Do you get vitamin D from sunlight or just daylight? I've always been confused by this. I have red hair, and read somewhere that red haired people are very good at synthesising vitamin D from poor light, but then I read that people with red hair fair badly with MS, because they don't tend to get enough vitamin D when younger. I'm not sure if the reasoning behind this is that they stay out of the sun, or where more sunscreen, but that would only work if it were only sunlight that caused vitanmin D synthesis.
Also, I read recently that the in the US it was advised that children were supplemented to 400 IU of vitamin D. Anyone read anything contrary to this? I seem to remember reading that excess supplimentary vitamin D can cause kidney damage.