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...