Vitamin D

A study published recently in JAMA Internal Medicine found that giving high monthly doses of vitamin D did not result in fewer falls and may even have resulted in more falls in people over 70. These results contradict the results of earlier studies that showed fewer falls in elderly people taking vitamin D supplements. My problem with this study is that it involves giving a high monthly dose, rather than a daily dose. Vitamin D, the sunshine vitamin, is produced by the body in response to sun exposure without sunscreen, or through the diet (some oily fish, mushrooms). I feel that the body utilizes vitamin D more optimally when given in a daily dose rather than a monthly dose. Are the studies with monthly dosing, or even yearly dosing, designed to show vitamin D to be ineffective? Are they maybe testing a dose that can best be consumed through a prescription rather than through supplements? I wonder why these studies are done in a fashion that does not try and mimic natural vitamin D production.