Vitamin D Test: Purpose, Normal Range and Price

Key facts about the Vitamin D3 test
Also Known As	25-Hydroxy Vitamin D Test, 25(OH)D Test, Vitamin D3 Test, Calcidiol Test
Sample Type	Blood (serum)
Fasting Required	Not strictly required; follow doctor's advice if part of a broader panel
Report Delivery	Within 24 hours
Age Group	All ages
Gender	All
Test Type	Chemiluminescent immunoassay (CLIA) or LC-MS/MS
Units	ng/mL or nmol/L

The Vitamin D test, formally known as the 25-Hydroxy Vitamin D test or 25(OH)D test, is a blood test that measures the level of calcidiol, the primary storage and transport form of Vitamin D in the body. This is the correct and most clinically meaningful form to measure as it reflects both dietary intake and skin synthesis combined, providing an accurate picture of the body's total Vitamin D reserves. Vitamin D is essential for calcium absorption, bone mineralisation, immune regulation, muscle function, and the prevention of several chronic diseases. Vitamin D deficiency is the single most prevalent nutritional deficiency in India. Despite abundant sunlight, studies estimate that 70 to 90% of Indians across all age groups, geographies, and socioeconomic backgrounds have insufficient or deficient Vitamin D levels. This paradox is explained by limited outdoor sun exposure, widespread use of sunscreen and full-body clothing, darker skin pigmentation requiring more sunlight for Vitamin D synthesis, and near-absent dietary sources of Vitamin D in predominantly vegetarian Indian diets. Deficiency causes rickets in children, osteomalacia and osteoporosis in adults, muscle weakness, recurrent infections, and is increasingly linked to increased risk of diabetes, cardiovascular disease, autoimmune conditions, and depression. The test involves a simple blood draw completed in under five minutes.

Doctors prescribe a Vitamin D test in the following situations: Investigating bone pain, muscle weakness, and fatigue in patients where Vitamin D deficiency is the most common and correctable underlying cause, particularly in women of reproductive age, elderly individuals, and those with limited sun exposure. Diagnosing rickets in children with bowed legs, delayed walking, dental abnormalities, and growth retardation where low Vitamin D alongside elevated alkaline phosphatase and low calcium confirms nutritional rickets requiring urgent supplementation. Evaluating osteoporosis and unexplained bone loss in adults where Vitamin D deficiency is a major and frequently overlooked correctable contributor to accelerated bone density loss and fracture risk. Screening high-risk groups including vegetarians, vegans, exclusively breastfed infants, elderly patients, individuals with obesity, those with malabsorption syndromes, and patients on anticonvulsant or glucocorticoid therapy where deficiency is highly prevalent. Monitoring Vitamin D supplementation therapy in patients already on oral or injectable Vitamin D to confirm that levels are rising adequately and that the dose is achieving the therapeutic target range. Investigating recurrent infections, autoimmune conditions, and inflammatory diseases where Vitamin D plays a critical immunomodulatory role and deficiency is a recognised contributing factor to immune dysregulation. Evaluating patients with chronic kidney disease, liver disease, and malabsorption conditions including coeliac disease and inflammatory bowel disease where Vitamin D absorption and activation are significantly impaired.

The Vitamin D test measures the concentration of 25-Hydroxy Vitamin D in the blood, reported in nanograms per millilitre (ng/mL) or nanomoles per litre (nmol/L). Normal Vitamin D Range in India The standard classification used across most Indian endocrinology and diagnostic centres, aligned with international guidelines, is as follows. A Vitamin D level below 20 ng/mL is classified as deficient and requires therapeutic supplementation. A level between 20 and 30 ng/mL is classified as insufficient and warrants supplementation particularly in symptomatic patients. A level between 30 and 100 ng/mL is considered optimal and sufficient for bone health and overall physiological function. Interpreting Vitamin D Results A Vitamin D level below 12 ng/mL represents severe deficiency and is associated with active rickets in children, osteomalacia in adults, significant muscle weakness, and markedly impaired immune function. High-dose loading supplementation under medical supervision is typically required at this level. A Vitamin D level between 12 and 20 ng/mL represents moderate deficiency and is the most commonly encountered range in Indian patients, causing subtle but clinically significant symptoms including fatigue, bone aches, and reduced immunity that are frequently misattributed to other causes. A Vitamin D level above 100 ng/mL is potentially toxic and associated with hypercalcaemia, kidney stones, and calcification of soft tissues. Vitamin D toxicity is almost exclusively caused by excessive supplementation rather than sun exposure or diet.

No fasting is strictly required for the Vitamin D test alone. However if Vitamin D is part of a broader panel that includes fasting parameters, fast as advised by your doctor. Our team confirms preparation requirements at the time of booking. Do not take Vitamin D supplements on the morning of the test unless specifically advised by your doctor, as a recently ingested dose can transiently raise serum levels and may not accurately reflect your true baseline status. Inform the phlebotomist about all medications and supplements you are currently taking, particularly Vitamin D supplements, calcium tablets, anticonvulsants, glucocorticoids, and antifungal medications, as these directly influence Vitamin D levels and must be disclosed for accurate interpretation. Inform your doctor if you have recently had significant sun exposure as prolonged sunlight exposure can transiently raise Vitamin D levels above your typical baseline. Stay normally hydrated before sample collection.

If you are booking through the SecondMedic platform the Vitamin D test price starts at approximately Rs. 2,299. The exact price will be confirmed at the time of booking through SecondMedic. If your doctor has prescribed multiple tests alongside Vitamin D, SecondMedic health packages include Vitamin D as part of a broader bone health, nutritional deficiency, or preventive health panel at a significantly lower combined price.

SecondMedic provides home sample collection for Vitamin D test across all major areas in India. You do not need to visit a lab or collection centre. A certified and trained phlebotomist comes to your home or workplace at your chosen time, collects the sample using sterile single-use equipment, and ensures it is transported to the NABL-accredited lab within the required time window for accurate processing. Please note that SecondMedic provides free home sample collection on all tests priced above Rs. 300. Our team will check your pincode and confirm if your address falls under our free sample collection eligibility criteria, which depends upon the lab location and phlebotomist availability. Home collection is available between 7 AM and 10 PM, seven days a week, including Sundays and public holidays. Enter your pincode on the booking page or call our helpline to confirm availability at your address.