Part 1 and Part 2 discussed on HN previously:
Vitamin D, part 1: back to basics - https://news.ycombinator.com/item?id=24138590
Vitamin D, part 2: Shannon's story - https://news.ycombinator.com/item?id=24261948
Part 1 and Part 2 discussed on HN previously:
Vitamin D, part 1: back to basics - https://news.ycombinator.com/item?id=24138590
Vitamin D, part 2: Shannon's story - https://news.ycombinator.com/item?id=24261948