What this shows is a static picture comparing vitamin D levels and the above disease states. What this doesn't show is whether taking vitamin D will prevent these epidemic-level diseases in our communities.
The next step towards answering this, however, is already under way. These researchers started a research project last year comparing development of cardiovascular disease and insulin resistance (seen in diabetes and pre-diabetes) in groups taking either vitamin D, fish oil (high in omega-3 fatty acids) or placebo.
This study will continue for another five years, but these research findings could shed some light on dosage of these supplements and what disease risk factors doctors will confidently be affecting. I look forward to to resulte they may find, and will pass this information along when it becomes available.