Should You Store Your Vitamins in the Fridge? The Surprising Truth

December 28, 2025 •

4 min read

According to a study by Purdue University, moisture can cause significant degradation in water-soluble substances like certain vitamins, potentially reducing their effectiveness over time. This raises a common question for many supplement users: should you store your vitamins in the fridge to protect them from heat?

Quick Summary

Most vitamins and supplements are best kept in a cool, dry, and dark place to maintain their potency and prevent degradation. Some specific exceptions, such as probiotics, liquid supplements, and fish oils, may require refrigeration.

Key Points

Most Vitamins: Avoid refrigerating most solid pill and capsule vitamins due to high moisture, which can degrade potency.
Check the Label: Always follow the manufacturer's specific storage instructions, as requirements vary by product.
Probiotics and Oils: Some specific supplements, like probiotics, liquid vitamins, and fish oil, often require refrigeration to maintain effectiveness.
Cool and Dry: The ideal storage location for most supplements is a cool, dry, and dark place, like a bedroom drawer or a closet.
Avoid Heat and Humidity: Never store vitamins in the bathroom or near kitchen heat sources, as these environments accelerate degradation.
Original Container: Keep supplements in their original opaque containers to protect them from light and air.

The Problem with Refrigerating Most Vitamins

While it seems logical that a cold environment would preserve your vitamins, the refrigerator is actually a high-moisture area that can do more harm than good for most standard supplements. The cool temperature causes condensation to form inside the bottle each time you open and close it, trapping moisture that can accelerate the degradation of the active ingredients. This is especially detrimental for moisture-sensitive tablets, capsules, and gummies, which can lose potency, stick together, or even promote mold growth.

The Enemies of Vitamin Potency

Several environmental factors besides temperature directly impact a vitamin's shelf life and efficacy. Protecting your supplements from these elements is crucial for ensuring you get the full health benefits from each dose.

Heat: Excessive heat is a primary culprit for vitamin degradation. Temperatures above 77°F (25°C) can cause many vitamins, especially water-soluble ones like C and B-complex, to break down at a molecular level.
Humidity: As mentioned, moisture is a major threat. A study found that vitamin C content can be severely impacted by high humidity, and this moisture can also cause capsules and gummies to stick together or grow mold.
Light: Direct sunlight and UV rays can trigger oxidation reactions that degrade sensitive vitamins like A and E, as well as omega-3 fatty acids. This is why most supplements are sold in opaque or amber bottles.
Oxygen: Exposure to air, particularly during repeated opening and closing, can also cause oxidation. Manufacturers often include oxygen absorbers or seal products to minimize this, but it's important to keep lids tightly sealed after use.

Vitamins That Benefit from Refrigeration

Not all supplements are created equal, and some are specifically designed to be stored in the fridge. These products typically contain ingredients that are live, liquid, or highly susceptible to oxidation. You should always check the product label for specific instructions, but here are some common examples:

Probiotics: These supplements contain live microorganisms that are sensitive to heat and temperature fluctuations. Refrigeration helps keep the bacteria dormant and alive, ensuring the product's effectiveness.
Fish Oil & Flaxseed Oil: Rich in delicate omega-3 fatty acids, these oils are highly prone to oxidation, which can cause them to go rancid. Storing them in the fridge slows down this process and helps maintain a fresher taste.
Liquid Vitamins: Liquid formulations, including liquid iron, often require refrigeration to preserve freshness and potency, as the ingredients are not protected by a capsule or tablet shell.
Select Vitamin C Formulations: While most solid vitamin C supplements are fine at room temperature, some liquid or specially formulated versions may benefit from refrigeration to prolong potency, especially in warm, humid climates.

Optimal Storage Solutions for Most Supplements

For the majority of your vitamins, including multivitamins and solid forms of vitamins D, E, and K, the best storage solution is simple and straightforward. Proper storage helps to maximize their shelf life and effectiveness.

Here are some best practices:

Keep it Cool and Dry: Store supplements in a location with stable, moderate temperatures, typically between 59° and 77° F (15°-25° C). A bedroom drawer, linen closet, or a kitchen cabinet away from the stove and sink is ideal.
Original Container: Never transfer supplements into a different, potentially non-opaque or non-airtight container. The original packaging is specifically designed to protect its contents from light and air.
Avoid the Bathroom and Kitchen: Steer clear of the bathroom medicine cabinet and kitchen counters. These areas experience significant temperature swings and high humidity from showers and cooking, which can quickly degrade supplements.
Protect from Children: Always store supplements in a location that is out of reach of children to prevent accidental ingestion.

Signs of Vitamin Degradation

It's important to recognize when a supplement has lost its potency, even if it has been stored correctly. Signs of degradation may include:

An unusual or unpleasant odor (e.g., a fishy smell in vitamin D or sulfur in B vitamins)
Significant discoloration or brown spots on tablets or capsules
A change in texture, such as a hardening or softening of gummies or softgels
Condensation or moisture droplets visible inside the bottle

Storage Location Comparison


Storage Location	Pros	Cons	Ideal For
Refrigerator	Cool temperature slows degradation for sensitive products.	High humidity can cause moisture damage to most pills/capsules.	Probiotics, fish oil, liquid vitamins, specific vitamin C.
Bathroom Cabinet	Convenient for daily use.	Frequent humidity and temperature fluctuations are terrible for most supplements.	Nothing. A poor choice for all supplements.
Kitchen Cabinet	Accessible near mealtime for taking vitamins with food.	Areas near the stove and sink can get hot and humid.	General storage if kept away from heat/moisture sources.
Bedroom Drawer	Offers a consistently cool, dark, and dry environment.	Can be out of sight, out of mind for some people.	Most multivitamins and solid supplements.

Conclusion: Always Read the Label

The best advice for vitamin storage comes directly from the source. Always check the manufacturer's storage recommendations on the product label before deciding where to keep your supplements. While the standard advice is a cool, dry, and dark location, certain products like probiotics and fish oil are clear exceptions and require refrigeration to maintain their potency. By storing your supplements correctly, you ensure their effectiveness and protect your investment in your health. To learn more about supplement quality, visit ConsumerLab.com.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before starting any new supplement regimen.

Frequently Asked Questions

You shouldn't store most vitamins in the fridge because the high humidity and condensation can introduce moisture into the bottle. This moisture can cause tablets and capsules to degrade, reducing their potency and potentially leading to mold.

The best place to store most vitamins is a cool, dry, and dark location. A bedroom drawer, a linen closet, or a kitchen cabinet away from the stove and sink are all excellent options.

Yes, all vitamins lose some potency over time, even under ideal storage conditions. However, improper storage in hot or humid environments can significantly accelerate this degradation process.

Certain supplements benefit from refrigeration, including probiotics, liquid vitamins, fish oil, and flaxseed oil. These products are often more sensitive to heat and require colder temperatures to maintain their stability.

Taking an expired vitamin is not typically dangerous, but it may be a waste of money because the product has likely lost some of its potency. For best results and guaranteed effectiveness, it's best to discard expired supplements.

While convenient, transferring supplements from their original container to a pill organizer can expose them to light, air, and moisture. This can reduce their shelf life and potency, especially for more sensitive vitamins.

Signs of vitamin degradation can include an unusual smell (like sulfur in B vitamins), discoloration (brown spots or changes in color), or a change in texture. Visible condensation inside the bottle is also a sign of moisture exposure.

Most vitamins should be stored at a stable room temperature, ideally between 59° and 77° F (15°-25° C).