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Most vitamin products maintain their integrity and freshness if kept tightly sealed and stored at room temperature. However, some vitamins and supplements require refrigeration to retain their freshness and usefulness. These include liquid vitamins, some essential fatty acids and probiotics. Supplements in capsules have casings that protect them from oxidation and therefore do not need refrigeration.

Liquid Vitamins

Liquid vitamins are fresher and more potent than pill form, so they require refrigeration to maintain this freshness and potency. Vitamin pills contain preservatives that increase their shelf life. Since liquid vitamins do not contain these additives they require refrigeration, according to DoctorYourself.com.

Fish Oils

Fish oils are an essential fatty acid. Because of the high levels of omega-3, fish oil supplements can reduce cholesterol and possibly reduce inflammation. Liquid formulas are light-sensitive, which is why they are usually packaged in opaque bottles. Once you have opened them, they are also exposed to oxygen and can spoil if left out of the refrigerator. Refrigerating them also cuts down on the fishy after taste, according to AllAboutVision.com.

Flaxseed Oil

Like fish oil, flaxseed oil is a good source of omega-3 essential fatty acid. It is also a great source of fiber and protein. Flaxseed oil contains a high concentration of phyto-nutrients that are beneficial to human health, according to the National Center for Complementary and Alternative Medicine. Also, like fish oil, flaxseed oil can help reduce inflammation and cholesterol. If flaxseed oil is in liquid form, seal tightly and refrigerate after opening.


Probiotics are health-promoting bacteria used for digestive health. Forms of probiotics include acidophilus and other live bacteria supplements, reports Harvard Health Publications. Since they contain active cultures that can die if exposed to heat, light and air, it is essential that you refrigerate them.