Does Refrigeration Destroy Vitamin C? The Truth on Food Storage

October 12, 2025 •

5 min read

Vitamin C is highly sensitive to heat, light, and oxygen, with some fresh produce losing a significant percentage of its vitamin C within a week of being refrigerated. However, the crucial question for those concerned about nutrition is, does refrigeration destroy vitamin C completely, or merely slow down its natural degradation process?

Quick Summary

Refrigeration does not destroy vitamin C but significantly slows its natural degradation process, which is primarily caused by oxidation, heat, and light. Proper cold storage, airtight packaging, and minimal processing are key to maximizing vitamin C retention in fruits and vegetables.

Key Points

Refrigeration slows degradation: The cold temperature significantly reduces the rate of oxidation and enzymatic activity that break down vitamin C.
Heat and light are the main culprits: High temperatures from cooking and exposure to light accelerate vitamin C destruction more than refrigeration ever could.
Time causes natural loss: Even under ideal conditions, vitamin C levels in produce decline over time, but refrigeration extends its freshness significantly.
Freezing is great for long-term: For extended storage, freezing is an excellent option, as long as appropriate pre-treatment like blanching is performed to maximize retention.
Proper handling is key: The way you wash, cut, and cook your produce has a bigger impact on vitamin C levels than cold storage.

Vitamin C, also known as ascorbic acid, is an essential water-soluble vitamin vital for immune function, collagen synthesis, and antioxidant protection. Unlike some other vitamins, our bodies cannot produce it, making dietary intake from fruits and vegetables necessary. But once harvested, the vitamin C content in produce is on a steady decline. Contrary to a common misconception, refrigeration is a crucial tool for slowing this process, not a cause of its destruction. The real culprits are external factors that accelerate vitamin C's natural breakdown over time.

The Science Behind Vitamin C Degradation

Vitamin C is one of the most fragile nutrients, making it highly susceptible to environmental factors. Its low thermal stability and tendency to oxidize are the primary reasons for its loss. Understanding these mechanisms helps explain why refrigeration is so beneficial for preservation.

Oxidation: The Primary Enemy

Oxidation occurs when vitamin C comes into contact with air. When exposed to oxygen, ascorbic acid is converted into dehydroascorbic acid, and then into other inactive compounds. This process is accelerated by light and heat, explaining why you might see a vitamin C serum change color over time. In fruits and vegetables, this enzymatic degradation is slowed by lower temperatures.

Heat and Light Sensitivity

Beyond oxidation, vitamin C is notoriously sensitive to heat and light. High cooking temperatures or prolonged cooking times can break down the vitamin, reducing its potency. Similarly, exposure to direct sunlight or fluorescent light can hasten the degradation process, which is why produce left on the counter loses nutrients faster than when stored in a dark, cool place.

Time and Water Solubility

Even in ideal conditions, vitamin C content naturally decreases over time after harvesting. Furthermore, because it is a water-soluble vitamin, it can leach out of food and into cooking liquids during boiling. If the liquid isn't consumed, the nutrients are lost.

Refrigeration's Role: Preservation, Not Destruction

Refrigeration is not a destructive process but rather a protective one. It significantly slows down the enzymatic activity and chemical reactions that cause vitamin C degradation. By keeping food cool, you extend the window of time in which the produce retains its peak nutritional value. For example, a study on broccoli showed that refrigeration at 0°C resulted in no vitamin C loss, while at 20°C, 56% was lost.

However, even refrigerated storage isn't a perfect shield. A long-term study found that after 7 days of refrigeration, raw spinach and broccoli experienced substantial vitamin C losses (up to 94% and 68%, respectively). This highlights that while refrigeration is better than room temperature, it does not stop degradation indefinitely. The key is to consume refrigerated produce in a timely manner.

Comparison of Storage and Processing Methods

To put refrigeration's effect into perspective, it's helpful to compare it with other food handling methods. The table below illustrates the relative impact of various techniques on vitamin C retention.


