Vitamins & Nutrients
Vitamin D (25-OH)
Vitamins & Nutrients
Essential for bone health, immunity and mood. Most Swedes are deficient in winter.
VAT-exempt medical service
Every cell in your body has vitamin D receptors, highlighting how vital this nutrient is to overall health. Your body synthesises vitamin D from sunlight, yet people living in the northern hemisphere rarely get enough from sun exposure alone. Even those in warmer climates are frequently deficient. Optimal vitamin D levels are linked to better bone density, stronger immune function and reduced risk of several chronic diseases. A simple blood test measuring 25-hydroxyvitamin D reveals your current status.
Testing is recommended if you live in a northern climate, have limited sun exposure, have dark skin, cover up outdoors, are over 50, are pregnant, or take medications such as corticosteroids or antacids that affect vitamin D metabolism. It is also useful for monitoring supplementation progress and for those with genetic variants that impair vitamin D absorption.
What a high value can mean
Very high vitamin D levels, typically above 250 nmol/L, may indicate toxicity, most often from excessive supplementation. Rarely, conditions such as sarcoidosis can elevate levels. Symptoms include nausea, vomiting, weakness and kidney problems. The optimal range is generally 75 to 150 nmol/L.
What a low value can mean
Low vitamin D means your body is not producing or absorbing enough of the vitamin. Deficiency is defined as levels below 50 nmol/L, and insufficiency as 50 to 75 nmol/L. Causes include limited sun exposure, dark skin, obesity, malabsorption conditions (celiac disease, IBD), liver or kidney disease, and certain medications. Severe deficiency causes rickets in children and osteomalacia in adults.
No fasting or special preparation is needed. Bring valid ID to the lab. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.
Order your test
Choose your test and pay online. Your lab referral is created straight away.
Give your sample
Visit any of our partner sampling locations. No appointment needed at most of them.
The lab analyses it
Your sample is analysed at an accredited Swedish laboratory.
Get your results
Your values appear in your account with reference ranges and an explanation of each marker.
Most experts consider 75 to 150 nmol/L optimal. Levels below 50 nmol/L are classified as deficient, and some research suggests 90 to 120 nmol/L may be ideal for disease prevention.
It is very difficult. Oily fish, egg yolks and fortified foods contribute small amounts, but sunlight and supplementation are typically necessary to achieve optimal levels.
Dosage depends on your current levels, body weight and individual absorption. A healthcare provider can recommend the right dose after reviewing your blood test results.
Many practitioners recommend combining vitamin D with K2, as K2 helps direct calcium into bones rather than soft tissues. Discuss this with your provider.