Lab test

Vitamin D Blood Test - Online D 25-Hydroxy Deficiency Test

The Vitamin D Blood Test measures the level of 25-hydroxy vitamin D, also called calcidiol, the main form of vitamin D circulating in the blood.

Typical price

From $118

Results

1-3 business days

Preparation

See preparation notes below

Sample

Blood draw or sample collection at a local center

The Vitamin D Blood Test measures the level of 25-hydroxy vitamin D, also called calcidiol, the main form of vitamin D circulating in the blood. Vitamin D is obtained from sunlight, food, and drinks and is important for bone health, calcium balance, and normal immune and muscle function. This test is used to check for vitamin D deficiency or to monitor supplementation. Because 25-hydroxy vitamin D reflects overall vitamin D status, it is the standard measurement for assessing whether levels are low, sufficient, or high.

• 25-Hydroxy Vitamin D (Calcidiol) Measures the main circulating form of vitamin D to assess overall vitamin D status.

• People with limited sun exposure or diets low in vitamin D.
• Individuals with bone, muscle, or joint concerns their provider wants to evaluate.
• People taking vitamin D supplements who want to monitor their level.
• Anyone with conditions that may affect vitamin D absorption or metabolism.
• People whose provider is assessing overall nutritional or bone health.

• No fasting is required unless your provider gives other instructions.
• Continue your usual medications and supplements, but tell your provider what you take.
• If you use vitamin D supplements, mention the dose and timing so the result can be interpreted.
• Follow the sample collection guidance provided with your kit.

The report shows your 25-hydroxy vitamin D level compared with the reference range. A low level may suggest vitamin D deficiency, which can affect bone and muscle health, while a high level may reflect excessive supplementation. The result is interpreted with your diet, sun exposure, and any supplements you take. Because target levels can vary by individual, discuss your result with a healthcare provider, who can decide whether any changes are appropriate.

• Alabama
• Alaska
• Arizona
• Arkansas
• California
• Colorado
• Connecticut
• Delaware
• Florida
• Georgia