Vitamin C, vitamin D, collagen, creatine, magnesium. All of them can be found in supermarkets, wellness shops and of course, online. These products, also known as supplements, have gained so much popularity that the global market has an estimated value of over $150 billion.

But do they actually work and what’s the science behind them? The BBC’s Digital Health editor Michelle Roberts unpacks some of the most popular supplements for us. Plus we hear from people around the world about why they’ve decided to include them in their diet.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: William Lee Adams Producers: Chelsea Coates, Rio Rennalls and Maria Clara Montoya Editor: Emily Horler

How useful are your supplements?