Quick Facts
- Sample: Blood (plasma)
- Fasting: 12 hours recommended
- Turn-around: 5-7 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Detect deficiency early — catch low vitamin C before serious symptoms develop
- Monitor supplementation — verify your vitamin C intake is working effectively
- Assess nutritional status — understand if diet meets your body's antioxidant needs
- Support immune health — ensure adequate levels for optimal infection resistance
- No doctor visit required — order online and test at your convenience
- Fast, accurate results — advanced LC-MS/MS technology delivers precise measurements
Who Is This Test For?
- Individuals with limited dietary variety or poor fruit/vegetable intake
- People experiencing unexplained fatigue, weakness, or easy bruising
- Those with malabsorption conditions like Crohn's disease or celiac disease
- Smokers at higher risk for vitamin C depletion
- Individuals with chronic illness or kidney disease
- Anyone monitoring vitamin C therapy or supplementation effectiveness
How It Works – Just 3 Steps
- Order online — purchase your test without a doctor's referral
- Visit a lab — get your blood drawn at a nearby location
- Receive results — access confidential results in 5-7 business days online.
FAQ
What does this test measure? This test quantifies ascorbic acid (vitamin C) concentration in your plasma using advanced mass spectrometry technology (Mayo Clinic 2024).
Why is vitamin C important? Vitamin C supports collagen synthesis, immune function, iron absorption, and acts as a powerful antioxidant protecting cells from damage (NIH 2025).
Will supplements affect my results? Yes, vitamin C intake rapidly elevates plasma levels, so fasting and avoiding supplements before testing is important (CDC 2025).
How long until I get results? Typical turnaround is 5-7 business days after your blood sample reaches the laboratory.
Can I test at home? Blood collection requires venipuncture at a lab location; at-home finger-stick options are not available for this test.
More Details
What is the purpose of this test?
The Vitamin C Blood Test measures plasma ascorbic acid to evaluate your nutritional status and detect deficiency. Vitamin C is essential for collagen production, wound healing, immune defense, and iron absorption. This test helps identify vitamin C deficiency—including scurvy—before serious complications develop (Mayo Clinic 2024). Early detection allows you to adjust diet or supplementation, preventing symptoms like bleeding gums, joint pain, and impaired wound healing.
Who would benefit from this test?
This test is valuable for anyone concerned about nutritional adequacy. Individuals with limited dietary variety, chronic illnesses, malabsorption disorders (Crohn's disease, celiac disease, inflammatory bowel disease), kidney disease, or alcoholism face higher deficiency risk. Smokers have increased vitamin C requirements and deplete stores faster (NIH 2025). If you experience unexplained fatigue, easy bruising, nosebleeds, bleeding gums, slow wound healing, or frequent infections, testing can identify whether low vitamin C contributes to your symptoms.
When should I order a Vitamin C Blood Test?
Order this test if you have symptoms suggesting deficiency: fatigue, weakness, joint pain, bleeding gums, easy bruising, dry skin, or poor wound healing. Testing is also appropriate before starting supplementation to establish baseline levels, after several weeks of therapy to verify effectiveness, or when monitoring chronic conditions affecting nutritional status. Individuals with malabsorption disorders or those undergoing cancer treatment should consider periodic testing (ARUP Laboratories 2024).
How do I interpret the results?
Your results reflect plasma vitamin C concentration, indicating your body's current stores and nutritional adequacy.
Vitamin C Level below 0.2 mg/dL
- What it means: Deficiency (scurvy risk)
- Typical action: Immediate supplementation and dietary changes recommended
Vitamin C Level 0.2–0.4 mg/dL
- What it means: Moderate depletion
- Typical action: Increase dietary intake; consider supplementation
Vitamin C Level 0.4–2.0 mg/dL
- What it means: Adequate supply
- Typical action: Maintain balanced diet rich in fruits and vegetables
Vitamin C Level above 2.0 mg/dL
- What it means: High levels
- Typical action: Review supplementation; excess usually excreted safely
Approximately 7% of U.S. adults have vitamin C deficiency, with higher rates among smokers and elderly populations (NIH 2025).
Always discuss results with your healthcare provider for personalized interpretation and recommendations based on your complete health picture.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
For optimal accuracy, fast for 12 hours before your blood draw—water is allowed. Avoid vitamin C supplements, fortified foods, and high-dose ascorbic acid for 24 hours before testing, as these rapidly elevate plasma levels and may not reflect your typical nutritional status. Continue prescription medications unless your doctor advises otherwise. Inform lab staff if you're taking supplements so proper handling can ensure accurate results.
How often should I get tested?
Testing frequency depends on your health status and risk factors.
Initial nutritional assessment
- Suggested interval: Once, then retest after dietary changes
Monitoring supplementation
- Suggested interval: 6–8 weeks after starting therapy
Chronic malabsorption disorders
- Suggested interval: Every 3–6 months
After confirmed deficiency
- Suggested interval: 8–12 weeks post-treatment
General wellness monitoring
- Suggested interval: Annually or as symptoms appear
Consult your healthcare provider to determine the testing schedule appropriate for your individual circumstances.
Why early detection matters
Vitamin C deficiency progresses gradually, initially causing fatigue and weakness before advancing to serious complications like scurvy. Early detection prevents progression to severe symptoms including bleeding gums, tooth loss, joint pain, poor wound healing, and increased infection susceptibility (CDC 2025). Maintaining adequate vitamin C levels supports cardiovascular health—higher plasma concentrations correlate with approximately 29% lower coronary heart disease risk (Linus Pauling Institute 2025). Proactive testing enables dietary or supplement adjustments before deficiency compromises your health, reducing healthcare costs and improving quality of life.
Related tests you may consider
Complete Blood Count (CBC) with Differential and Platelets Blood Test - Evaluates blood cell types and levels to help diagnose health conditions and track treatment response.
Ferritin Blood Test - Measures ferritin levels in the blood to help screen for and monitor iron-related conditions.
Vitamin D 25-Hydroxy Blood Test - Checks if you have enough vitamin D, helping to ensure your bones stay healthy and reducing the risk of various health issues associated with vitamin D deficiency.
