Test ID: B-223
Could Vitamin D Deficiency Be Behind Your Fatigue, Pain, or Low Mood?
Vitamin D deficiency is one of the most widespread and underdiagnosed nutritional issues in the UK — affecting an estimated 1 in 5 adults. It often has no obvious symptoms, yet it silently increases the risk of serious health conditions. If you recognise any of the following, a Vitamin D test could be the missing piece:
- Persistent fatigue or low energy that doesn’t improve with rest
- Bone pain, aching joints, or muscle weakness
- Frequent illness or infections (low immunity)
- Low mood, depression, or seasonal mood changes
- Hair loss or slow hair growth
- Chronic back pain or musculoskeletal discomfort
- Spending most of your time indoors or living in the UK/northern latitudes
- Dark skin tone (requires more sun exposure to produce Vitamin D)
- Overweight or obese (Vitamin D can become trapped in fat tissue)
- Taking Vitamin D supplements and unsure if your levels are optimal
- Elderly or at risk of osteoporosis or fractures
What Is Vitamin D and Why Does It Matter?
Vitamin D is a prohormone — not just a vitamin — that plays a critical role in dozens of body systems. Most of it is produced by the skin in response to sunlight, with very little coming from diet alone. In the UK, low sunlight levels make deficiency extremely common, particularly in autumn and winter.
Research links Vitamin D deficiency to a wide range of serious conditions, including:
- Osteoporosis and increased fracture risk
- Cardiovascular disease and stroke
- Type 1 and Type 2 diabetes
- Autoimmune conditions (multiple sclerosis, rheumatoid arthritis)
- Depression and mood disorders
- Certain cancers (breast, colon)
- Chronic musculoskeletal pain and fibromyalgia
Optimal Vitamin D levels are generally considered to be 32–100 ng/mL. Levels below 20 ng/mL indicate deficiency; levels below 32 ng/mL are considered low. Toxicity may occur above 150 ng/mL, making accurate testing essential for safe supplementation.
What This Test Measures
This is one of the most precise Vitamin D tests available, using LC-MS/MS technology to independently measure both forms:
- Vitamin D2 (Ergocalciferol) – The form found in plant-based foods and many supplements
- Vitamin D3 (Cholecalciferol) – The form produced by sunlight and found in animal-based foods
- Total Vitamin D (25-OH) – The calculated combined level used to assess overall Vitamin D status
Measuring D2 and D3 separately is important for anyone supplementing, as it shows exactly which form is contributing to your levels and whether your supplementation is working.
How It Works
- Order your kit — delivered to your door
- Collect your sample at home — a simple finger-prick blood spot; no clinic or GP visit needed
- Post your sample to our CLIA-certified laboratory using the instructions provided
- Receive your results by email within 3–5 working days of the lab receiving your sample
What You Get With Your Results
Your personalised report includes:
- Your D2, D3, and Total Vitamin D levels displayed clearly in graphics and numbers
- A written interpretation by a Hormone Specialist PhD Doctor
- Guidance on whether your levels are deficient, low, or optimal, and what to do next
Who Is This Test For?
This test is suitable for men and women who want to:
- Check Vitamin D levels due to symptoms of deficiency
- Monitor supplementation to ensure safe and effective dosing
- Assess Vitamin D as part of a broader health or hormone check
- Reduce risk of osteoporosis, immune dysfunction, or mood disorders
- Get a precise D2 vs D3 breakdown rather than a total-only result
Key Information
- Measures D2 and D3 independently using advanced LC-MS/MS technology
- Collect your sample from home and post to our lab — no clinic visit required
- Results delivered by email within 3–5 working days
- Laboratory fee included — no hidden costs or additional charges
- Valid for 12 months from the date of purchase
- Analysed by a CLIA-certified laboratory with over 11 million tests performed
- Customers are responsible for posting their sample to the laboratory