Could a ray of sunshine hold the key to preventing MS, diabetes and even bowel cancer? Vitamin D - made naturally in skin exposed to strong sunlight - appears to reduce the risk of developing these, and a rash of other diseases. We examine the evidence to find out why as well as hearing how seaweed looks set to ignite a biofuel boom in the future, why a good night's sleep might make traumatic memories worse and how scientists have made multicellular life in the lab in just 60 days... Like this podcast? Please help us by supporting the Naked Scientists)