25 OH Vitamin D

Vitamin

Report in 4Hrs

At Home

No Fasting Required

Details

Assesses 25-hydroxyvitamin D levels to determine deficiency, affecting bone strength and immune function.

₹299₹1,280

77% OFF

25 OH Vitamin D - Comprehensive Medical Test Guide

Why is it done?
- Test Measurement: This test measures the level of 25-hydroxyvitamin D in the blood, which is the most reliable indicator of vitamin D status in the body. It reflects vitamin D obtained from sun exposure, diet, and supplements.
- Primary Indications: Evaluate vitamin D deficiency or insufficiency; assess risk for bone diseases (osteoporosis, osteomalacia, rickets); evaluate symptoms of deficiency (muscle weakness, bone pain, fatigue); monitor patients with malabsorption disorders; assess calcium metabolism disorders; evaluate patients with chronic kidney or liver disease.
- Typical Circumstances: Routine screening in patients with risk factors; investigation of bone pain or muscle weakness; follow-up of known deficiency; seasonal evaluation (particularly in winter months or high-latitude regions); monitoring of patients on vitamin D supplementation therapy; assessment before starting osteoporosis treatment.
Normal Range
- Reference Ranges: The reference ranges vary slightly between laboratories but generally follow these guidelines:
- Optimal/Sufficient: 30-100 ng/mL (75-250 nmol/L) - Associated with good bone health and overall health
- Insufficient: 20-29 ng/mL (50-75 nmol/L) - May increase risk of bone disease and other health issues
- Deficient: <20 ng/mL (<50 nmol/L) - Associated with significant risk of osteomalacia, rickets, and impaired bone metabolism
- Potentially Toxic: >150 ng/mL (>375 nmol/L) - Risk of hypercalcemia and toxicity (rare, usually from excessive supplementation)
- Units of Measurement: ng/mL (nanograms per milliliter) in the US and Canada; nmol/L (nanomoles per liter) in most other countries. Conversion: 1 ng/mL = 2.5 nmol/L
- Interpretation Guide: Normal results indicate adequate vitamin D status for bone health and metabolic function. Values below normal indicate insufficient sun exposure, dietary intake, or absorption issues requiring intervention. Elevated values may suggest excessive supplementation or toxicity requiring investigation.
Interpretation
- High Results (>100 ng/mL or >250 nmol/L): May indicate excessive vitamin D supplementation; possible hypercalcemia; requires investigation for causes and assessment of calcium levels; can lead to symptoms including nausea, vomiting, weakness, and renal complications if severely elevated.
- Optimal Results (30-100 ng/mL or 75-250 nmol/L): Indicates adequate vitamin D status; sufficient for maintaining bone health, supporting immune function, and regulating calcium-phosphate metabolism; no intervention typically needed unless there are other clinical considerations.
- Low Results (<30 ng/mL or <75 nmol/L): Indicates vitamin D insufficiency or deficiency; risk of impaired calcium absorption leading to bone loss; may cause or contribute to osteomalacia, rickets, or secondary hyperparathyroidism; requires supplementation and investigation of underlying cause.
- Factors Affecting Results: Sun exposure (latitude, season, time of day, skin pigmentation); dietary intake; supplementation; malabsorption disorders (Crohn's disease, celiac disease, cystic fibrosis); kidney or liver disease; age and body composition; medications (anticonvulsants, glucocorticoids); genetic factors affecting vitamin D metabolism.
- Clinical Significance: Vitamin D is critical for calcium absorption and bone mineralization; deficiency increases fracture risk; associated with increased infection risk, impaired immune function, and possible links to certain cancers; plays role in muscle function, cardiovascular health, and neurological function; deficiency may contribute to depression and seasonal affective disorder.
- Result Patterns and Their Significance: Low vitamin D with high parathyroid hormone (PTH) suggests secondary hyperparathyroidism; low vitamin D with high alkaline phosphatase may indicate osteomalacia; seasonal variation in results is common; persistently low levels despite supplementation may suggest absorption problems or non-compliance.
Associated Organs
- Primary Organ Systems: Skeletal system (bones and cartilage); gastrointestinal system (site of vitamin D absorption); kidneys (activate vitamin D); parathyroid glands (regulate calcium and vitamin D metabolism); skin (produces vitamin D from sun exposure).
- Medical Conditions Associated with Abnormal Results: Osteoporosis; osteomalacia (soft bone disease in adults); rickets (in children); secondary hyperparathyroidism; chronic kidney disease; chronic liver disease; malabsorption syndromes (Crohn's disease, celiac disease, irritable bowel syndrome); cystic fibrosis; chronic pancreatitis; post-gastrectomy state.
