A person supplementing calcium for stronger bones may be making it harder for vitamin K to do one of its jobs – keeping excess calcium out of blood vessels. In people who are chronically vitamin K deficient, they may even be making it harder to keep their arteries soft, while they may be making it easier to keep their bones hard.
I believe vitamin K deficiency is quite common and a study of randomly selected elderly people in hospitals, with a whopping 75% deficiency, backed up the claim, and though the US government authorities cited the study, they ignored it in claiming that vitamin K deficiency is not a problem.
Is a background of vitamin K deficiency one of many problems with excessive calcium supplementation? Is this in part the meaning of the study done in Sweden on the mammography cohort? (BMJ2013;346:f228doi:10.1136/bmj.f228(Published13February2013))
In the absence of deficiencies the body tolerates reasonable supplementation with nutrients rather well. Not so, given deficiencies.