5th March, 2010
An article has appeared in the popular press which alleges that “supplements can become useless in as little as week if stored in kitchens and bathrooms”.
The article has originated from the findings of two studies that examined the effects of deliquescence (the process by which a soluble substance picks up water vapour from the air to form a solution) on the stability of powdered vitamin C, thiamin and vitamin B6. Unsurprisingly the research found that storage conditions, specifically relative humidity and temperature, affect the shelf life and functionality of these nutrients.
This has long since been accounted for by the supplements industry. Higher quality supplements are being stability tested according to protocols set by the International Conference on Harmonisation (ICH, designed for the pharmaceutical industry).
Quest products as sold have been subject to rigorous, long term stability testing in order to establish shelf-life. In line with the ICH protocols 3 batches of each product are, on an annual basis, tested in standard and accelerated conditions. Standard conditions are 30°C at 65% humidity; these tests are conducted over a 3 year period. Accelerated conditions are 40°C at 75% humidity; these tests are conducted over 6 months (which equates to two years at standard conditions). Taken together the results of these tests indicate the stability of the active ingredients in conditions of average and above average temperature and humidity; these tests enable us to guarantee that the products will maintain their potency until the end of shelf life whether they are in a home in
Supplements are ideally stored in a cool, dry cupboard; this is clearly stated on the label. The press article referred to supplements being consumed and stored in bathrooms, this is not usual practice and is not in line with the storage instructions included on supplement labels.
As with much of the media coverage of nutritional supplements this article demonstrates a profound lack of understanding of the industry. Thankfully most supplement users have the experience and common sense to disregard “scare stories” such as this.
Click here and here to read the abstracts of the articles from which the newspaper story was derived.
