Vitamin D
What It Is
Vitamin D is a fat-soluble vitamin produced by the skin in response to sunlight and essential for bone health and immune function.
Why It Matters
Vitamin D deficiency is extremely common in the UK, particularly in Scotland, and is linked to bone disease, fatigue, and immune dysfunction.
If Levels Are High
Very high vitamin D (toxicity) is rare and usually results from excessive supplementation.
If Levels Are Low
Low vitamin D can cause fatigue, bone pain, muscle weakness, and increased fracture risk.
Preparation
No special preparation required.
How Often to Test
Annually, particularly in autumn/winter. More often if supplementing.
Panels Including This Marker
Standard Screen
Next Day · 16 markers
Advanced GP 2
72 Hours · 28 markers
Tired All The Time
48 Hours · 47 markers
Long Covid
72 Hours · 33 markers
Sports Performance
48 Hours · 72 markers
Lifestyle Screen
48 Hours · 36 markers
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Important Disclaimer
This information is for educational purposes only and does not constitute medical advice or diagnosis. Results should be interpreted in clinical context by a qualified healthcare professional. If you have severe symptoms or urgent concerns, seek urgent medical help.