Vitamin supplements do lose potency over time. However, after their expiration date, vitamins do not generally become unsafe to take.

The rate at which vitamins lose their potency depends on the form of the supplement, the storage methods, and the date of manufacture, according to a 2019 study.

In this article, we investigate the safety of taking expired vitamins. We also describe the best ways to store and dispose of these supplements.

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Vitamin supplements may not be potent enough after a certain date.

The shelf life of a supplement depends on its form, its contents, and how someone is storing it.

Chewable or gummy vitamins are more susceptible to moisture than capsules or tablets. Vitamins in tablet or capsule form may remain potent for several years.

Additionally, some vitamins may last longer than others. An older study, from 2008, indicates that vitamin C, vitamin K, and vitamin B-1, which is sometimes called thiamine, may break down more quickly than others.

Other factors that can contribute to vitamins losing potency include:

  • extreme temperatures
  • exposure to light
  • exposure to oxygen
  • pH levels

Unopened vitamin supplements are more likely to retain their potency because moisture, light, and oxygen are less likely to affect them.

It is worth noting that the Food and Drug Administration (FDA) do not require supplement manufacturers to provide expiry dates on vitamin or mineral supplements.

The companies may choose to include this information, but only when valid data support the date, and when it is not false or misleading. As a result, a person may prefer to only purchase supplements that contain expiration dates.

However, to ensure the quality of supplements, it is a better idea to choose those that have undergone independent third-party testing. These will advertise verification labels. The United States Pharmacopeia provide “USP Verified” certification, for example.

In general, it is relatively safe to take an expired vitamin supplement. It is unlikely to cause harm, as most expired medications and supplements do not usually become toxic.

Military-funded research, for example, reports that 90% of over 100 prescription and over-the-counter medications tested remained suitable for use, even 15 years after their expiry dates.

These findings suggest that expired medications are still generally safe to use — with some exceptions.

Regarding supplements, a person should not take those that:

  • show signs of mold
  • have a strange odor

Immediately dispose of vitamins that look moldy or damp or have an unusual smell.

As research indicates that expired vitamins are typically safe to take, these products are unlikely to cause side effects just because they are out of date.

However, if a person is unaware that their supplement has expired, they may believe that they are consuming more nutrients than they really are.

For example, a person on a vegan diet may need to take a vitamin B-12 supplement regularly to stay healthy. Taking an expired supplement may mean that they are not getting enough of the vitamin.

A vitamin B-12 deficiency can cause complications such as shortness of breath, depression, and neurological problems.

Overall, if a person relies on a supplement to fill a gap in their diet, they should keep track of the supplement’s expiration date.

Another example involves folic acid during pregnancy. Expired folic acid supplements may not deliver enough folate to the woman and the developing baby.

Consuming enough folic acid is important during pregnancy, as it decreases the likelihood of birth abnormalities.

Vitamin supplements can cause side effects, though this is unlikely to relate to their expiration. Anyone who experiences adverse effects of a nonessential supplement should stop taking it.

To ensure the maximum shelf life of vitamin supplements, it is best to store them in their original containers and in a cool, dry place out of direct sunlight.

To reduce the risk of heat and moisture affecting the supplements, it may not be advisable to store them in the kitchen or bathroom.

However, it is crucial to read the storage instructions for each supplement — on the bottle, packaging, or leaflet — carefully.

Instructions may be different for specific supplements. For example, a person can freeze some fish oil supplements to lessen their aftertaste, but other fish oil products should not be stored at temperatures below 59ºF.

The same is true for probiotics: Some are best kept in the fridge, while others should not be refrigerated.

Disposing of expired vitamins incorrectly increases the risk of children or animals consuming them, which could have serious consequences.

The FDA provide the following instructions for the disposal of unused medications. The same guidance can apply to expired vitamin or mineral supplements if there are no alternate instructions on their packaging:

  1. Remove the supplements from their containers.
  2. Mix them with coffee grounds, cat litter, or another unpleasant substance.
  3. Place the mixture in a sealable bag or container.
  4. Seal it and place it in a garbage can.

This deters animals and children from touching or eating the unwanted supplements.

Also, do not flush supplements down the toilet, as this can contaminate the water supply.

Vitamins and other supplements lose potency over time, and the expiration date can indicate when these supplements have lost a significant amount of potency. However, even then, they are not usually toxic.

Even so, taking expired supplements may lead to deficiencies if people believe that they are ingesting more of the nutrient than they really are.

It is a good idea to dispose of expired vitamins safely and purchase new products.