Method	Initial Vitamin C Loss	Long-Term Retention	Key Considerations
Fresh (Immediate Consumption)	Minimal to none	Not applicable	Best for maximizing nutrient intake if consumed shortly after harvest
Fresh (Refrigerated)	Varies, but slows degradation	Moderate loss over time; depends on produce type and storage duration	Excellent for short-term storage (under one week); consume promptly
Frozen (After Blanching)	Moderate to significant loss during blanching	Very high retention during frozen storage	Ideal for long-term storage; most loss occurs during the pre-freezing process
Room Temperature Storage	High; degradation accelerates compared to refrigeration	Low	Not recommended for perishable produce high in vitamin C
Cooking (Boiling)	Significant loss due to heat and leaching	Not applicable	The least effective method for preserving water-soluble vitamins like C
Cooking (Steaming/Microwaving)	Lower loss compared to boiling	Not applicable	Gentle methods that minimize contact with water and cooking time

Best Practices for Maximizing Vitamin C Retention

To ensure your diet is as rich in vitamin C as possible, follow these guidelines for handling your food, from the store to your plate:

Choose Fresh and Local: The fresher the produce, the more nutrients it retains. Opt for locally grown produce that has traveled shorter distances.
Store Properly: Place sensitive fruits and vegetables in the crisper drawer of your refrigerator, ideally in airtight containers or sealed bags. This minimizes air exposure and oxidation.
Wash Just Before Use: Wait until you are ready to use your produce to wash it. Excessive washing or soaking can cause water-soluble vitamin C to leach out.
Minimize Cutting: Chop or cut fruits and vegetables right before you plan to eat or cook them. Cutting increases the surface area exposed to oxygen and light, speeding up nutrient loss.
Opt for Gentle Cooking: Instead of boiling, choose quicker cooking methods with less water, such as steaming, microwaving, or stir-frying. If you do boil, save the nutrient-rich water for soups or sauces.
Don't Overcook: Cook food for the minimum time necessary to make it tender and safe to eat. The longer the cooking time, the greater the vitamin C loss.
Consider Freezing for Long-Term Storage: If you can't eat fresh produce quickly, freezing can be an excellent option for long-term preservation. For vegetables, blanching first can help preserve the vitamin C content during storage.

Conclusion: Don't Fear the Fridge

Ultimately, the science is clear: the answer to "does refrigeration destroy vitamin C?" is no. Refrigeration is one of the most effective and widely used methods for preserving the nutritional value of fruits and vegetables over the short term. While some vitamin C loss is inevitable with any storage method due to the effects of time, light, and oxidation, refrigeration actively works to slow these degradation processes. By combining proper cold storage with smart preparation and cooking techniques, you can maximize your intake of this essential vitamin and ensure you get the full nutritional benefit from your produce.

For more information on the benefits of Vitamin C, visit The Nutrition Source at Harvard T.H. Chan School of Public Health.

The Verdict: Don't Fear the Fridge

Frequently Asked Questions

While fresh, peak-ripeness produce eaten immediately has the highest vitamin C content, frozen fruits and vegetables are an excellent alternative. They are flash-frozen soon after harvest, preserving nutrients, and often contain more vitamin C than fresh produce that has been refrigerated for several days.

The act of freezing itself has little negative effect on vitamin C, but the pre-freezing process (like blanching) can cause some initial loss. However, once frozen, vitamin C levels remain stable for long periods, often outlasting fresh, stored produce.

Microwaving and steaming are the best cooking methods for preserving vitamin C because they involve shorter cooking times and less contact with water than boiling. Boiling is the least effective method, as the water-soluble vitamin can leach into the cooking liquid.

This belief is likely a misunderstanding of how vitamin C degrades. The vitamin is inherently unstable and starts to break down immediately after harvesting. While the cold slows this, the inevitable, though slower, loss may be mistaken for a destructive effect of refrigeration itself.

It is best to store produce whole and cut it right before consumption. When you cut fruits and vegetables, you increase their surface area, exposing more vitamin C to oxygen and accelerating the degradation process.

Yes, some produce retains vitamin C better than others. For example, some studies have shown that leafy greens like spinach and broccoli lose more vitamin C in refrigeration over a week than other vegetables or fruits.

Yes, using airtight containers or sealed bags in the refrigerator helps minimize exposure to oxygen, which is a major driver of oxidation. This is a simple and effective way to help preserve vitamin C.