- Diseases This Test Helps Diagnose: Vitamin D deficiency and insufficiency; osteomalacia (radiographically evident as Looser zones); hypophosphatemic rickets; familial hypophosphatemia; tertiary hyperparathyroidism; vitamin D-dependent rickets Type 1 and 2; hypervitaminosis D; assessment of kidney osteodystrophy in chronic kidney disease patients.
- Potential Complications of Abnormal Results: From deficiency: Increased fracture risk, muscle weakness, impaired wound healing, increased infection susceptibility, possible mood disturbances. From excess: Hypercalcemia causing nephrolithiasis (kidney stones), renal insufficiency, cardiac arrhythmias, band keratopathy, metastatic calcification, severe nausea and vomiting, confusion.
- Monitoring for Associated Conditions: Patients with chronic kidney disease require regular monitoring due to impaired vitamin D activation; elderly patients and those at fracture risk need periodic assessment; patients on anticonvulsants require monitoring due to accelerated vitamin D metabolism; transplant recipients may have altered vitamin D metabolism.
Follow-up Tests
- Recommended Follow-up Tests Based on Results: Serum calcium (total and ionized); serum phosphate; alkaline phosphatase (ALP); parathyroid hormone (PTH); 1,25-dihydroxyvitamin D (active form); magnesium; albumin; creatinine and estimated glomerular filtration rate (eGFR); 24-hour urine calcium.
- Imaging and Diagnostic Studies: Bone density scan (DEXA) for assessment of osteoporosis risk; radiographs to assess for rickets or osteomalacia; X-rays to evaluate for Looser zones characteristic of osteomalacia; spine imaging if vertebral fractures suspected.
- Further Investigations: Evaluation for malabsorption if deficiency persists despite supplementation (fecal fat, tissue transglutaminase antibodies, esophagogastroduodenoscopy); assessment for chronic kidney or liver disease; investigation for hereditary forms of vitamin D-dependent rickets; evaluation of anticonvulsant use or other medications affecting vitamin D metabolism.
- Monitoring Frequency: Baseline assessment followed by recheck 8-12 weeks after supplementation started; annual monitoring for asymptomatic patients with deficiency being treated; more frequent monitoring (every 3-6 months) for patients with chronic kidney disease, malabsorption disorders, or on high-dose supplements; seasonal reassessment may be beneficial in high-latitude regions.
- Related Tests Providing Complementary Information: PTH (inverse relationship with vitamin D); bone turnover markers (P1NP, CTX); metabolic panel; kidney function tests; liver function tests; magnesium and phosphate levels; tests for specific diseases (celiac serology, tissue transglutaminase antibodies); markers of bone metabolism for fracture risk assessment.
- Specialist Consultation: Endocrinology consultation for complex cases, hypercalcemia, or suspected genetic disorders of vitamin D metabolism; Nephrology consultation for patients with chronic kidney disease; Gastroenterology for evaluation of malabsorption disorders; Rheumatology for bone disease management.
Fasting Required?
- Fasting Requirement: NO - Fasting is NOT required for the 25 OH Vitamin D test. This test can be performed at any time of day without regard to meals or food intake.
- Time of Testing: Blood can be drawn in the morning or afternoon; no need to schedule specifically in relation to meals; vitamin D levels are relatively stable and not significantly affected by recent food intake or time of day.
- Medications and Supplements: No need to avoid medications before the test; continue taking all regular medications including vitamin D supplements as prescribed (unless directed otherwise by healthcare provider); do NOT stop vitamin D supplementation before the test as it would affect the accuracy of the result reflecting actual vitamin D status.
- Patient Preparation Requirements: No special preparation needed; can eat and drink normally before the test; wear loose-fitting clothing on the arm for convenient blood draw; inform phlebotomist of current vitamin D supplementation if monitoring therapeutic levels; stay hydrated (normal fluid intake is fine); arrive on time for the appointment.
- Specimen Collection: Blood sample collected via venipuncture using a standard 3-5 mL collection tube (usually a serum separator tube); minimal discomfort expected; no bleeding precautions required post-collection unless patient on anticoagulation therapy; specimen should be kept at room temperature and transported to laboratory promptly.
- Important Considerations: Vitamin D is fat-soluble and accumulates in the body over time, so results reflect long-term vitamin D status rather than recent intake; if testing for baseline status, may want to note date and any supplements or sun exposure patterns; seasonal variation exists (lower in winter, higher in summer); follow-up testing after 8-12 weeks of treatment allows adequate time for levels to reach new equilibrium.

How our test process works!