What vitamins and supplements should you take, and can DNA tests help? Or is a healthy diet all you need? Experts explain, including which 3 nutrients we most likely lack

• With such a mind-boggling selection of dietary supplements on offer, firms have emerged offering DNA tests touted to reveal which supplements are right for you
• But their reliability is debated, as is the degree to which supplements should be taken. Dietitians give their take, and reveal which nutrients we commonly lack