> I just want to share an observation about articles like this. It's that I never hear the same thing later from my doctor. Either doctors stick with their old

> I just want to share an observation about articles like this. It's that I never hear the same thing later from my doctor. Either doctors stick with their old methods -- what they were taught in medical school -- or the online information is a little premature. Why would you expect your doctor to recommend this to you? Unless you're a young, healthy, overweight African-American, this study doesn't really apply to you (and you're probably not at great risk of arterial stiffness anyway). > but further studies don't turn it into an actionable prescription regiment They do, but it takes a long time for this to happen, because medicine is incredibly complex, and there are all sorts of confounding factors that need to be investigated before general-purpose recommendations can be made. Otherwise, it can actually be counterproductive. Hypothetically: 4000 IUs of Vitamin D daily could decrease the risk of arterial stiffness in overweight African-Americans, but taking more than 2000IU could increase the risk of liver or kidney problems in East Asians[0], and it could also increase the risk of congestive heart failure in diabetic African Americans[1]. That's not even a particularly complex situation, because breaking down by broad race categories is pretty cookie-cutter, and diabetes is one of the most-problematic comorbidities. But all sorts of these things need to be studied before we make broad medical recommendations, because if we jump the gun, we could end up causing major health problems across the general population. [0] This is completely made-up and hypothetical; I'm not actually suggesting that 2000 IUs of Vitamin D is harmful. [1] Which, incidentally, may still not be a strong enough reason not to recommend it, if arterial stiffness is considered to be a greater risk than CHF.