Here we see the problem with the appeal-to-relative. I don't usually go about personally insulting people's relatives and yet simply by rejecting the superstition declared above shend's relative's competence is called into question.

Vitamin D supplements reduce the amount of calcium leeched from the bones (and excreted in urine) and actually increase our ability to absorb calcium from food. There is a reason a lot of calcium supplements also include vitamin D.

In the end, the best thing is simply sunlight.

For killing vampires yes, for getting vitamin D, not so much.

While the anecdote is interesting, cancer patients are perhaps not the best sample group for extrapolating to the healthy.