Vitamin C Supplement Guide
Evidence-based information on Vitamin C benefits, dosage, safety, and food sources — sourced from NIH, FDA, and PubMed.
Our assessment
The evidence shows that vitamin C is a well-studied supplement with a strong safety record for most people. Our assessment: for general immune support and antioxidant protection, a daily intake of 75–90 mg is sufficient for most adults, though higher doses may be used for specific situations under medical guidance NIH ODS ↗.
How it works
Think of vitamin C as a versatile support molecule for your body. It protects your neurons from oxidative and excitotoxic damage, modulates your hypothalamic-pituitary-adrenal stress response, increases nitric oxide synthesis for healthy blood flow and vasodilation, and regulates both your innate and adaptive immune responses NIH ODS ↗.
Safety profile
FDA received 89,295 total adverse event reports for this product. The most common side effects from taking too much vitamin C include diarrhea, nausea, and stomach cramps NIH ODS ↗ FDA FAERS ↗. If you have a condition called hemochromatosis, which causes your body to store too much iron, high doses of vitamin C could worsen iron overload and damage body tissues NIH ODS ↗. Vitamin C can also interact with certain medications, including chemotherapy agents, radiation therapy, statins, niacin, warfarin, and protease inhibitors NIH ODS ↗.
Our recommendation
Start with the recommended dietary allowance of 75–90 mg daily from food and supplements combined. Do not exceed the daily upper limit of 2,000 mg unless your healthcare provider advises otherwise. If you take any prescription medications, especially blood thinners or chemotherapy, consult your doctor before adding a vitamin C supplement NIH ODS ↗.
AI-assisted analysis based on NIH ODS, FDA, and PubMed data. Citations are linked to original sources.
Recommended Dosage
| Age | Male | Female | Pregnant | Lactating |
|---|---|---|---|---|
| 0-6 months* | 40 mg | 40 mg | ||
| 7-12 months* | 50 mg | 50 mg | ||
| 1-3 years | 15 mg | 15 mg | ||
| 4-8 years | 25 mg | 25 mg | ||
| 9-13 years | 45 mg | 45 mg | ||
| 14-18 years | 75 mg | 65 mg | 80 mg | 115 mg |
| 19+ years | 90 mg | 75 mg | 85 mg | 120 mg |
Source: National Academies of Sciences, Engineering, and Medicine. Always consult your healthcare provider for personalized dosage recommendations.
Drug Interactions
Vitamin C can interact with certain medications, including chemotherapy agents, radiation therapy, statins, niacin, warfarin, and protease inhibitors.
Check All InteractionsFood Sources
Fruits and vegetables are the best sources of vitamin C. Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors. Other good sources include red and green peppers, kiwifruit, broccoli, strawberries, Brussels sprouts, and cantaloupe.
Complete food source guideClinical Evidence
Vitamin C has been studied in 3+ clinical studies:
Dietary supplement consumption among active individuals in Saudi Arabia.Alsayegh AA · 2026
Patient Perceptions of Dietary Supplement Use and Kidney Stone Disease.Kim DD · 2026
Impact of Dietary Supplement Usage on Nutrient Adequacy and the Risk of Nutrient Excess Among Korean...Kim S · 2026
Health Goals This Supplement Supports
Frequently Asked Questions
What are the benefits of Vitamin C?
Vitamin C is an antioxidant that helps protect cells from damage. It is essential for collagen synthesis, immune function, and iron absorption. Regular intake of vitamin C may reduce the duration of the common cold.
How much Vitamin C should I take daily?
Refer to the Recommended Dosage table above. Individual needs vary by age, gender, and health status. Always follow the dosage on your supplement label and consult your healthcare provider.
What are the side effects of Vitamin C?
Taking too much vitamin C can cause diarrhea , nausea , and stomach cramps. In people with a condition called hemochromatosis , which causes the body to store too much iron, high doses of vitamin C could worsen iron overload and damage body tissues . The daily upper limits for vitamin C include intakes from all sources—food, beverages, and supplements—and are listed below.
Can I get enough Vitamin C from food alone?
Fruits and vegetables are the best sources of vitamin C. Citrus fruits, tomatoes and tomato juice, and potatoes are major contributors. Other good sources include red and green peppers, kiwifruit, broccoli, strawberries, Brussels sprouts, and cantaloupe.
Does Vitamin C interact with medications?
Vitamin C can interact with certain medications, including chemotherapy agents, radiation therapy, statins, niacin, warfarin, and protease inhibitors.
Key Takeaways
Medical Disclaimer: The information on this site is for informational purposes only and is not a substitute for professional medical advice. Always consult your healthcare provider before starting any supplement regimen.
FDA Disclaimer: * These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.