I don't need a book by a "naturopathic doctor", whatever that is, to tell me what the US NIH posts on their web site:
Inadequate calcium intake can lead to decreased bone mineral density, which can increase the risk of bone fractures. Supplemental calcium promotes bone mineral density and strength and can prevent osteoporosis. Recent scientific evidence, however, ...
www.ncbi.nlm.nih.gov
But getting enough K2 is just a matter of eating some rather common foods, like broccoli and pork. [edit: only from animal products. Plants contain vitamin K, not K2. Thanks to Paul for the PM.]
As for not having the flu for a long time, I haven't either, but I know the reason, and it's not vitamin D. I get a flu shot every year, and have been for as long as I can remember. Have you been getting flu shots?