How it works
questhealth.com offers 100+ consumer-initiated Quest Diagnostics lab tests to empower you to have more control over your health journey. Choose from a variety of test types that best suit your needs.
Vitamin C Test
Vitamin C Test
Vitamin C plays a key role in building and repairing tissue–including skin, bone, blood vessels, and connective tissue. It supports collagen production and wound healing, helps your body absorb iron to make red blood cells, and contributes to healthy teeth and gums. Because your body can’t make vitamin C, it must come from your diet. Measuring your vitamin C level can help you and your healthcare provider determine whether changes to your diet or supplements may be beneficial. Read moreTest details
Sample type:
Blood
Preparation:
Fasting (not eating or drinking anything except water) for 8-12 hours is recommended.
Certain supplements and medications can interfere with your test results. If you are concerned about any of your supplements or medications impacting your results, talk to your healthcare provider before your sample is collected to see if you should stop taking them and for how long.
$49.00
+ $6.00 Physician Service Fee
How
Blood
About the test
This test measures the level of vitamin C (ascorbic acid) in the blood. Vitamin C is essential for tissue repair and collagen production, which support the health of your skin, bones, blood vessels, teeth, and gums, and aids in wound healing. It also helps the body absorb iron to support red blood cell formation.
Your body can’t make or store large amounts of vitamin C, so it must be consumed regularly through food or supplements. Low vitamin C levels are most often caused by diets lacking fruits and vegetables but may also result from increased demand (such as during pregnancy, breastfeeding, or hyperthyroidism) or reduced absorption. Good dietary sources of vitamin C include strawberries, tomatoes, citrus fruits, broccoli, sweet peppers, and potatoes.
Consuming proper amounts of vitamin C has been linked to lowering the risk of certain conditions, like age-related macular degeneration. Measuring your vitamin C level can help you and your healthcare provider determine whether changes to your diet or supplements may be beneficial.
No doctor’s visit needed. Buy this vitamin C test and visit a nearby Quest location.
FAQs
If your body is not absorbing certain nutrients properly, your doctor may suggest you consider taking a supplement for that nutrient.
While it is unlikely to get too much of a nutrient if you are taking a supplement, getting too much, known as toxicity, is possible. Vitamin C is water-soluble, so excess is usually passed regularly in urine. However, very high doses from supplements may cause nausea, diarrhea, or stomach cramps. Always confirm a deficiency and discuss with your healthcare provider before increasing your supplemental intake.
Water-soluble and fat-soluble vitamins differ in how they are absorbed by the human body. A water-soluble vitamin dissolves in water and is easily absorbed by the body. Your body does not store these vitamins for long, so any extra will be eliminated in your urine. Because of this, it's important to consume them every day.
A fat-soluble vitamin dissolves in fats and oils and is absorbed with the fats you eat. Your body stores any extra in your liver or fatty tissues. Because of this, you don't need to consume them every day.
Antioxidants are substances that can prevent or slow damage to cells caused by oxidative stress. They interact with toxins called free radicals, to minimize their damage. Antioxidants can help prevent diseases like cancer and reduce your risk of heart disease.
You may be able to use your FSA or HSA funds to purchase lab tests at questhealth.com. Please review your FSA/HSA plan or check with a tax professional to confirm specific requirements for individual eligibility.
Our references
1. Merck Manual Consumer Version. Vitamin C Excess. Accessed November 19, 2025. https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-c-excess
2. Merck Manual Consumer Version. Vitamin C Deficiency. Accessed November 19, 2025. https://www.merckmanuals.com/home/disorders-of-nutrition/vitamins/vitamin-c-deficiency#Symptoms_v45106378
3. National Institutes of Health Office of Dietary Supplements. Vitamin C Fact Sheet for Professionals. Accessed November 19, 2025. https://ods.od.nih.gov/factsheets/VitaminC-HealthProfessional/
4. Mayo Clinic. Vitamin C. Accessed November 19, 2025. https://www.mayoclinic.org/drugs-supplements-vitamin-c/art-20363932
5. Cleveland Clinic. Scurvy. Accessed November 19, 2025. https://my.clevelandclinic.org/health/diseases/24318-scurvy
6. Travica N, Ried K, Sali A, Hudson I, Scholey A, Pipingas A. Plasma Vitamin C Concentrations and Cognitive Function: A Cross-Sectional Study. Front Aging Neurosci. 2019 Apr 2;11:72. doi: 10.3389/fnagi.2019.00072. PMID: 31001107; PMCID: PMC6454201.