Why Most Swedes Are Vitamin D Deficient — And What To Do About It

Vitamin D in Sweden

Sweden’s northern latitude means that during the darker months of the year, the sun is too low in the sky for the skin to produce meaningful amounts of vitamin D. As a result, vitamin D levels tend to fall during the winter, particularly in people who get little sun exposure or have a low dietary intake.

Vitamin D is important for several aspects of health, including normal immune function, bone health, and muscle function. Swedish data show a clear seasonal variation in vitamin D levels, with a greater proportion of adults having levels below 50 nmol/L in the winter than in the summer.

What are the symptoms of low vitamin D?

Low vitamin D does not always cause noticeable symptoms. When levels are low, some people may experience fatigue, muscle weakness, aches, or low mood. These symptoms are common and can have many different causes, so a blood test is the best way to determine whether vitamin D status may be contributing.

How to test your vitamin D levels

The standard blood test measures **25-hydroxyvitamin D (25-OH-D)**, which gives a good indication of your vitamin D status.

In Sweden, levels above **50 nmol/L** are generally considered sufficient, while levels below 30 nmol/L indicate a risk of deficiency according to Nordic nutritional recommendations.

At Wellth, we use **75–125 nmol/L as a practical target range** when assessing vitamin D status as part of a broader health picture. This is a lifestyle and nutritional target, rather than a clinical definition of deficiency.

What can you do about it?

For people living in Sweden, maintaining adequate vitamin D intake during the winter months may require attention to both diet and supplementation. The amount needed varies depending on factors such as sun exposure, diet, age, body composition, and individual vitamin D status.

Rather than automatically taking a high dose, testing your **25-OH-D level** can show where you are starting and help determine whether supplementation is appropriate. If you do supplement, vitamin D3 (cholecalciferol) is commonly used and is best taken with a meal containing some fat.

If you take vitamin D regularly, a repeat blood test after around **8–12 weeks** can help show how your level has improved.