"Ryan became the face of a YouTube campaign to publicise the use of vitamin D, and led hundreds of supporters down Edinburgh's Royal Mile to Holyrood before he put his proposals to the petitions committee in June.
He told MSPs research into the genetic effect of vitamin D deficiency showed a link to the development of MS. Vitamin D, which the body needs for healthy, strong bones is largely gained through sunlight and food."
Living in Scotland tends to result in extreme Vitamin D deficiency because of chronic lack of sunlight. While deficiency in the UK is widespread the situation in Scotland is worse than for the rest of the country. Scotland receives 30-50% less ultraviolet radiation (UVB) from the sun than the rest of the UK owing to its high latitude and persistent low cloud cover.
Scotland is thought to have the highest rate of MS in the world.