> The only vit that I know about that has studies showing supplements helps is D. Even that is not clear. We know that sick people often have lower D levels b

> The only vit that I know about that has studies showing supplements helps is D. Even that is not clear. We know that sick people often have lower D levels but we don’t know which way the causality runs. Or there could be no causality at all: low D levels could simply be correlated with a sedentary lifestyle which is the actual problem is some cases. Thus adjusting the level would be a waste of time.