Vitamin D deficiency in the Netherlands: how serious is it?

The Netherlands lies at 52 degrees north. That matters, because between October and March the sun sits too low to deliver enough UVB radiation for your skin to make vitamin D. No matter how much time you spend outside, in that period your body produces almost none. This article is part of our overview of vitamin deficiency and answers a question many people ask: how serious is a vitamin D deficiency really?

Is a vitamin D deficiency dangerous?

A mild, short-lived vitamin D deficiency is usually not dangerous and often causes no symptoms. A large or long-term shortage is different: it can weaken your bones, reduce muscle strength and make you more prone to infections. The consequences build up slowly, so you notice them late.

• Bone loss - in adults a prolonged deficiency can cause osteomalacia (painful bone softening), in children rickets with skeletal deformation.
• Higher fall risk - vitamin D is needed for normal muscle strength. A shortage raises the risk of falls and fractures, especially in older adults.
• Reduced resistance - a deficiency is associated with greater susceptibility to infections.

For the symptoms and testing of a deficiency, read vitamin D deficiency: symptoms, causes and how to test.

Vitamin D deficiency and mental health

There is growing evidence that vitamin D plays a role in regulating your mood. A shortage can relate to low mood, irritability and low energy, especially in autumn and winter. Vitamin D is rarely the only cause, so see it as one of several possible factors.

Complaints such as ongoing low mood belong with your GP. A vitamin D value can help rule one possible factor in or out, but it does not replace a conversation about your mental health.

Why is the Netherlands at extra risk?

A large share of the Dutch population is estimated to have a suboptimal vitamin D level, with higher rates in risk groups. A combination of factors makes a shortage almost unavoidable without conscious measures:

• Geographic location - at 52 degrees north, UVB radiation is insufficient from October to March, even on a sunny day.
• Indoor lifestyle - most of us spend the larger part of the day indoors. Glass blocks UVB radiation completely.
• Sunscreen - correct use of sunscreen (SPF 30+) blocks most UVB radiation. Necessary for skin cancer prevention, but it slows vitamin D production.
• Diet - there are few natural food sources of vitamin D.
• Ageing - the skin's efficiency at making vitamin D declines with age.

Risk groups

• People with darker skin - melanin blocks part of the UVB radiation.
• Older adults (70+) - reduced skin production, less time outside and lower food intake stack the risk.
• People who wear covering clothing
• People who mainly work or live indoors
• Pregnant and breastfeeding women
• People with obesity - vitamin D is stored in fat tissue.

Supplementation: the Health Council advice

• Children 0-4 years - 10 ug (400 IU) a day, year round
• Adults 4-70 with lighter skin - 10 ug a day if you are outdoors too little
• Women 50+ and men 70+ - 20 ug (800 IU) a day
• People with darker skin or covering clothing - 10-25 ug a day
• Pregnant women - 10 ug a day

Vitamin D3 (cholecalciferol) is preferred over D2. Take the supplement with a meal containing fat, as vitamin D is fat-soluble and is then better absorbed. Also read how much vitamin D per day you need.

The link with calcium

Vitamin D and calcium work closely together. Vitamin D is needed to absorb calcium from your food. With a shortage, calcium absorption drops and your body draws calcium from your bones. That is why checking your calcium level is useful when a deficiency is suspected.

When is testing worthwhile?

The Health Council does not advise screening the whole population for vitamin D. Testing is worthwhile if you have symptoms that fit a deficiency, belong to a risk group, have osteoporosis, or want to know whether your current supplementation is enough. The blood test measures 25-hydroxyvitamin D (25(OH)D). Check your vitamin D value or build a custom blood test.

My advice: do not panic over a low number, but do not ignore it either. 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.