FWIW … [I don’t plan to change my routine. I take both, but not every day.]
While vitamin D and calcium are important for bone health and muscle function, the task force, a blue-ribbon panel of experts in disease prevention and evidence-based medicine, said the supplements do little to reduce falls or fractures, and they may increase the risk of kidney stones.
The task force said the recommendation applies to people living at home, including women who have gone through menopause and men 60 years and older. It does not apply to people in assisted living or nursing homes because people living in those facilities may be more prone to health complications, including risk of falls.
What could help prevent falls is good balance & muscle strength – there is some thought that calcium & vitamin d could be active against sarcopenia (says google).
Again from google, a certain amount of trouble with balance results from lack of strength.