Vitamin D Test (25-Hydroxy)

• Diagnose bone conditions:
  • Rickets in children (bone malformation and increased fracture risk)
  • Osteomalacia in adults (weak and soft bones)
• Monitor vitamin D replacement therapy: See if treatment is raising vitamin D levels effectively.
• Identify secondary hyperparathyroidism: Low vitamin D can be a contributing factor.
• Assess overall vitamin D status: Measure the body's current vitamin D levels.
• Additional testing for kidney disease: Patients with kidney problems might require a different vitamin D test (1,25 dihydroxy vitamin D).

The Vitamin D Total-25 Hydroxy Plasma/Serum Test measures the level of 25-hydroxyvitamin D (25(OH)D) in your blood. It is the major storage form of vitamin D in the body. By measuring 25(OH)D levels, the test indirectly reflects how much vitamin D is stored and available for use. This is the most widely used and accurate test to assess your overall vitamin D status.

During a vitamin D blood test, a health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Deficiency can indicate an increased risk of:

• Osteoporosis (weak bones and fractures)
• Rickets in children (bone malformation)
• Osteomalacia in adults (bone softening)

Toxicity is rare, but possible with excessive vitamin D supplementation. Symptoms include nausea, vomiting, poor appetite, constipation, and weakness.

Here are the groups of people who might benefit from getting a Vitamin D Total-25 Hydroxy Plasma/Serum Test:

• People with symptoms of vitamin D deficiency:

  • Bone pain
  • Muscle weakness
  • Fatigue
  • Frequent fractures

• Individuals at higher risk of deficiency:

  • Limited sun exposure (due to geographical location, clothing habits, or use of sunscreen)
  • Darker skin pigmentation (less efficient vitamin D synthesis from sunlight)
  • Certain medical conditions affecting fat absorption (e.g., Crohn's disease, celiac disease)
  • Older adults (skin becomes less efficient at producing vitamin D with age)

• Those taking medications that can interfere with vitamin D metabolism:

  • Some medications like corticosteroids or certain anticonvulsants

• People undergoing monitoring of vitamin D replacement therapy:

  • To ensure the treatment is effectively raising vitamin D levels

• Pregnant or breastfeeding women:

  • Vitamin D is crucial for fetal bone development and maintaining maternal health.

• Additionally, a doctor might recommend this test for individuals with:

• Unexplained bone pain or weakness
• Muscle aches
• Difficulty maintaining balance or increased falls
• A family history of osteoporosis

There are no specific preparations required for the test. However, it is recommended that you consult with your healthcare provider before taking the test, as they may have specific instructions or recommendations based on your individual medical history and current health status.

The body receives vitamin D from cutaneous production and dietary intake; the closest indicator of this is currently thought to be the total serum 25(OH)D level. The total 25 (OH)D level reference range is 20–100 ng/mL.

Children who have rickets have weakening and thinning of their bones, which is typically caused by a severe and sustained vitamin D deficit. Rickets can also occur due to uncommon hereditary issues.

It is a common practice to test serum calcium, phosphorus, and parathyroid hormone in addition to vitamin D levels.

• 25-hydroxyvitamin D
• 25(OH)D
• Cholecalciferol test
• Calcidiol test
• 25-OH Vitamin D Test
• 25-hydroxycholecalcifoerol Test