Vitamin D3 - 25(OH)D concentration test

Vitamin D occurs in two forms: D2 and D3, which are obtained from food and produced in the skin under the influence of UVB radiation. To maintain an adequate vitamin D level and minimize the risk of deficiency, vitamin D supplementation is often necessary.

The blood sample for the test is collected from a vein in the elbow area. This is a standard procedure that usually takes only a short time.

The vitamin D test can be performed within 3 months from the date indicated in the order confirmation.
To complete the test, visit the selected collection point during its opening hours.

When should the vitamin D3 test – 25(OH)D measurement – be performed?

The vitamin D3 level test is recommended if symptoms of deficiency occur or if vitamin D excess is suspected.

Vitamin D deficiency

If the vitamin D level in the body is too low, it may lead to:

• rickets in children,

• bone softening (osteomalacia) or osteoporosis in adults,

• bone fractures and degenerative bone disorders,

• weakness of the body and reduced immunity,

• insomnia,

• increased risk of autoimmune diseases.

Who is particularly at risk of vitamin D deficiency?

• people suffering from chronic kidney disease, including nephrotic syndrome,

• people taking certain antiepileptic drugs or HAART therapy (HIV treatment),

• people with malabsorption syndromes,

• patients after bariatric (obesity) surgery,

• people with tuberculosis or sarcoidosis (granuloma formation), certain lymphomas or hyperparathyroidism,

• people with autoimmune diseases.

Vitamin D3 deficiency may negatively affect many vital processes in the body – therefore maintaining its optimal level is extremely important.

Vitamin D excess

Excess vitamin D, although rare, may cause serious symptoms and health effects. The most important include:

• persistent weakness, drowsiness and fatigue,

• emotional confusion, hyperactivity and irritability,

• loss of appetite,

• abdominal pain, constipation, nausea, diarrhea, vomiting,

• a metallic taste in the mouth.

Vitamin D supplementation

Measurement of vitamin D3 and its metabolites in serum should not be performed in patients without a significantly increased risk of vitamin D3 deficiency. Symptoms of fatigue alone are not an indication for vitamin D testing.

Supplementation with over-the-counter preparations and increased sun exposure during the summer months are usually sufficient to correct vitamin D3 deficiency. Taking vitamin D at a dose of up to 4000 IU per day does not require baseline vitamin D testing or monitoring during supplementation. This dose does not cause overdose.

Consider performing the test if you are at risk of vitamin D3 deficiency.

What does the vitamin D3 test – 25(OH)D measurement – diagnose?

The test allows assessment of vitamin D levels in the body and may help detect:

• vitamin D deficiency,

• vitamin D excess,

• disorders related to vitamin D metabolism.

How to prepare for the vitamin D3 test – 25(OH)D measurement?

The vitamin D3 level test does not require special preparation or fasting, which means it can be performed at any time of the day.

If you take vitamin D3 supplements, you do not need to stop taking them before the test.

It is recommended to drink a few glasses of water before the test to increase blood volume, which may make blood collection easier.

Preparation for the test may vary depending on the facility performing it.