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Question:
Do vitamins, minerals and nutritional supplements lose effectiveness with exposure to high temperatures and is it safe to order supplements by mail in the summer?

Answer:
Many vitamins and other supplements can degrade faster and lose effectiveness when exposed to excessive heat, light, oxygen in the air, or humidity. Even under ideal conditions, vitamins normally degrade over time, but this process is accelerated by poor storage conditions. Although overly degraded supplements may not be unsafe to take, you won't receive the amount of ingredient stated on the label and may not get the desired effect.

See the full answer for how different types of supplements are affected by the environment, particularly heat, and what you should do to protect them. Get the Full Answer >>


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Stephen16764   April 26, 2018
If a desiccant pack was not included in the bottle, is it safe to add one?

ConsumerLab.com   April 26, 2018
Hi Stephen - Yes, it should be safe to add one.

Stephen16768   April 26, 2018
Thank you!

ConsumerLab.com   April 26, 2018
You're welcome Stephen!

Roy16626   March 25, 2018
I get most of my Rx drugs and supplements by mail, but never during hot months or winter freezes. I keep out only what I need, then store the rest in double-sealed plastic bags with desiccant packs at 40F in my fridge. To avoid condensation I always bring them back to room temp before opening a sealed bag.
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I’m hoping to extend their life beyond the use-by-date. I commented on this back in 2016.
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The desiccant I’m using for this is: Stack-On Safe 'N Dry Spad-60 packets by DESICCARE, INC. These are a combination silica jell & activated charcoal desiccant pack, and are available as 10 packs for about $12 by ordering them from Wal-Mart.
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I’m also putting these in my dry hot cereals and beans to protect from yeast or mold.

Beverly15309   July 19, 2017
I have been in the practice of buying locally during the summer months to avoid exposure of supplements to heat while being shipped to my home. Today when I spoke with a local vitamin store retailer(in central North Carolina) about their "ship-to-store" option, he said those products were shipped the same as they are to your home, running the same risk of heat exposure. Then I asked if their store inventory products were protected from heat during shipment. He said they used to be via refrigerated trucks, but were no longer. So, my shopping locally is now not much of a guarantee of whether what I buy has been exposed to heat. I guess I'll have to get more organized to buy enough of a supply in the weather friendly months to get through the extreme hot/cold seasons.

Richard14072   June 2, 2017
"If you order supplements by mail, try not to order during excessively hot periods."

Could you provide some guidelines for what you consider "excessively hot"?

ConsumerLab.com   June 2, 2017
90 degrees Farenheit and above.

Daniel11071   July 10, 2016
Supplements and prescription medicines are often packed with a desiccant. Once the bottle is opened, is there any benefit leaving it in the bottle until the pills are finished?

ConsumerLab.com   July 11, 2016
Hi Daniel - Yes, as noted in the answer, if a desiccant packet was included, keep it in the bottle.

Roy9739   May 29, 2016
Considering the high cost of both Supplements and Prescription drugs obtaining the longest possible shelf life is very important.
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Years ago, I learned that our Federal Government stockpiles vast quantities of Rx drugs in caves, and that they undertook a project of determining if the use-by-date could be extended--and exactly how. Unfortunately they never shared their findings with the American people.
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They have the resources and ability to test the actual effectiveness of drugs after long storage; I do not.
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However, based on what it likely or logically true, I've started storing my supplements and Rx drugs under refrigeration at 40F in a sealed quart jar with a combination silica jell & activated charcoal desiccant pack inside it. I was able to obtain 10 packs for about $12 by ordering them from Wal-Mart. The Stack-On Safe 'N Dry Spad-60 packets have a color changing indicator, and can be recharged by heating at 200F in an oven for 6 hours. They're made by DESICCARE, INC.
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I may eventually to into freezer at 0F.
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I'd appreciate your comments about this.

Smitty

ConsumerLab.com   June 1, 2016
Dear Smitty - What you are currently doing may be more than you need to, but would not seem to do any harm. When you remove the container, let it get back to room temperature before opening, or you may get condensation inside the container. Storing at below freezing could potentially be a problem, as it could affect the chemical structure of products.

Helen16636   March 28, 2018
It would seem wise to store unopened and rarely used products in the refrigerator and then keep them at room temperature when using. I live overseas part of the time, and I keep several boxes in the vegetables compartment untouched for months. Should I also close them in a plastic bag?

ConsumerLab.com   March 28, 2018
Hi Helen - While it could not hurt to put them in a bag, there is little humidity in a refrigerator to be concerned about.

This CL Answer initially posted on 7/21/2012. Last updated 8/8/2017.

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