The rise of functional laboratory testing has led to an explosion of expensive tests promising to uncover physiological and nutritional imbalances linked to health issues. These tests claim to provide deep insights into gut health, nutrient deficiencies, food sensitivities, and metabolic imbalances, allowing practitioners to create highly personalised and targeted nutrition and lifestyle recommendations.
To test or not to test - that is a fairly common topic of discussion and based on clinical experience, the answer is often NO. The mantra "test, don’t guess" is widely used in the field, but relying on functional testing as a starting point rarely changes initial recommendations. Instead, I believe that laying a strong foundation with core health habits is what we need to focus on. If symptoms persist despite these adjustments, then testing becomes a valuable next step.
That being said, there are two exceptions in my practice: Vitamin D testing and Metabolic Balance blood tests—both of which I’ll explain in more detail.
But first, let’s explore the essential health foundations I encourage clients to focus on before considering advanced testing. In most cases, symptoms such as digestive discomfort, hormone imbalances, fatigue, and skin issues can be significantly improved through these simple yet powerful changes.
Foundational Health Habits to Prioritise First
Balance blood sugar – Eat regular, nutrient-dense meals that include proteins, healthy fats, whole grains and vegetables to stabilise energy levels, reduce insulin spikes, and prevent cravings.
Increase fibre intake – Support gut, immune, and nervous system health by increasing plant diversity. Try fermented foods and introduce at least one new vegetable, or (real) food item into your diet each week.
Manage stress – Even the best diet won’t help if your body is in a constant stress response. Incorporate relaxation practices like mindfulness, breathwork, meditation, singing & dancing, or simply having fun to support digestion and hormone balance.
Prioritise quality sleep – A consistent bedtime routine, morning sunlight exposure, and a dark sleep environment are non-negotiables. Just like children, adults thrive on a structured sleep routine.
Daily movement – Exercise isn’t just about gym sessions. Try to incorporate movement snacks—taking the stairs, post-meal walks, stretching, gardening, playing with kids or pets—all helps to keep circulation strong and mobility intact.
Stay hydrated – Most people don’t drink enough water. Aim for at least 2 litres daily. I start my morning with a pint of water to give me a head start on hydration.
Once these foundations are in place and symptoms persist, targeted functional testing can help uncover deeper imbalances.
As I mentioned, there are two specific tests I use regularly in my practice: Vitamin D testing and Metabolic Balance blood tests.
Vitamin D: An Important Test Worth Considering
Living in the Northern Hemisphere, most people don’t get enough sun exposure—especially in winter—for their bodies to produce adequate Vitamin D. While some foods (e.g. eggs, oily fish, mushrooms and fortified cereals) contain Vitamin D, diet alone rarely provides sufficient levels. The UK government recommends supplementation from October to March, or year-round for at-risk individuals.
Why is Vitamin D So Important?
Vitamin D is technically a steroid hormone (not just a vitamin), made from cholesterol and converted into its active form by the liver and kidneys. It plays a crucial role in:
Bone, teeth and muscle health (by regulating calcium and phosphate levels)
Immune system modulation (reducing inflammation and strengthening the gut barrier)
Hormonal balance (influencing sex hormones and stress response)
Cardiovascular health (impacting blood pressure regulation)
Brain health and mood regulation (linked to Seasonal Affective Disorder and anxiety/depression)
Insulin sensitivity and metabolic function (affecting weight and energy levels)
Many factors can interfere with Vitamin D production and absorption, including aging, stress, obesity, gut health issues, and even wearing sunscreen. Common deficiency symptoms include fatigue, mood swings, joint pain, poor immunity, and difficulty regulating blood sugar.
Why Test Instead of Just Taking a Supplement?
Vitamin D is fat-soluble, meaning excess amounts get stored and accumulate in the body rather than being excreted. Over-supplementation can cause calcium build-up, kidney stones, and toxicity symptoms. Testing allows for personalised dosing, ensuring optimal levels without risk.
Vitamin D testing is affordable and accessible—a simple finger-prick home test or in some cases, GPs may offer it for free. If you're unsure about your levels, testing is a smart first step. I do offer a Vitamin D check includes the test, checking for any contraindications and recommended dosage to achieve optimal levels safely.
Metabolic Balance: A Personalized Nutrition Approach
The second test I regularly use is the Metabolic Balance blood test, which forms the basis of a tailored nutrition programme. By analysing your unique blood markers, this test identifies the optimal real foods for your body, ensuring you receive the right balance of nutrients, vitamins, and minerals to restore health and regulate metabolism.
The results form will be used to generate a personalised and phased nutrition plan from Metabolic Balance so you’ll know exactly what, when & how much to eat so that your body naturally start releasing extra weight (without you feeling hungry!). As you move through the different phases, you will learn how to eat intuitively, making healthy eating (without deprivation) second nature.
Just to mention that not everyone who follows a Metabolic Balance wishes to lose weight. There are many health benefits to resetting your metabolism and reduce systemic inflammation. It is a blueprint to learning how to nourish your body to promote optimal health.
Final Thoughts: Test Smart, Not Fast
Functional testing can be a powerful tool, but only when used at the right time. Before diving into expensive assessments, lay the groundwork with fundamental health habits—balancing blood sugar, improving gut health, managing stress, prioritizing sleep, staying active, and hydrating properly. In most cases, these steps alone lead to significant health improvements.
Once all foundations are in place and symptoms persist, then choosing the right functional test will help to provide valuable insights in what may be going on. And at this point it will be worth the investment.
With the exception of Vitamin D testing or the Metabolic Balance blood tests (as this forms the basis of the programme), testing should be a strategic next step, not the first port of call.
Thank you for reading this blog and I hope that you found it thought provoking. Please click here to either complete an enquiry form or book a call if you want to explore whether functional testing is right for you or if you'd like support in building a strong foundation for your health and wellbeing. I'd love to help!
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