Fizzy Sweets, Vitamin D, Mushrooms, Raw Kale

Jimmy Doherty wonders what gives fizzy sweets their fizz, and swots up on his chemistry, to see if he can harness their explosive power in a rocket. In Ireland, Kate Quilton asks if a range of vitamin-enriched mushrooms could help the one in five Britons who lack vitamin D. Meanwhile, Matt Tebbutt investigates headlines that claim that raw kale may be bad for you, and finds out if our breakfast smoothies are safe.