We may earn money or products from the companies mentioned in this post.
If your collagen powder already contains vitamin C, a second bottle may be unnecessary. The first thing to check is how much vitamin C you usually get from food, fortified drinks, and the supplements you already take.
Quick answer. Vitamin C helps your body make collagen. If your usual intake meets your needs, taking collagen does not create a separate requirement for vitamin C. Human studies discussed below leave open whether adding more helps people whose intake is already adequate. NIH Office of Dietary Supplements
How vitamin C supports collagen production
Your body makes its own collagen from amino acids. Vitamin C helps enzymes modify parts of the developing collagen molecule, supporting the formation of its stable structure. Severe deficiency impairs this process and can weaken connective tissue. NIH vitamin C fact sheet
When you consume collagen, digestion breaks it into smaller peptides and amino acids. Making collagen inside your cells is a separate process. Evidence for vitamin C’s role in making collagen does not establish that a vitamin C tablet improves absorption of a collagen supplement. NIH vitamin C fact sheet · Human study of collagen derivatives
How much vitamin C do adults need?
The Food and Nutrition Board’s Recommended Dietary Allowances (RDAs) are daily intake references. These values apply to adults 19 and older. NIH recommended intakes
| Adults age 19 and older | Recommended daily intake |
|---|---|
| Women | 75 mg |
| Men | 90 mg |
| During pregnancy | 85 mg |
| While breastfeeding | 120 mg |
People who smoke need 35 mg more per day than the applicable recommendation. The 90 mg Daily Value on most US labels is a reference for comparing products. Use the recommendation for your age and life stage when assessing your usual intake. NIH vitamin C fact sheet
Common foods that supply vitamin C
NIH lists these approximate amounts. The form and serving size matter, especially when comparing raw and cooked foods. NIH food sources
| Food | Serving | Vitamin C |
|---|---|---|
| Raw red bell pepper | ½ cup | 95 mg |
| Orange | 1 medium | 70 mg |
| Kiwifruit | 1 medium | 64 mg |
| Cooked broccoli | ½ cup | 51 mg |
| Sliced strawberries | ½ cup | 49 mg |
For example, a medium orange and half a cup of cooked broccoli provide about 121 mg combined. This is an example of how portions add up across a day.
Count what you already take
Check the milligrams of vitamin C per serving on your collagen product, multivitamin, and any other supplements. Match each number to the serving you actually use. Include fortified foods and drinks when estimating your total.
Suppose a multivitamin provides 90 mg, a serving of collagen powder provides 60 mg, and an orange provides about 70 mg. That adds up to about 220 mg from those three items. Check your own labels, since formulas vary.
For examples of collagen products with different ingredients and serving sizes, see the collagen pills comparison.
Who may be more likely to fall short?
NIH identifies smoking, regular exposure to secondhand smoke, limited food variety, and some conditions that affect nutrient absorption as risk factors. The additional 35 mg recommendation applies to people who smoke. People exposed to secondhand smoke should aim to meet their usual RDA. NIH groups at risk
If you rarely eat foods that supply vitamin C, look at your typical intake over several days. A clinician or registered dietitian can help assess a possible gap, especially if a medical condition affects your diet or nutrient absorption.
What studies say about adding extra vitamin C
The gelatin and exercise study
Shaw and colleagues studied eight healthy men who drank beverages containing 0, 5, or 15 g of gelatin before exercise. Each beverage, including the control, contained 48 mg of vitamin C. The 15 g condition increased a blood marker linked to type I collagen formation. With vitamin C held constant, the experiment tested differences in gelatin intake. Its blood marker leaves questions about long-term effects on tendons, joints, or skin. Shaw et al., 2017
Studies of blended supplements
A trial by Bolke and colleagues measured skin outcomes after participants took a blend containing collagen peptides, vitamin C, and several other ingredients. The results apply to the tested blend. To estimate the separate contribution of added vitamin C, a study would need otherwise comparable formulas and account for participants’ starting vitamin C intake. Bolke et al., 2019
Together, these studies give little guidance on whether an adult who already gets enough vitamin C would benefit from buying another supplement. They also leave open whether taking the two products at the same time changes outcomes.
Upper limits and when to check with a clinician
The adult Tolerable Upper Intake Level is 2,000 mg per day from food and supplements combined. It is a ceiling for routine intake. Large doses can cause nausea, diarrhea, or stomach cramps. NIH upper limits and adverse effects
Ask your clinician before adding high doses if you have kidney disease, a history of kidney stones, or hereditary hemochromatosis. People receiving chemotherapy or radiation should check with their oncology team before taking vitamin C supplements. A pharmacist can review your supplements alongside your medications. NIH cautions and interactions
Frequently asked questions
Do I need to take collagen and vitamin C at the same time?
The studies discussed here leave that timing question unanswered. Start with your usual vitamin C intake and follow the directions for any product you use.
What if my collagen already contains vitamin C?
Count the amount in the serving you take toward your daily intake. Add what you get from food and other supplements, then compare that total with the intake recommendation for your age and life stage.
Does a higher vitamin C dose make collagen work better?
The studies reviewed here do not establish an added benefit for people already meeting their needs. The NIH reports that the body absorbs a smaller proportion of vitamin C at high oral doses. NIH vitamin C fact sheet
Conclusion
Check how much vitamin C you usually get before deciding whether to add a supplement. Food, fortified drinks, and products you already take may cover your needs. If your intake appears low or you have a condition that affects absorption, ask a clinician or registered dietitian how to address the gap.
For help reading collagen labels, see the guide to choosing a collagen supplement.