safe just because they are sold over the counter.
What your body really needs from essential vitamins
Each vitamin plays a specific role in maintaining health. More is not better—balance is.
Vitamin A: Vision, skin health, immune function.
Vitamin C: Collagen production, wound healing, antioxidant defence.
Vitamin D: Calcium absorption, bone health, immune regulation.
Vitamin E: Protects cell membranes from oxidative stress.
Vitamin K: Blood clotting and bone metabolism.
B vitamins (B1, B2, B6, B12, folate, niacin, pantothenic acid, biotin): Energy metabolism, nerve function, red blood cell formation.
These vitamins often work synergistically with minerals and other nutrients found in food. When levels are adequate, “topping up” with high-dose supplements provides no added benefit—and in some cases, risks toxicity.
Why what works for your friend may not work for you
It’s common to hear success stories: “Magnesium cured my anxiety” or “Vitamin B12 gave me energy.” While these anecdotes are genuine, they may not apply to you. If your friend had a deficiency, supplementation would understandably make them feel better. But if your levels are normal, taking the same supplement won’t have the same effect—and could tip the scales in the wrong direction.
Human biology is individual. Genetics, gut health, diet, lifestyle and existing medical conditions all shape how nutrients are absorbed and used. This is why personalised health advice—backed by testing—is always more reliable than copying someone else’s regimen.
The bottom line
Supplements can be powerful tools, but only when used appropriately. Instead of self-prescribing based on trends, advertising or anecdotes:
Start with a blood test to know your baseline.
Consult a healthcare professional to interpret the results.
Prioritise food first—a balanced diet remains the best source of nutrients.
Use supplements to correct deficiencies, not to chase quick fixes.
Your body is a finely tuned system. More isn’t always better—and when it comes to supplements, sometimes less is safer.
If you would like to speak to a medical profession regarding anything mentioned in this article, please email our team at team@thewellnesslondon.com.