Vitamin D deficiency is one of the most common deficiencies in the Netherlands. Limited sunlight hours, especially in winter, leave much of the population with low levels. This article is part of our overview of vitamin deficiency and its symptoms. Below you read what the symptoms of a vitamin D deficiency are and how to test for it.
Why vitamin D matters
Vitamin D is technically a hormone and plays a role in:
- Calcium absorption and bone health (osteoporosis prevention)
- Immune system function
- Muscle function
- Mood and mental health
- Cell division and tissue growth
Vitamin D deficiency symptoms
The symptoms of a vitamin D deficiency are often subtle and not always recognised. Common complaints are ongoing fatigue, muscle and bone pain and a low mood. Because these complaints are broad, they give no certainty without a blood test.
- Fatigue - one of the most common complaints. Fatigue can also point to a vitamin B12 deficiency.
- Muscle weakness or pain - mainly in legs and back
- Bone pain - diffuse pain, mainly in back, hips and legs
- Low mood - vitamin D influences serotonin production
- Frequent illness - reduced resistance
- Slow wound healing
- Hair loss - in severe deficiencies
Normal values (nmol/L)
- Above 75 nmol/L - optimal
- 50 to 75 nmol/L - sufficient
- 30 to 50 nmol/L - insufficient
- Below 30 nmol/L - deficient
Who is at risk of a vitamin D deficiency?
- Everyone in the Netherlands - from October to April sunlight is insufficient for vitamin D production
- People with darker skin - melanin reduces vitamin D production in the skin
- Older adults - the skin becomes less efficient at producing vitamin D
- People who are rarely outdoors - home and office workers
- People with overweight - vitamin D is stored in fat tissue and is less available
- Women who cover their skin
A long-term deficiency is not harmless. Read more about how serious a vitamin D deficiency is and its consequences.
Correcting a vitamin D deficiency
- Sunlight - 15 to 30 minutes a day in summer (arms and face bare, without sunscreen). Insufficient in the Dutch winter.
- Diet - oily fish, eggs, fortified dairy. Diet alone is rarely enough.
- Supplements - the Health Council advises 10 ug a day for adults up to 70 and 20 ug a day for over-70s. Also read how much vitamin D per day you need. With a confirmed deficiency your doctor may advise a higher dose.
Frequently asked questions
When is the best time to test?
At the end of winter (February and March) your vitamin D level is lowest. That is the most informative moment to test. After summer your level is highest.
Can I take too much vitamin D?
Not through sunlight and food. Through supplements an overdose is possible at very high doses (sustained above 100 ug a day). Follow your doctor's advice and have your level checked.
Does a tanning bed help for vitamin D?
Tanning beds mainly produce UVA radiation, while your skin needs UVB to make vitamin D. They are therefore not advised as a vitamin D source and raise the risk of skin cancer.
Want to measure your vitamin D? Check your vitamin D value or build a custom blood test. Every blood test result at Vitalcheck includes a professional assessment by a BIG-registered doctor. A blood value is not a diagnosis: always discuss symptoms and treatment decisions with your GP.
References
- Health Council of the Netherlands. Dietary reference values for vitamins and minerals. 2018.
- RIVM. At most a quarter of the Dutch population has a vitamin D deficiency in winter. 2023.
- Thuisarts.nl / NHG. Vitamin D. Accessed 2026.
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