11 You Can’t Get Too Much of a Good Thing

Flooding your body with synthetic vitamins in the hope of reaching nutritional nirvana does not work. Micronutrients offer diminishing returns: “Many are ‘hormetic’ – they have an increasingly beneficial impact up to a certain point, then above that, they begin to have an adverse effect,” says Roberts. Take, for example, vitamin C: the “upper tolerable limit” is 2,000mg per day, after which you might experience side effects such as nausea or trouble sleeping. Read the labels and, if you’re worried about deficiencies, get a blood test before topping up.