Why check vitamin D levels?

What is vitamin D?

Vitamin D is a secosteroid hormone with a wide range of effects in the body. It plays an important role in the absorption of dietary calcium and thus helps regulate calcium balance in the body.

Vitamin D reference values:

<25 nmol/L – deficiency

25–50 nmol/L – insufficient

50–250 nmol/L – sufficient

250 nmol/L – toxic

What is the role of vitamin D in the body?

Vitamin D plays a very important role in regulating calcium metabolism. In the case of vitamin D deficiency, calcium absorption from the intestine decreases, meaning the body cannot obtain sufficient calcium. This can lead to various health problems – bones become thinner and lose mineral density, teeth lose strength and deteriorate, and muscle function (including heart muscle function) worsens.

Which diseases are associated with vitamin D deficiency?

a) In adults, bone changes may lead to osteoporosis and an increased risk of fractures.

b) In children and adolescents, vitamin D deficiency promotes the development of skeletal disorders. Low levels may result in osteomalacia and rickets, Osgood–Schlatter disease, Sinding–Larsen–Johansson disease, Scheuermann’s disease, and in rare cases idiopathic juvenile (childhood) osteoporosis. Vitamin D deficiency also plays an important role in the development of a severe joint disease – Perthes disease. The prevalence of this disease is higher in Nordic countries, where vitamin D deficiency is widespread due to low sunlight intensity (the disease does not occur in equatorial regions).

c) Vitamin D plays a role in ensuring muscle contraction strength. Therefore, deficiency may lead not only to bone problems but also to reduced performance in young athletes and more frequent falls and fractures in older adults.

Where does the body get vitamin D from?

Vitamin D is produced naturally in the skin under the influence of UVB rays from sunlight, and during summer months this is usually sufficient to meet the body’s needs. In Estonia (59°N), the sun can be used as a source of vitamin D for only 3–4 months per year. For most of the year (from September to May), UVB radiation intensity is too low to trigger vitamin D synthesis in the skin, making supplementation necessary during autumn, winter, and spring.

Who is at the highest risk of vitamin D deficiency?

The risk of vitamin D deficiency is particularly high among people who, for health-related or other reasons, spend little time outdoors during summer (elderly individuals and people with limited mobility). In older adults, the skin’s ability to produce vitamin D also decreases significantly.

The risk of deficiency increases with physical activity, as muscles use existing vitamin D reserves during exercise. The risk is highest among indoor athletes who train mainly indoors (ball sports, young athletes in aesthetic sports, swimmers, etc.).

The following Terviseuuringud.ee packages include vitamin D testing:

Health Check Plus
Recreational Athlete Plus