A small study in mice showed that the dose of vitamin D is five times the current recommended dose for the elderly, which may slow the development of frailty. However, researchers now need to confirm this discovery in humans. Doctors currently define a person as "weak" if they show three or more of the following five characteristics: Unexpected weight loss, weak grip, self-reported exhaustion, low physical activity level, slow walking speed. Vulnerability tends to increase with age, affecting approximately half of people over 85. It is related to disability, loss of independence and rising mortality. Studies have shown that people with low levels of vitamin D in the blood are more likely to become vulnerable. This is a particularly urgent issue, because one billion people may not have enough levels globally. https://eu.echemi.com/info/study-high-dose-vitamin-d-can-slow-down-aging-and-frailty_126071.html