The ancient Egyptians knew what to do when it came to treating night blindness, a disease now known to be caused by a vitamin A deficiency. It is often hoarded due to how common the disease is.
We now know that the real therapeutic benefit comes from eating liver, because animal liver – including fish liver – is very rich in vitamin A.
Today, when it comes to healthy eating, we often prefer to swallow vitamins and supplements in tablet form. But while it’s unlikely to change its look and smell over time, its potency diminishes with age.
All vitamins and supplements come with a “best before” date on their label, and while they won’t expire in the traditional sense of being unsafe to digest, they will be rendered worthless if taken after that date. This is because most ingredients in vitamins and supplements gradually break down, which means that they become less effective over time.
Storage is vital, because vitamins in tablet form often retain their potency for several years when kept in appropriate conditions, ie in their original packaging and in a cool dry place. And there may be problems if the product itself is not stored properly before it reaches stores.
Research published this week found that many popular omega-3 fish oil supplements are “rancid,” which arises when the product is oxidized. Fish oil is particularly susceptible to oxidation, which occurs faster when exposed to heat, air, or light.
More than one in 10 fish oil supplements tested among 60 large retail brands are found to be spoiled, with nearly half just below the maximum recommended amount for rancidity, according to independent tests.
So where better to keep vitamins? The two favorite locations – the kitchen and the bathroom – are the worst places as they usually have more heat and humidity than other rooms.
Scientists suggest a linen closet or a bedroom drawer. They should also not be exposed to light because some vitamins – including A and D – lose their effectiveness. Refrigeration can also help extend the shelf life of products, such as fish oil and vitamin E, that are less stable at room temperature.
The typical shelf life of most vitamins is two years although this may vary, depending on the type of vitamin and the conditions it is exposed to. Vitamin gummies and chewable vitamins absorb more moisture than vitamins in tablet form, and therefore tend to deteriorate faster.
Most product labels will advise you to consume the contents within a certain number of months after opening. Unopened supplements are more likely to retain their potency as moisture, light, and oxygen are less likely to be affected.
Expired vitamins are usually safe to take and not likely to cause side effects, but if you aren’t aware that your supplement has expired, you may think you’re consuming more nutrients than you actually are.
Vegetarians may need to take a vitamin B12 supplement regularly but taking an expired supplement may mean they are not getting enough. This can be dangerous because a deficiency can cause shortness of breath, depression, and neurological problems.
Pregnant women taking folic acid should pay special attention to expiration dates, because expired folic acid supplements may not provide enough folic acid to the woman and the developing baby, increasing the risk of birth defects.